KR20070106083A - Audio output apparatus capable playing digital data - Google Patents

Abstract

An audio output device playing digital sound data is provided to play MP3(MPEG Audio Layer-3) sound files stored in an external storage device by including an external memory access unit such as a USB(Universe Serial Bus) port. An audio output device playing digital sound data includes an operating unit(140) receiving an operation signal from a user; an analog input unit(100) receiving an analog sound source signal; an external memory access unit(110) receiving digital sound data stored in an external memory; a signal processing unit(120) decoding MP3 sound files inputted to the external memory access unit and converting the decoded digital signal into an analog signal; a control unit(130) selecting one of the analog signals outputted from the analog input unit and the signal processing unit according to the operation signal input through the operating unit and then outputting the selected signal; an amplifying unit(150) amplifying the analog signal outputted from the analog input unit or the signal processing unit and outputting the amplified signal; and a speaker(160) outputting the signal amplified in the amplifying unit.

Description

Audio output device that can play digital sound sources {Audio output Apparatus Capable Playing Digital Data}

1 is a block diagram schematically showing the configuration of an audio output apparatus according to an embodiment of the present invention;

2 is a block diagram schematically showing the configuration of an audio output device equipped with two speaker devices according to the present invention;

3 is a block diagram schematically illustrating a configuration of an audio output apparatus according to another embodiment of the present invention;

4 is a diagram illustrating an audio output device including a first speaker device and a second speaker device in one enclosure according to a preferred embodiment of the present invention;

5 is a diagram illustrating an audio output device in which a first speaker device and a second speaker device are implemented in separate enclosures according to an exemplary embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

100: analog input unit 110: external memory access unit

120: signal processing unit 130: control unit

140: operation unit 150: amplification unit

160: speaker 200: first speaker device

202, signal detection unit 250: second speaker device

300: file conversion unit 310: display unit

400: circuit portion 410: digital part

420: analog part 430: glass fiber

440: shielding material

The present invention relates to an audio output device, and more particularly, to an audio output device capable of reproducing a digital sound source by itself.

Unlike the conventional method in which a single item performs only one function, development of electronic devices that can be utilized in a multifunctional manner is increasingly active according to the needs of consumers who simultaneously pursue simplicity and practicality. For example, it is no longer unusual to have a digital camera function or an MP3 (MPEG Audio Layer-3) player function installed in a mobile communication terminal that merely performed a call function.

In addition, with the development of flash memory that can freely read and write files, it is common for users to carry and use a portable external memory. The external memory can easily store a large file, it is easy to carry with a small light weight, and can freely play the stored media files if there is a playback device. Such external memory devices include, for example, USB memory sticks and SD / MMC cards that can store compressed audio files by mounting a memory device inside.

In addition, as the functions of a personal computer (PC) are diversified, not only are they able to listen to music that they want to listen to through the computer, but also their use as a home theater is increasing. Therefore, the speaker, which is only an auxiliary device of the computer, needs to be improved in order to realize a sound close to natural sound, instead of merely producing a mechanical sound. In fact, users want to enjoy music with better sound quality through personal computers, and enjoy various sounds realistically as the use of media playback devices such as movie watching and video files through personal computers increases.

SUMMARY OF THE INVENTION The present invention is derived from such a background, and an object of the present invention is to provide an audio output device for a computer that can be used as a normal speaker connected to a PC and play MP3 files stored in a portable storage device at high quality.

Furthermore, an object of the present invention is to switch to automatically output an analog signal input from a PC even during digital sound source reproduction.

 In addition, an object of the present invention is to improve the performance of the sound quality by improving the characteristics of the internal circuit and reducing noise.

Audio output device according to an aspect of the present invention for achieving the above object is used as a speaker of a conventional PC having an analog input unit and at the same time having an external memory access unit such as a USB port MP3 sound source files stored in an external storage device It is characterized in that to play by itself.

According to the present invention according to this aspect of the present invention, even if the output of the analog sound signal output from the personal computer to a single speaker and at the same time is not equipped with a special playback device is connected only to the external memory to the speaker device according to the invention MP3 files stored in the memory can be enjoyed at the same time, so that one speaker can perform various functions.

According to another aspect of the present invention, as implemented by the first speaker device and the second speaker device has an effect that can provide stereo sound.

According to an additional aspect of the present invention, an audio output apparatus detects an analog sound source signal input from an analog input unit and, when a signal is detected, preferentially selects and outputs an analog sound source signal input to the analog input unit. Accordingly, it is possible to preferentially output the sound source file on the PC requiring the active operation of the user, and provides the convenience of automatically switching the signal to be output between the two signals input to the speaker even if the user does not operate separately.

Furthermore, the audio output device according to the present invention is characterized in that each device is classified into a digital part and an analog part and mounted on a shielded board according to the form of a signal processed therein. Accordingly, there is an effect that can improve the sound quality performance by improving the circuit characteristics by minimizing the influence of the noise signal generated during the analog signal processing.

The foregoing and additional aspects of the present invention are described in detail below to enable those skilled in the art to readily understand and reproduce through the embodiments described with reference to the accompanying drawings.

1 is a block diagram schematically illustrating a configuration of an audio output apparatus according to an exemplary embodiment of the present invention. As shown, the audio output device according to the present invention includes an operation unit 140 for receiving an operation signal from a user, an analog input unit 100 for receiving an analog sound source signal, and an external memory for receiving digital sound source data stored in an external memory. An operation inputted through the access unit 110, a signal processor 120 for decoding the MP3 sound source file input to the external memory access unit 110, and converting the decoded digital signal into an analog signal, and an operation unit 140. Amplifying an analog signal output from the control unit 130 and the analog input unit 100 or the signal processing unit 120 to select and output one of the analog signal output from the analog input unit 100 or the signal processing unit 120 according to the signal And an amplifier 150 for outputting the signal, and a speaker 160 for outputting the signal amplified by the amplifier 150.

The operation unit 140 generates corresponding key data of a key input according to a user's input. The operation unit 140 may be implemented in a configuration mounted on a digital sound source playback apparatus such as a conventional MP3 player, CDP. In the present embodiment, the operation unit 140 includes function buttons such as power on / off, volume level, previous track, next track, fast playback, etc. according to the function of reproducing the sound source data. However, the present invention is not limited thereto and may be implemented to operate any function required for digital sound source reproduction. In addition, it can be implemented in the form of a button press and can be implemented to perform functions such as volume control and song search in the form of a touch screen or jog dial.

In addition, the display unit 310 may identify a playback state, a volume state, and a digital audio file stored in an external memory connected to the external memory access unit 110 through the display unit 310. Accordingly, the user can play music selected by the user from among files stored in the external memory.

The analog input unit 100 is implemented as an external input terminal (AUX: Auxilliary). In the present embodiment, the analog input unit 100 receives an analog sound source signal from a personal computer (PC).

The external memory access unit 110 accesses the external memory and receives a compressed digital file stored in the memory. In one embodiment, the external memory access unit 110 receives an MP3 (MPEG Audio Layer-3) sound source file stored in an external memory. In the present embodiment, the external memory access unit 110 may be implemented as a slot that can be connected to a universal serial bus port (USB port) or an SD / MMC card. When the external memory access unit 110 is a USB port, the external memory access unit 110 is implemented as a USB host. When the USB slave is recognized from the external memory, the external memory access unit 110 may access the USB memory and read the stored file.

Secure Digital Card is a stamp-sized flash memory card. SD cards have a high storage capacity and can be used for digital products such as personal digital assistants and digital media players. It has the advantage of fast data processing and password setting for data complement. Multi-media cards (MMCs) are called multimedia cards and are very small external flash memory suitable for portable devices. As portable devices become smaller and lighter, the range of use is increasing rapidly.

In the present embodiment, the external memory access unit 110 may receive digital audio files stored in the external memory as described above. The external memory access unit 110 according to the present invention may be embodied in any configuration capable of receiving a digital audio file that can be reproduced by including the obvious modifications.

The signal processor 120 may be implemented with a conventional codec. The codec decodes the digital data from the compressed file input from the external memory access unit 110. In the present embodiment, the digital audio files input from the external memory access unit 110 may be files of various types compressed in the manner of WMA, MP3, AC3, or the like. However, it is preferable that the compression form is performed by the compression method of the most common sound source. The signal processor 120 converts the decoded digital data into an analog signal and outputs the analog signal.

The controller 130 may be implemented with a conventional microprocessor chip for controlling the overall operation of the audio output device and a program mounted thereon. In the present exemplary embodiment, the controller 130 outputs one of an analog signal input from the analog input unit 100 or an analog signal processed and output by the signal processor 120 according to a control signal input from the operation unit 140. To control. In addition, it is obvious to be implemented to control the playback state of the MP3 file input through the external memory access unit 110 according to the control signal input from the operation unit 140.

For example, if there is a command for playing the next track in the operation unit 140, the controller 130 receives the file corresponding to the next track among the files input through the external memory access unit 110 and processes the signal processor 120. ).

The amplifier 150 amplifies the analog signal according to the volume control signal input from the controller 130. The amplifier 150 amplifies and outputs an input analog signal, and includes a preamplifier and a power amplifier. The pre-amp receives the analog signal, amplifies it, sends the signal to the power amplifier, and the power amplifier amplifies the signal again to drive the speaker 160. In the present embodiment, the amplifier 150 includes an input buffer for impedance matching including a DC servo for removing the DC offset voltage from the analog signal selected and output from the controller 130. The amplifier 150 amplifies and outputs an analog signal input according to the volume control signal input from the manipulation unit 140.

The speaker 160 outputs the signal amplified by the amplifier 150 as an audible sound. Speaker 160 is a configuration known as an electromechanical transducer that converts electrical energy into mechanical vibrations.

2 is a block diagram schematically showing the configuration of an audio output device equipped with two speaker devices according to the present invention.

According to a characteristic aspect, an audio output apparatus according to the present invention includes a second amplifier 252 and a second amplifier 252 for amplifying and outputting an analog signal output from the analog input unit 100 or the signal processor 120. The second speaker 254 for outputting the amplified signal further comprises.

The signal processor 120 includes a decoder and a signal converter 224 for converting a digital signal into an analog signal. The decoding unit may be implemented as a decoder for decompressing a conventional sound source file in a known configuration. In the present embodiment, the decoding unit decompresses various types of files compressed in the manner of WMA, MP3, AC3, etc. input from the external memory access unit 110.

The signal converter 224 filters and outputs digital audio data input from the decoder into an audio frequency band. In one embodiment, the signal converter 224 converts the decoded digital data input from the decoder into an I2S signal, and converts the I2S signal into an analog signal to output a signal within an audible frequency band.

Inter-IC Sound (I2S) is one of the audio transmission methods. I2S processes audio data separately from the clock signal. Thus, errors related to time that cause jitter can be prevented.

According to another exemplary embodiment of the present invention, the signal processor 120 may include a hi-fi processor 222 for hi-fi processing the digital sound source data flowing therein.

The hi-fi processing unit 222 processes the signal-to-noise ratio (SNR) to a Hi-Fi level of 100 dB or more in filtering the I2S signal into the audible frequency band. In the present embodiment, the hi-fi processing unit 222 includes a jitter attenuation circuit and a frequency converter circuit for attenuating jitter. In one example, the frequency conversion circuit increases the sample frequency of the I2S signal to 96 Kbps or 192 Kbps. By increasing the sample frequency, the sampling interval can be narrowed to improve the continuity of the analog sound source signal, thereby improving the sound quality.

The hi-fi processing unit 222 may pass the input I2S signal through the jitter attenuation circuit, and then increase the sample frequency to convert the analog signal into an analog signal to provide a high-quality hi-fi speaker. Since the hi-fi processing technology itself is a known matter, a detailed description thereof will be omitted.

The second amplifier 252 and the second speaker 254 may be implemented in the same configuration as the amplifier 150 and the speaker 160 described above.

In the present embodiment, it may be implemented as two speakers, and in this case, it may be divided into a first speaker device 200 and a second speaker device 250 for outputting a sound source. In the present exemplary embodiment, the second speaker device 250 amplifies and outputs an analog signal input from the first speaker device 200.

The first speaker device 200 and the second speaker device 250 may be implemented as one enclosure or two enclosures. 4 is a block diagram illustrating an audio output device including a first speaker device and a second speaker device in one enclosure according to an exemplary embodiment of the present invention. 5 is a block diagram illustrating an audio output device in which a first speaker device and a second speaker device are implemented in separate enclosures according to an exemplary embodiment of the present invention.

As such, as the sound source is output through the two speaker devices, the stereo sound may be provided.

The audio output apparatus according to the aspect of the present invention further includes a signal detector 202 for detecting an analog sound source signal input from the analog input unit 100, wherein the controller 130 detects a signal at the signal detector 202. When the analog sound source signal input to the analog input unit 100 is preferentially selected.

The signal detector 202 may be implemented as a detection circuit using a DSP (Digital Signal Processing) chip or an OP amplifier. In this embodiment, the signal detector 202 detects the presence / absence of an analog signal input from the analog input unit 100. In this embodiment, the signal detection unit 202 includes a DC blocking circuit unit for blocking an undesired DC voltage among input signals, an amplifying circuit, a rectifying circuit for obtaining a DC signal from an AC signal, and a smoothing circuit. In addition, a voltage comparator capable of detecting the presence / absence of a signal input from the analog input unit 100 by a predetermined comparison voltage V _ref supplied from a power supply voltage. The circuits included in the signal detector 202 may have a known configuration. The signal detector 202 according to the present exemplary embodiment outputs a high value when there is an analog signal input to the analog input unit 100, and outputs a low value when no signal is input.

The controller 130 selects an analog signal to be output to the speaker 160 according to the signal detection result from the signal detector 202. The controller 130 may select one of the analog signal input from the analog input unit 100 and the analog signal converted from the digital data through the signal processor 120 according to the presence / absence of the analog signal input from the signal detector 202. Select and print. In the present embodiment, even when the digital data input to the external memory access unit 110 is reproduced and output, if the analog signal input from the analog input unit 100 connected to the PC is detected, the analog input through the analog input unit 100 It is implemented to output the signal preferentially.

In fact, when a user uses a PC, playing a music file or other audio file requires an active action such as a 'click'. That is, the analog signal output from the PC has already been selected by the user. Therefore, even when the audio output device according to the present invention is in the state of reproducing digital sound source data stored in the external memory, the signal is preferentially outputted when the user plays music or audio file that the user wants to listen to while using the computer. According to this aspect, according to the present invention, there is an effect of automatically switching the output signal.

3 is a block diagram schematically illustrating a configuration of an audio output apparatus according to another embodiment of the present invention.

The audio output device according to the present invention includes a recording function button that the operation unit 140 receives a recording function signal, the audio output device converts a sound source input from the analog input unit into an MP3 file when the recording function signal is received; The apparatus may further include a file converter 300 that stores the converted MP3 file in an external memory mounted in the external memory access unit.

The file converter 300 may be implemented with a codec including an encoder. In the present exemplary embodiment, the file converter 300 converts an analog signal input from the analog input unit 100 into a digital signal and compresses the analog signal into a form suitable for storage in an external memory.

Accordingly, the audio output device according to the present invention not only plays a file stored in an external memory, but also converts an analog signal input through a PC or an external microphone into a digital signal, compresses it, and stores it in the external memory. There is a possible effect.

According to a further aspect of the present invention as shown in Figure 4, the audio output device according to the present invention is divided into the speaker (160, 254) and the circuit portion 400 other than the speaker, the inner wall of the circuit portion 400 It characterized in that the shielding material 440 is applied to. In addition, the circuit unit 400 is characterized in that the analog part and the digital part are mounted separately according to the type of signal processed in each device, and comprises a glass fiber 430 inside the shielded circuit unit 400.

As shown, the interior of the audio output device is designed to divide the speaker (160, 254) that generates the sound through the resonance and the remaining circuit portion 400 to block the noise effect generated by the resonance effect.

 In addition to the audio output device according to the present invention, electrical noise generated by peripheral electronic devices may enter the audio output device on a power line. Such noise, for example, electromagnetic interference or electromagnetic interference such as EMI (Electro Magnetic Interference) is generated in the digital circuit. Digital noise may flow into the preamplifier, some of which may leak into a capacitor in the power amplifier power supply, resulting in a decrease in musical performance. In addition, the performance of the audio device may be degraded by electromagnetic compatibility or electronic compatibility in an electronic environment problem such as EMC (Electro Magnetic Compatibility).

In order to prevent such performance degradation, a space may be filled with the glass fiber 430 inside the audio output device, and a shielding material 440 may be applied to the inner wall to prevent the interference as described above.

According to an additional aspect of the present invention, the audio output device according to the present invention separates the digital element and the analog element according to the form of the signal processed in the circuit and sets the boards of the digital part 410 and the analog part 420 separately. In addition, it is possible to construct a board circuit that minimizes electrical interference between circuits. In the present embodiment, it is particularly preferable that the amplifier 150 and the second amplifier 252 sensitive to the influence of noise are shielded by separate boards. Accordingly, there is an effect that can improve the sound quality performance by improving the circuit characteristics by minimizing the influence of the noise signal generated during the analog signal processing.

As described in detail above, according to the present invention, an analog input unit is used as a speaker of a conventional PC and an external memory access unit, such as a USB port, is used to play an MP3 sound file stored in an external storage device by itself. Outputting analog signals on a computer with a single speaker and at the same time, even if there is no special playback device, by connecting external memory, you can enjoy MP3 files stored in the memory at the same time. have.

Furthermore, according to the present invention, it is possible to provide stereo sound as implemented by the first speaker device and the second speaker device, increase the sampling frequency for the digital sound source data to be reproduced, and pass the jitter attenuation circuit and then convert it into an analog signal. As a result, the playback sound quality can be improved to provide a high-fidelity hi-fi speaker.

In addition, according to the present invention, when the analog sound source signal input from the analog input unit is detected and a signal is detected, the analog sound source signal input to the analog input unit is preferentially selected and outputted so that the user inputs two speakers without any separate operation. Provides the convenience of automatically switching the signal to be output among the signals.

In addition, the audio output device according to the present invention minimizes the influence of noise signals generated during analog signal processing by dividing each element into a digital part and an analog part according to the shape of a signal processed therein, and mounting the device on a shielded board. By improving the circuit characteristics, there is an effect that can improve the sound quality performance.

The present invention has been described above with reference to preferred embodiments, but is not limited thereto, and is interpreted by the appended claims, which are intended to cover many modifications that will be apparent to those skilled in the art without departing from the scope of the present invention. Should be done.

Claims (7)

An operation unit receiving an operation signal from a user; An analog input unit for receiving an analog sound signal; An external memory access unit for receiving digital sound source data stored in an external memory; A signal processor which decodes an MP3 sound source file input to the external memory access unit and converts the decoded digital signal into an analog signal; A control unit for selecting and outputting one of the analog signals output from the analog input unit or the signal processing unit according to an operation signal input through the operation unit; An amplifier for amplifying and outputting an analog signal output from the analog input unit or the signal processor; A speaker for outputting the signal amplified by the amplifier; Audio output device capable of playing the digital sound source, characterized in that it comprises a. The device of claim 1, wherein the audio output device is: A second amplifier for amplifying and outputting an analog signal output from the analog input unit or the signal processor; A second speaker for outputting a signal amplified by the second amplifier; Audio output device capable of playing the digital sound source further comprises a. The device of claim 1 or 2, wherein the audio output device is: And a signal detector for detecting an analog sound source signal input from the analog input unit. The control unit: When the signal is detected by the signal detection unit, the audio output device capable of reproducing the digital sound source, characterized in that to preferentially select the analog sound signal input to the analog input unit. The method of claim 3, wherein the signal processing unit: And a hi-fi processing unit for hi-fi processing the incoming digital sound source data. The method of claim 3, wherein the operation unit: It includes a recording function button to receive a recording function signal, The speaker device: A file conversion unit converting a sound source input from the analog input unit into an MP3 file when the recording function signal is received and storing the converted MP3 file in an external memory mounted to the external memory access unit; Audio output device capable of playing the digital sound source further comprises. The device of claim 4 or 5, wherein the audio output device is: Its interior is divided into speakers and circuits other than speakers, An audio output apparatus capable of reproducing a digital sound source, wherein a shielding material is coated on an inner wall of the circuit unit. The method of claim 6, wherein the circuit portion: Depending on the type of signal processed in each device, it is divided into analog parts and digital parts, An audio output apparatus for reproducing a digital sound source, characterized in that it comprises a glass fiber in the space inside the shielded circuit portion.

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