JP2012039430A - Audio output device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an audio output device capable of conducting a performance test with high reliability.SOLUTION: The audio output device includes a power amplifier which generates a speaker driving signal by amplifying an audio signal and a control part having an amplifier protection processing function which restricts or stops operation of the power amplifier under abnormal conditions. The control part turns on the amplifier protection processing function (step S3) in a default state (No, in a step S1), and turns off the amplifier protection processing function (step S2) when receiving input of a special key (Yes, in the step S1).

Description

  The present invention relates to an audio output device including a power amplifier that amplifies an audio signal to generate a speaker drive signal.

  Conventionally, an audio output device equipped with a power amplifier that amplifies an audio signal to generate a speaker drive signal has a temperature abnormality from the power amplifier in order to prevent a dangerous temperature rise of the power amplifier during audio output from the speaker. It is equipped with a function (so-called amplifier protection processing function) that monitors the signal by the control unit and restricts or stops the operation of the power amplifier when an abnormality occurs.

  As an example of the related art related to the above, Patent Document 1 can be cited.

JP 2008-236621 A

  Certainly, an audio output device having an amplifier protection processing function can prevent a dangerous temperature rise of the power amplifier.

  However, when performing a performance test of the audio output device, the amplifier protection processing function can interfere with the performance test. For example, if the amplifier protection processing function is activated during a limit performance test to evaluate how long a sound output device can withstand without failing while the speaker is continuously driven at the maximum volume, The limit performance of the output device itself cannot be correctly evaluated.

  Therefore, in the past, a test firmware that does not have an amplifier protection processing function is prepared separately from a product version firmware that has an amplifier protection processing function. Was introduced, and the test output was introduced to the audio output device targeted for performance testing.

  However, conventionally, only for performing a performance test of the audio output device, a test firmware different from the product version firmware has to be prepared, and the performance test cannot be easily performed.

  In addition, in the past, the performance of audio output devices that were actually put on the market (audio output devices in which product version firmware was introduced) could not be directly evaluated. There was room for further improvement.

  In view of the above problems, an object of the present invention is to provide an audio output device capable of easily performing a highly reliable performance test.

  In order to achieve the above object, an audio output device according to the present invention includes a power amplifier that amplifies an audio signal to generate a speaker drive signal, and an amplifier protection processing function that restricts or stops the operation of the power amplifier when an abnormality occurs. An audio output device comprising: a control unit comprising: a control unit configured to turn on the amplifier protection processing function in a default state and turn off the amplifier protection processing function when an input of a special key is received (First configuration).

  In the audio output device having the first configuration, the operation mode switching function according to the input of the special key is programmed as a function of firmware executed by the control unit (second configuration). ).

  In the audio output device having the first or second configuration, the special key may be provided only on the test remote controller (third configuration).

  In the audio output device having any one of the first to third configurations, the control unit may detect a temperature abnormality signal from the power amplifier or a temperature detection signal of a temperature sensor provided in the vicinity of the power amplifier. It is preferable to adopt a configuration (fourth configuration) for monitoring whether or not there is a temperature abnormality.

  Further, in the audio output device having any one of the first to fourth configurations, the control unit may reduce the power amplifier, reduce the power amplifier in order to limit or stop the operation of the power amplifier when an abnormality occurs. A configuration (fifth configuration) may be employed in which at least one of output mute, power supply stop to the power amplifier, and interruption of audio signal input to the power amplifier are executed.

  With the audio output device according to the present invention, since it is not necessary to prepare a plurality of types of firmware, it is possible to easily perform a performance test and to increase the reliability of the performance test. .

The block diagram which shows the example of 1 structure of the home theater system which concerns on this invention Schematic diagram showing the contents of the product version firmware executed by the control unit 112 Flow chart showing an example of operation mode switching control Schematic showing the differences between the product version remote control and the test remote control Schematic diagram showing the differences between conventional product version firmware and test firmware

<System block diagram>
FIG. 1 is a block diagram showing a configuration example of a home theater system according to the present invention. The home theater system of this configuration example includes a television broadcast receiving device 100 and a home theater device 200.

  The television broadcast receiving apparatus 100 includes an antenna 101, a tuner 102, a demodulation IC 103, a demultiplexer 104 (hereinafter referred to as DEMUX 104), a video decoder 105, an OSD [On Screen Display] processing unit 106, and a video output. Unit 107, liquid crystal panel 108, audio decoder 109, power amplifier 110, speaker 111, control unit 112, remote control signal receiving unit 113, operation unit 114, and HDMI (High-Definition Multimedia Interface) communication unit 115 and a remote control 116. Of the above components, the antenna 101 and the remote controller 116 are provided outside the television broadcast receiving apparatus 100.

  The antenna 101 is externally connected to the television broadcast receiving apparatus 100, converts a broadcast wave into an electrical reception signal, and outputs it. In FIG. 1, the configuration in which the antenna 101 is directly connected to the television broadcast receiving apparatus 100 is depicted. However, the configuration of the present invention is not limited to this, and for example, when viewing cable TV. Between the antenna 101 and the television broadcast receiver 100, cable television equipment (amplifier, distribution device, etc.) is provided.

  The tuner 102 selects a broadcast signal having a channel selection frequency from the digital broadcast signal received by the antenna 101, and outputs the selected broadcast signal to the demodulation IC 103.

  The demodulation IC 103 demodulates the broadcast signal selected by the tuner 102 by an OFDM (Orthogonal Frequency Division Multiplexing) method, and performs error correction using Viterbi decoding or the like, thereby extracting TS [Transport Stream] data.

  The DEMUX 104 extracts a video stream from the TS data and outputs it to the video decoder 105, extracts an audio stream from the TS data, and outputs it to the audio decoder 108.

  The video decoder 105 decodes the video stream input from the DEMUX 104 to generate digital video data, and outputs this to the video output unit 107 via the OSD processing unit 106.

  The OSD processing unit 106 superimposes and outputs the OSD video data input from the control unit 112 on the digital video data input from the video decoder 105.

  The video output unit 107 generates a drive signal necessary for a display operation on the liquid crystal panel 108 based on the digital video data input via the OSD processing unit 106, and outputs this to the liquid crystal panel 108.

  The liquid crystal panel 108 displays an image based on the drive signal input from the image output unit 107. In addition to the liquid crystal panel, other types of panels such as a plasma display panel and an organic EL panel may be used.

  The audio decoder 109 decodes the audio stream input from the DEMUX 104 to generate digital audio data, and outputs this to the power amplifier 110.

  The power amplifier 110 generates a driving signal for the speaker 111 based on the digital audio data input from the audio decoder 109, and outputs this to the speaker 111.

  The speaker 111 converts the drive signal input from the power amplifier 110 into sound and outputs the sound. Thereby, the television broadcast sound is reproduced from the speaker 111.

  The control unit 112 is configured using, for example, a microcomputer, and comprehensively controls operations of the respective parts of the television broadcast receiving apparatus 100 by executing firmware stored in a memory (not shown).

  The remote control signal receiving unit 113 receives a remote control signal corresponding to the user's key operation from the remote control 116, converts it into a remote control code, and outputs it to the control unit 112. The control unit 112 performs various operation controls (power on / off, channel selection channel change, volume change, input switching, etc.) according to the remote control code input from the remote control signal receiving unit 113.

  The operation unit 114 receives a user's direct operation, generates an operation code, and transmits the operation code to the control unit 112. The control unit 112 performs various operation controls (power on / off, channel selection channel change, volume change, input switching, etc.) according to the operation code input from the operation unit 114.

  The HDMI communication unit 115 transmits and receives audio signals and control signals to and from the HDMI communication unit 202 provided in the home theater device 200.

  The remote control 116 receives a key operation, generates a remote control signal, and outputs it to the remote control signal receiving unit 113. Note that an infrared signal is generally used as the remote control signal, but the configuration of the present invention is not limited to this, and a wireless signal of another method (for example, a Bluetooth signal) may be used.

  The home theater device 200 includes an information display unit 201, an HDMI communication unit 202, a control unit 203, a remote control signal reception unit 204, an operation unit 205, a sound source unit 206, a signal processing unit 207, a power amplifier 208, And a speaker 209. Of the above components, the remote controller 210 is provided outside the home theater device 200.

  The information display unit 201 displays the operation state of the home theater device 200 (input source (internal sound source / external sound source), playback track number, elapsed playback time, volume value, operation mode (normal mode / test mode), etc.). . In addition, as the information display part 201, a liquid crystal panel, a FL display tube, etc. can be used, for example.

  The HDMI communication unit 202 transmits and receives audio signals and control signals to and from the HDMI communication unit 115 provided in the television broadcast receiving apparatus 100.

  The control unit 203 is configured by using, for example, a microcomputer, and comprehensively controls the operation of each unit of the home theater device 200 by executing firmware stored in a memory (not shown).

  The remote control signal receiving unit 204 receives a remote control signal corresponding to the user's key operation from the remote control 210, converts it into a remote control code, and outputs it to the control unit 203. The control unit 203 performs various operation controls (power on / off, volume change, input switching, equalizer adjustment, etc.) according to the remote control code input from the remote control signal receiving unit 204.

  The operation unit 205 receives a user's direct operation, generates an operation code, and transmits this to the control unit 203. The control unit 203 performs various operation controls (power on / off, volume change, input switching, equalizer adjustment, etc.) according to the operation code input from the operation unit 205.

  The sound source unit 206 reproduces various media (CD [Compact Disc], DVD [Digital Versatile Disc], BD [Bluray Disc], hard disk, etc.) and outputs an audio signal.

  The signal processing unit 207 performs predetermined signal processing on the audio signal input from the sound source unit 206 or the audio signal input from the television broadcast receiver 100 via the HDMI communication unit 202 to generate digital audio data. This is output to the power amplifier 208.

  The power amplifier 208 generates a drive signal for the speaker 209 based on the digital audio data input from the signal processing unit 207, and outputs this to the speaker 209.

  The speaker 209 converts the drive signal input from the power amplifier 208 into sound and outputs the sound. Thereby, the media playback sound and the television broadcast sound are output from the speaker 209. As the speaker 209, a 2-channel stereo speaker (front left / right), a 5.1-channel surround speaker (front left / right, rear left / right, center, and subwoofer), or 7.1 channel Surround speakers (front left / right, side left / right, rear left / right, center, and subwoofer) can be used.

  The remote controller 210 receives a key operation, generates a remote control signal, and outputs it to the remote control signal receiver 204. Note that an infrared signal is generally used as the remote control signal, but the configuration of the present invention is not limited to this, and a wireless signal of another method (for example, a Bluetooth signal) may be used.

<Amplifier protection processing function>
In the home theater device 200 having the above-described configuration, the control unit 203 monitors a temperature abnormality signal from the power amplifier 208 in order to prevent a dangerous temperature rise of the power amplifier 208 during the sound output from the speaker 209. A function for limiting or stopping the operation 203 (so-called amplifier protection processing function) is provided.

  The temperature abnormality signal may be output from the power amplifier 208, or may be output from a separate temperature sensor (not shown in FIG. 1) provided in the vicinity of the power amplifier 208. Based on the detection signal, the controller 203 itself may determine whether there is a temperature abnormality. Moreover, it is good also as a structure which performs an amplifier protection process not only at the time of temperature abnormality but when other abnormality is detected.

  Further, as a method of restricting or stopping the operation of the power amplifier 203, in addition to the gain reduction and output mute of the power amplifier 203, the power supply to the power amplifier 203 may be stopped and the audio signal input may be blocked.

  With the home theater device 200 having such an amplifier protection processing function, a dangerous temperature rise of the power amplifier 208 can be prevented in advance, so that the safety and reliability of the entire home theater system can be improved. .

<Operation mode switching function>
The home theater device 200 having the above-described configuration is set to a normal mode in which the amplifier protection processing function is turned on in the default state (operation state at the time of product shipment). When (special code) input is received, the test mode is shifted to the test mode in which the amplifier protection processing function is turned off.

  The operation mode switching function described above is introduced into the home theater device 200 that is actually put on the market, and is programmed as a function of the product version firmware (see FIG. 2) executed by the control unit 203.

  FIG. 3 is a flowchart showing an example of the operation mode switching control, and the execution subject is the control unit 203. First, in step S1, it is determined whether or not a special key has been input. If the determination in step S1 is YES, in step S2, the home theater device 200 operates in a state where the amplifier protection process is turned off (test mode). In the state of shifting to the test mode, the information display unit 201 or a separate monitor OSD display may indicate that the mode is currently shifting to the test mode. On the other hand, when a negative determination is made in step S1, in step S3, the home theater device 200 operates in a state where the amplifier protection processing is turned on (normal mode).

  By adopting such a configuration, unlike the conventional case, it is not necessary to prepare special test firmware (see FIG. 5) just for performing the performance test of the product, so the performance test is easily performed. It becomes possible. Further, by adopting this configuration, the performance of the home theater device 200 that is actually put on the market (the home theater device 200 in which the product version firmware is introduced) can be directly evaluated. It becomes possible to raise.

<Special key (special code)>
As for the special key (special code) for instructing the transition to the test mode, a test remote control used in the factory is prepared separately from the product version remote control that reaches the user's hand. It is desirable to provide a special key (test mode shift key) necessary for shifting to the test mode only (see FIG. 4). By adopting such a configuration, there is no possibility that the user erroneously shifts the home theater device 200 to the test mode. However, the configuration of the present invention is not limited to this, and it may be configured to shift to the test mode by a special operation (such as simultaneous pressing of a plurality of buttons or password input) from the remote controller 210 or the operation unit 205. Absent.

<Other variations>
In the above embodiment, the configuration in which the present invention is applied to the home theater device (= AV player + AV amplifier + speaker) has been described as an example. However, the application target of the present invention is not limited to this. The present invention can be widely applied to audio output devices that amplify audio signals and generate speaker drive signals, such as television broadcast receivers, AV players, AV amplifiers, and speakers with amplifiers. For example, when the present invention is applied to the television broadcast receiving apparatus 100 shown in FIG. 1, the above-described amplifier protection processing function and operation mode switching function may be realized mainly by the control unit 112. .

  The configuration of the present invention can be variously modified within the scope of the present invention in addition to the above embodiment. That is, the above-described embodiment is an example in all respects and should not be considered as limiting, and the technical scope of the present invention is not the description of the above-described embodiment, but the claims. It should be understood that all modifications that come within the meaning and range of equivalents of the claims are included.

  The present invention is a technology that can be widely used for audio output devices that amplify audio signals and generate speaker drive signals, such as home theater devices, television broadcast receivers, AV players, AV amplifiers, and speakers with amplifiers. .

DESCRIPTION OF SYMBOLS 100 Television broadcast receiver 101 Antenna 102 Tuner 103 Demodulation IC
104 Demultiplexer (DEMUX)
105 Video Decoder 106 OSD Processing Unit 107 Video Output Unit 108 Liquid Crystal Panel 109 Audio Decoder 110 Power Amplifier 111 Speaker 112 Control Unit 113 Remote Control Signal Reception Unit 114 Operation Unit 115 HDMI Communication Unit 116 Remote Control 200 Home Theater Device (Audio Output Device)
DESCRIPTION OF SYMBOLS 201 Information display part 202 HDMI communication part 203 Control part 204 Remote control signal receiving part 205 Operation part 206 Sound source part 207 Signal processing part 208 Power amplifier 209 Speaker 210 Remote control

Claims (5)

A power amplifier that amplifies an audio signal and generates a speaker drive signal;
A control unit having an amplifier protection processing function for limiting or stopping the operation of the power amplifier in the event of an abnormality;
An audio output device comprising:
The control unit turns on the amplifier protection processing function in a default state, and turns off the amplifier protection processing function when receiving an input of a special key.   The audio output device according to claim 1, wherein the operation mode switching function according to the input of the special key is programmed as a function of firmware executed by the control unit.   The audio output device according to claim 1, wherein the special key is provided only on a test remote controller.   The control unit monitors a temperature abnormality signal from the power amplifier or a temperature detection signal of a temperature sensor provided in the vicinity of the power amplifier, and determines whether there is a temperature abnormality. The audio | voice output apparatus in any one of Claims 1-3.   In order to limit or stop the operation of the power amplifier in the event of an abnormality, the control unit may reduce the gain of the power amplifier, mute the output of the power amplifier, stop power supply to the power amplifier, and sound to the power amplifier. The sound output device according to claim 1, wherein at least one of signal input blocking is executed.

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