WO2005004148A1

WO2005004148A1 - Sound data reproducing apparatus with integrated audio port/usb port and signal processing method using the same

Info

Publication number: WO2005004148A1
Application number: PCT/KR2004/000083
Authority: WO
Inventors: Younghun Kim
Original assignee: Station Z Co., Ltd
Priority date: 2003-07-03
Filing date: 2004-01-19
Publication date: 2005-01-13
Also published as: KR100466098B1; KR20050005130A

Abstract

A sound data reproducing apparatus including an integrated port able to be selectively coupled with an audio plug and a USB plug, to transmit an audio signal or to receive/transmit USB data, an audio signal switching unit adapted to be switched on/off in accordance with a switching-on/off signal applied thereto, and a microprocessor for receiving USB data from an external medium, and transmitting USB data to the external medium, via the integrated port and signal transmission lines, when the USB plug is coupled to the integrated port, while switching on the audio signal switching unit to externally output an audio signal when the audio plug is coupled to the integrated port. The microprocessor automatically switches the operating mode of the apparatus from a USB communication mode to an audio mode when there is no USB data received/transmitted before a predetermined time elapses in the USB communication mode.

Description

SOUND DATA REPRODUCING APPARATUS WITH INTEGRATED AUDIO PORT/USB PORT AND SIGNAL PROCESSING METHOD USING THE

SAME

Technical Field The present invention relates to a sound data reproducing apparatus with an integrated audio port/USB port, and a signal processing method using the sound data reproducing apparatus. More particularly, the present invention relates to a sound data reproducing apparatus with an integrated audio port/USB port in which an audio mode or USB communication mode is automatically selected in response to insertion of an associated audio plug or USB plug into the integrated audio port/USB port so that the apparatus operates in the selected mode, and a signal processing method using the sound data reproducing apparatus.

Background Art Sound data reproducing devices have recently been developed which have, in addition to a function of simply reproducing music data, a function of downloading music data from a personal computer (PC) or an internet site via a medium such as a transmission cable, and storing the downloaded music data. In particular, MP3 players, which are known as such a sound data reproducing device, are widely used in that they can have a miniature size, as compared to existing reproduction means, for example, CD players, while being capable of storing data in a memory thereof at any time, erasing the stored data at any time, and increasing the capacity of the memory. For such functions thereof, MP3 players are equipped with several ports adapted to enable reproduction of stored sound data, and to receive sound data from an external medium. Such ports include an audio port adapted to be coupled with an audio plug, a USB port adapted to enable USB data reception/transmission with respect to an external medium, and ports for diverse multimedia adapted to provide other functions. Meanwhile, peripheral devices, which transmit data to a PC or receive data from the PC, for example, a digital camera and an MP3 player, mainly use a USB communication system, as a communication system thereof. Accordingly, such a digital camera or MP3 player is essentially provided with a USB port for transmission or reception of data. However, where an audio port and a USB port are provided in a product such as a sound data reproducing device, in order to enable transmission and reception of audio signals or other data, it is impossible to irύni ize the size or volume of the product due to the physical space occupied by the audio port and USB port. Sound data reproducing devices, recently developed and currently commercially available, have a tendency to have a compact and slim structure, in pace with the development of miniature ICs, memory chips, and PCBs, so as to reflect the demand of consumers for miniature products. In the case of sound data reproducing devices using an audio port and a USB port, which have separate structures, respectively, there is a problem in that it is impossible to reduce the size or volume thereof. For example, Korean Utility Model Application No. 1997-35436 discloses a portable MP3 sound data reproducing device, which includes an earphone jack for connection to an earphone adapted to listen to music, and transmitting and receiving jacks for externally transmitting MP3 sound data stored in a sound storage unit, and receiving MP3 sound data from an external device. Although this device is designed to have a compact structure, it must have at least a space for installing the earphone jack and the transmitting and receiving jacks. In other words, in the case of a sound data reproducing device provided with ports for connection thereof with the above mentioned audio jack and USB jack, there is a limitation in reducing the size because it is necessary to provide dual circuit configurations respectively designed for signal processing in association with those ports.

Disclosure of the Invention The present invention has been made in view of the above mentioned problems, and an object of the invention is to provide a sound data reproducing apparatus which includes an integrated audio port/USB port, so that an operation in an audio mode or USB communication mode is automatically carried out in response to insertion of an associated audio plug or USB plug into the integrated audio port/USB port, and to provide a signal processing method using the sound data reproducing apparatus. In accordance with one aspect, the present invention provides a sound data reproducing apparatus comprising: an integrated port able to be selectively coupled with an audio plug and a USB plug, and adapted to transmit an audio signal or to receive/transmit USB data; an audio signal switching unit connected between the integrated port and an audio amplifier, and adapted to be switched on/off in accordance with a switching-on/off signal applied thereto; a microprocessor for receiving USB data transmitted from an external medium or transmitting USB data to the external medium, via the integrated port and signal transmission lines, when the USB plug is coupled to the integrated port, while switching on the audio signal switching unit to externally output an audio signal when the audio plug is coupled to the integrated port, the microprocessor automatically switching an operating mode of the sound reproducing apparatus from a USB communication mode to an audio mode when there is no USB data received or transmitted before a predetermined time elapses in the USB communication mode; and a USB signal processing unit connected between the integrated port and the microprocessor, and adapted to perform reception/transmission of the USB data. In accordance with another aspect, the present invention provides a signal processing method using a sound data reproducing apparatus including a microprocessor, and an integrated port having a port function for transmitting an audio signal when an audio plug is coupled thereto, and a port function for receiving/transmitting USB data when a USB plug is coupled thereto, the signal processing method comprising the steps of: (A) when the USB plug is coupled to the integrated port, receiving USB data from an external medium connected to the USB plug via the integrated port or transmitting USB data to the external medium, via the integrated port; (B), when the audio plug is coupled to the integrated port, externally outputting an audio signal from the apparatus via the integrated port and the audio plug; and (C) when there is no USB data received or transmitted before a predetermined time elapses in a USB communication mode, in which reception/transmission of USB data via the integrated port is carried out, automatically switching, by the microprocessor, an operating mode of the sound reproducing apparatus from the USB communication mode to an audio mode, in which an audio signal from the apparatus is externally outputted. In accordance with the present invention, it is possible to provide a sound data reproducing apparatus such as an MP3 player which is provided with an integrated port designed to be usable for both the audio plug and the USB plug. Accordingly, it is possible to reduce the number of ports, and thus, to minimize the size of the product. Brief Description of the Drawings FIG. 1 is a block diagram illustrating a sound reproducing apparatus with an integrated audio port/USB port in accordance with a preferred embodiment of the present invention; FIG. 2 is a circuit diagram illustrating the circuit configuration of the sound reproducing apparatus shown in FIG. 1; FIG. 3 is a flow chart illustrating signal processing procedures in an audio mode and an USB communication mode through the sound data reproducing apparatus in accordance with the present invention; and FIG. 4 is a block diagram illustrating a sound data reproducing apparatus with an integrated audio port/USB port in accordance with another embodiment of the present invention.

Best Mode for Carrying Out the Invention Now, preferred embodiments of the present invention will be described in detail with reference to the annexed drawings. FIG. 1 is a block diagram illustrating a sound reproducing apparatus with an integrated audio port/USB port in accordance with a preferred embodiment of the present invention. FIG. 2 is a circuit diagram illustrating the circuit configuration of the sound reproducing apparatus shown in FIG. 1. Referring to FIG. 1, the sound reproducing apparatus includes an integrated port 100 adapted to be coupled with an audio plug or a USB plug, and to transmit an audio signal or to receive/transmit USB data via the coupled plug, and an audio signal switching unit 110 connected between the integrated port 100 and an audio amplifier 130, and switched on or off in accordance with a switching-on or off signal applied thereto. The sound reproducing apparatus also includes a microprocessor

140 for receiving USB data transmitted from an external medium, for example, a PC, or transmitting USB data to the external medium, via the integrated port 100, when the USB plug is coupled to the integrated port 100, while switching on the audio signal switching unit 110 to externally output an audio signal via the integrated port 100 when the audio plug is coupled to the integrated port 100.

When there is no USB data received or transmitted before a predetermined time elapses in a USB communication mode, the microprocessor 140 automatically switches the operating mode of the sound reproducing apparatus from the current USB communication mode to an audio mode, in which the audio signal switching unit 110 is switched on. The sound reproducing apparatus further includes a USB signal processing unit 120 connected between the integrated port 100 and the microprocessor 140, and adapted to perform reception/transmission of the USB data. In the illustrated embodiment of the present invention, the integrated port 100 includes four pins, as shown in FIG. 2. That is, the integrated port 100 includes a first pin connected to a USB power terminal USB PWR via a diode Dl and a coil L5, a second pin grounded via coils L6 and L7, and third and fourth pins for transmitting an audio signal in an audio mode while receiving/transmitting USB data in a USB communication mode. The third and fourth pins of the integrated port 100 are connected to the microprocessor 140 via respective signal transmission lines 102a and 102b. Connected to the signal transmission line 102a are a coil L3 for line filtering and a resistor Rl for impedance matching. On the other hand, a coil L4 for line filtering and a resistor R2 for impedance matching are connected to the signal transmission line 102b. An USB control signal line extends from the microprocessor 140 to supply a USB control signal from the microprocessor 140. The USB control signal line is connected to a node between the coil L4 and the resistor R2 via a pull-up resistor R3 of about 1.5KΩ. The audio signal switching unit 110 includes a first NMOS transistor Ql connected at a first terminal thereof to a drive signal output terminal of the microprocessor 140, at a second terminal thereof to the third pin of the integrated port 100 via a coil Ll for noise removal, and at a third terminal thereof to a first audio output terminal A of the audio amplifier 130. The audio signal switching unit 110 also includes a second NMOS transistor Q2 connected at a first terminal thereof to the drive signal output terminal of the microprocessor 140, at a second terminal thereof to the third pin of the integrated port 100 via a coil L2 for noise removal, and at a third terminal thereof to a second audio output terminal B of the audio amplifier 130. A coupling capacitor may be connected between the third terminal of the first NMOS transistor Ql and the first audio output terminal A of the audio amplifier 130. Similarly, a coupling capacitor may be connected between the third terminal of the second NMOS transistor Q2 and the second audio output terminal B of the audio amplifier 130. Preferably, the coil Ll is connected at one end thereof between the third pin of the integrated port 100 and the coil L3, and at the other end thereof to the second terminal of the first NMOS transistor Ql. Preferably, the coil L2 is connected at one end thereof between the fourth pin of the integrated port 100 and the coil L4, and at the other end thereof to the second terminal of the second NMOS transistor Q2. Now, operation of the sound data reproducing apparatus with the integrated audio port/USB port according to the illustrated embodiment of the present invention will be described with reference to a flow chart of Fig. 3. When an audio plug or USB plug is connected to the integrated port 100 under the condition in which both the audio mode and the USB communication mode are initially in an OFF state thereof, the associated audio mode or USB communication mode is automatically set. This operation will be described hereinafter in association with respective modes. First, the operation associated with the USB communication mode will be described. The following description will be given in conjunction with only the transmission of USB data from an external medium to the sound data reproducing apparatus because the reception and transmission of USB data are carried out in the same manner. When a USB plug is coupled to the integrated port 100 under the condition in which both the audio mode and the USB communication mode are in an OFF state thereof (Steps 200 and 202), power from an external medium, for example, a

PC, is applied to the USB power terminal USB PWR via an adapter or the like, and then supplied to the microprocessor 140 ("YES" at Step 204). Alternatively, it may be possible to supply power from a battery equipped in the sound data reproducing apparatus to the microprocessor 140 when the USB plug is coupled to the integrated port 100. Then, the microprocessor 140 makes a transition of the USB control signal supply line from a low level to a high level. Simultaneously, the node between the pull-up resistor R3 on the USB control signal supply line and the signal transmission line 102b is changed to a pull-up state by the pull-up resistor R3 (Step 206). Although both the signal transmission lines 102a and 102b are initially in a

"0" level state, that is, a USB reset state, only the signal transmission line 102b is changed to a high level, that is, a full speed connection state, in response to the transition of the USB control signal supply line to a high level. In this state, the external medium, for example, a PC, connected to the USB plug, and thus, to the integrated port, can transmit sync data to the microprocessor 140 via the signal transmission lines 102a and 102b at intervals of a predetermined time, for example, 1/60 sec, at a predetermined frequency of, for example, 12MHz. In response to the sync data, the microprocessor 140 transmits an acknowledgement signal to the external medium via the USB signal processing unit 120 and integrated port 100. When the sync data from the external medium is transmitted to the microprocessor 140 in the above described manner, the microprocessor 140 determines that the external medium desires USB communication therewith. Based on this determination, the microprocessor 140 maintains the audio signal switching unit 110 in its OFF state. Following the transmission of the sync data, the external medium outputs USB data which is, in turn, transmitted to the microprocessor 140 via the third and fourth pins of the integrated port 100 and signal transmission lines 102a and 102b. Thus, USB data communication is carried out between the external medium and the microprocessor 140 ("YES" at Step 208). During this USB data communication, that is, in the USB communication mode, the microprocessor 140 maintains both the NMOS transistors Ql and Q2 of the audio signal switching unit 110 in their OFF state (Step 210). In this state, data transmission can be carried out between the external medium and the microprocessor 140 through the USB communication system (Step 212). The data transmission through the USB communication system means that USB data is transmitted in a state in which respective levels of the signal transmission lines 102a and 102b are changed at intervals of a certain time while being reverse to each other. That is, when the level of the signal transmission line 102a is changed to a high level, the level of the signal transmission line 102b is changed to a low level, whereas when the level of the signal transmission line 102a is changed to a low level, the level of the signal transmission line 102b is changed to a high level. The reason for such a periodic level change is to make the microprocessor 140 recognize the fact that the external medium is transmitting USB data. When the transmission of USB data is completed during the USB data communication ("YES" at Step 214, and Step 216), the user separates the USB plug from the integrated port 100 (Step 218). Thus, the microprocessor 140 is returned to a standby state thereof. However, when no USB data is transmitted from the external medium to the microprocessor 140 for a predetermined time under the condition in which the USB data has incompletely been transmitted ("YES" at Step 214), the microprocessor 140 releases the current USB communication mode, and automatically activates the audio mode. Of course, the operation in the audio mode is also carried out when the audio plug is connected to the integrated port 100, in place of the USB plug (Step 220). That is, the microprocessor 140 generates a high-level drive signal (Step 222), and applies the drive signal to the audio signal switching unit 110. Based on this high-level drive signal, the NMOS transistors Ql and Q2 turn on (Step 224). In the ON states of the NMOS transistors Ql and Q2, the audio line connected between the integrated port 100 and the audio amplifier 130 is activated (Step 226), so that an audio signal of a certain frequency is externally outputted via the third and fourth pins of the integrated port 100 in accordance with an operation of the audio signal switching unit 110, after being amplified by the audio amplifier 130 (Step 228). Of course, during the operation in the audio mode, the USB communication mode is maintained in an inactive state. After the audio signal is completely outputted in the above described manner, the user separates the audio plug from the integrated port 100. Thus, the microprocessor 140 is returned to the standby state thereof. FIG. 4 is a block diagram illustrating a sound data reproducing apparatus with an integrated audio port/USB port in accordance with another embodiment of the present invention. This embodiment is identical to the above described embodiment in terms of configuration and function, except that the USB signal processing unit 120 further includes a regulator serving as a stabilizing circuit. Accordingly, no description will be given of the identical configuration and function. The regulator is connected to the USB power terminal USB PWR and to a front end of the resistor R2 coupled to the fourth pin of the integrated port 100, in order to supply constant voltage and current irrespective of a variation in input/output load. Of course, the regulator has a configuration adapted to receive the USB control signal. In accordance with the provision of such a regulator, it is possible to achieve an improvement in stability while reducing the failure of elements used in the sound data reproducing apparatus. Industrial Applicability As apparent from the above description, in accordance with the sound data reproducing apparatus with the integrated audio port/USB port and the signal processing method using the apparatus, an audio mode or USB communication mode is automatically selected in response to insertion of an associated audio plug or USB plug into the integrated audio port/USB port so that the apparatus operates in the selected mode. Accordingly, it is possible to reduce the number of ports, and thus, to minimize the size of the product, as compared to conventional cases. Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A sound data reproducing apparatus comprising: an integrated port able to be selectively coupled with an audio plug and a USB plug, and adapted to transmit an audio signal or to receive/transmit USB data; an audio signal switching unit connected between the integrated port and an audio amplifier, and adapted to be switched on/off in accordance with a switching- on/off signal applied thereto; a microprocessor for receiving USB data transmitted from an external medium via the integrated port and signal transmission lines or transmitting USB data to the external medium, via the integrated port and the signal transmission lines, when the USB plug is coupled to the integrated port, while switching on the audio signal switching unit to externally output an audio signal when the audio plug is coupled to the integrated port, the microprocessor automatically switching an operating mode of the sound reproducing apparatus from a USB communication mode to an audio mode when there is no USB data received or transmitted before a predetermined time elapses in the USB communication mode; and a USB signal processing unit connected between the integrated port and the microprocessor, and adapted to perform reception/transmission of the USB data.

2. The sound data reproducing apparatus according to claim 1, wherein the audio signal switching unit comprises a plurality of switching elements.

3. The sound data reproducing apparatus according to claim 2, wherein each of the switching elements comprises an NMOS transistor.

4. The sound data reproducing apparatus according to claim 1, wherein the integrated port includes a first pin connected to a USB power terminal, a second pin connected to a ground terminal, and third and fourth pins respectively connected to the signal transmission lines.

5. The sound data reproducing apparatus according to claim 1, wherein the USB signal processing unit includes a regulator for receiving a USB control signal from the microprocessor.

6. The sound data reproducing apparatus according to claim 1 or 5, wherein the microprocessor changes a USB control signal supply line, connected thereto, to a high level thereof when the USB plug is coupled to the integrated port, to pull up a node between a pull-up resistor installed on the USB control signal supply line and one of the signal transmission lines, thereby enabling transmission/reception of USB data.

1: A signal processing method using a sound data reproducing apparatus including a microprocessor, and an integrated port having a port function for transmitting an audio signal when an audio plug is coupled thereto, and a port function for receiving/transmitting USB data when a USB plug is coupled thereto, the signal processing method comprising the steps of: (A) when the USB plug is coupled to the integrated port, receiving USB data from an external medium connected to the USB plug via the integrated port or transmitting USB data to the external medium via the integrated port; (B) when the audio plug is coupled to the integrated port, externally outputting an audio signal from the apparatus via the integrated port and the audio plug; and (C) when there is no USB data received or transmitted before a predetermined time elapses in a USB communication mode, in which reception/transmission of USB data via the integrated port is carried out, automatically switching, by the microprocessor, an operating mode of the sound reproducing apparatus from the USB coπmiunication mode to an audio mode, in which an audio signal from the apparatus is externally outputted.

8. The signal processing method according to claim 7, wherein the audio mode is maintained in an inactive state during execution of the step (A), under control of the microprocessor.

9. The signal processing method according to claim 7, wherein the USB communication mode is maintained in an inactive state during execution of the step (B) under control of the microprocessor.