JP2009194890A - Mobile terminal, audio apparatus discrimination method, audio apparatus discrimination program, and program recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable terminal capable of automatically detecting the kinds of a plurality of kinds of audio apparatuses to be connected to a single jack interface, and performing changeover into connection to an audio circuit or into an audio operation, which are suitable for the connected audio apparatus. <P>SOLUTION: The mobile terminal includes at least: an R→V converting circuit 20 for converting the impedances of respective channels, i.e., LEFT, RIGHT and MIDDLE in the audio apparatus connected to the jack interface 10 into voltage values; and an A/D converter 30 for outputting results after comparing the respective voltage values with a predetermined voltage threshold. The kind of the connected audio apparatus is discriminated by the combination of comparison results between the respective voltage values of the respective channels LEFT, RIGHT and MIDDLE and the voltage threshold. A connection state with an audio CODEC 50 and the input/output level of an audio signal are changed-over based on the discrimination result. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a portable terminal, an audio device identification method, an audio device identification program, and a program recording medium, and more particularly to a portable terminal having an audio function.

Conventionally, a small portable terminal (for example, a notebook PC, a PDA, etc.) as disclosed in Japanese Patent Application Laid-Open No. 2006-21435 of Patent Document 1 has a jack interface for connecting external headphones or a microphone. Most are provided.
JP 2006-21435 A (page 6-8)

  In the case of a notebook PC, since a certain physical size is allowed, it is possible to mount a plurality of jack interfaces and circuits corresponding to plugs of various audio devices such as headphones, microphones, and line-ins. It is.

  However, in a PDA or the like, which is a smaller portable terminal, it is physically strict to install a plurality of jack interfaces, and in general, only a single function and a single interface such as a headphone or an earphone microphone are installed. However, there is a problem that the audio function cannot be sufficiently provided.

  On the other hand, with the advancement of multimedia functions and solution systems, there is an increasing demand for adapting to various audio devices such as headphones, earphone microphones, stereo microphones, etc., even with small portable terminals such as PDAs. In addition, while maintaining the miniaturization of mobile terminals, setting the appropriate speaker volume and microphone gain for the type of multi-functional jack interface, its circuit, and connected audio device compatible with various audio devices It has been a challenge to provide a software that performs the above and to cope with a 2-input microphone compatible headset for the purpose of removing ambient noise.

  In addition, in order to support microphones and speakers with various characteristics, not only existing audio devices, but also future audio devices can be set only with software (SW) settings or by simple modifications. The challenge is to make this possible.

  In order to solve these problems, the present invention automatically detects a plurality of types of audio devices such as headphones, earphone microphones, and stereo microphones connected to a single jack interface, and sets the types of connected audio devices. An object of the present invention is to provide a portable terminal, an audio device determination method, an audio device determination program, and a program recording medium that can be switched to connection or operation to a suitable audio circuit.

  In addition, in order to support microphones and speakers having various characteristics, an arbitrary threshold can be set by software (SW) according to the impedance characteristics of the connected input device (microphone) or output device (speaker). An object of the present invention is to provide a portable terminal, an audio device identification method, an audio device identification program, and a program recording medium.

  In order to solve the above-described problems, the mobile terminal, the audio device identification method, the audio device identification program, and the program recording medium according to the present invention employ the following characteristic configurations.

  (1) In a portable terminal having one 4-pole jack interface capable of connecting a plurality of types of audio equipment, each of the LEFT channel, RIGHT channel, and MIDDLE channel of the audio equipment connected to the jack interface An audio device discriminating unit that discriminates the type of the connected audio device by identifying the magnitude of the impedance is provided, and the audio signal is converted based on the type of the audio device discriminated by the audio device discriminating unit. A portable terminal that switches at least a connection state between an audio CODEC to be performed and the jack interface and an input / output level of an audio signal.

  According to the portable terminal, audio device identification method, audio device identification program, and program recording medium of the present invention, the following effects can be obtained.

  Only one jack interface, monaural earphone (2-pole jack), stereo headphones (3-pole jack), earphone microphone (3-pole jack), stereo microphone (3-pole jack), 2-input microphone compatible headset (4-pole jack) ) Or multiple types of audio equipment such as a stereo earphone microphone (4-pole jack), 2-pole plug, 3-pole plug, and 4-pole plug. A variety of audio functions can be sufficiently provided without deteriorating the physical size.

  Also, since it is possible to cope with only software (SW) settings, it is possible to support more audio devices not only for existing devices but also for future devices.

  In addition, since the type determination after connecting the audio device and the setting suitable for each audio device are automatically performed by software control, there is no need for the user to perform the switching operation, and an error in the jack interface to be applied. This also helps prevent insertion and helps reduce the failure rate.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a mobile terminal, an audio device identification method, an audio device identification program, and a program recording medium according to the present invention will be described with reference to the accompanying drawings. In the following description, a portable terminal and audio device determination method according to the present invention will be described. However, the audio device determination method may be implemented as an audio device determination program executable by a computer, or Needless to say, the audio device determination program may be recorded on a computer-readable recording medium.

(Features of the present invention)
Prior to the description of the embodiments of the present invention, an outline of the features of the present invention will be described first. The present invention is a portable terminal provided with only one 4-pole jack interface as an interface for connecting a plurality of types of audio equipment such as headphones, earphone microphones, stereo microphones, etc. connected to an audio jack interface. Automatically identifies the type of audio device connected to the software, and automatically switches the software (SW: Software) operation to connect to an input / output circuit suitable for the connected audio device and set the input / output signal level. The main feature is to provide a portable terminal that can be used in the future.

  Alternatively, a detection signal of a 4-pole jack interface having a function of arbitrarily setting a threshold value of an audio jack automatic discrimination detection circuit for discriminating a connected audio device by software (SW) control and connected to the audio device The comparison circuit for comparing the value with the threshold value is realized by hardware (HW: Hardware), thereby enabling efficient parallel operation of software processing (SW processing) and improving responsiveness.

  In other words, in the present invention, each audio device such as a headphone, an earphone microphone, and a stereo microphone connected to one jack interface mounted on a portable terminal is automatically determined based on a setting value such as software, and the determination According to the result, the audio input / output circuit is switched and the input / output signal level is set to an appropriate value, thereby making it possible to adapt to a plurality of types of audio devices with one jack interface.

  Here, in order to automatically determine each audio device connected to the jack interface, the impedance between the LEFT channel-GND, the RIGHT channel-GND, and the MIDDLE channel-GND wired to the plug of each audio device Using the characteristics, each impedance is converted to a voltage value, the voltage values converted as 1ch, 2ch, and 3ch of the A / D converter provided inside the portable terminal are read, and any value is controlled by software (SW) control Is compared with a voltage threshold value (reference voltage Ref) set to. It is possible to set different threshold values for the 1ch, 2ch, and 3ch as the voltage threshold (reference voltage), and the first reference voltage, the second reference voltage, and the third threshold set for each channel. The reference voltage and the converted voltage values of the LEFT channel, RIGHT channel, and MIDDLE channel are respectively compared by a comparison process on software (SW) or a comparison circuit (comparator) on hardware (HW). Corresponding to each channel, a 3-bit status signal is generated as a comparison result.

  For each of the LEFT channel, RIGHT channel, and MIDDLE channel of the connected audio device, generally, the impedance of the input device (microphone) is as large as 1 KΩ or more, and the impedance of the output device (speaker) is 8Ω to Since it is as small as about 300Ω, it differs depending on whether the output of the comparison result is an input device (microphone) or an output device (speaker). As described above, the 3-bit status signal output from the comparison process on the software (SW) or the comparison circuit on the hardware (HW) includes the voltage values of the LEFT channel, the RIGHT channel, and the MIDDLE channel, and the respective voltage thresholds. The comparison result with (the 1st reference voltage, the 2nd reference voltage, and the 3rd reference voltage) is shown, and according to the combination of the comparison results, the type of the connected audio device is monaural earphone, stereo headphone, earphone It is determined whether the microphone, stereo microphone, headset with two input microphones, or stereo earphone microphone is used.

  If the voltage threshold, that is, the reference voltage in the comparison process on the software (SW) or the comparison circuit on the hardware (HW) is fixed in hardware, the impedance of the input device (microphone) or output device (speaker) Since it is impossible to deal with a case where characteristics are not assumed, a hardware configuration provided with an A / D converter or a D / A converter that can arbitrarily set a voltage threshold, that is, a reference voltage by software (SW) control. .

  When the comparison is performed in the comparison process on the software (SW), the voltage value of the A / D converter 1ch to 3ch (each channel of LEFT, RIGHT, and MIDDLE) inside the portable terminal is set to a voltage threshold set by software control, that is, Compare with reference voltage. An input / output selector circuit for switching input / output of an audio signal is connected to the jack interface for connecting an audio device, and each of the LEFT channel, the RIGHT channel, and the MIDDLE channel is input according to the comparison result with the voltage threshold value. Switch to (microphone) PASS or output (speaker) PASS.

  At this time, the plug recognition signal for recognizing that the audio device is connected to the jack interface is input to the input / output selector circuit, and the connection is made only when it is detected that the audio device is connected. It is possible to start the operation of supplying input / output suitable for the type of audio device to the jack interface.

  Further, the plug recognition signal of the jack interface is input to the audio CODEC, and based on this, the audio CODEC performs an interrupt process for the CPU. Through the interrupt processing to the CPU, the software installed in the portable terminal determines the type of the connected audio device based on the comparison result in the A / D converter, and the input / output value suitable for each audio device ( Set to work with output volume, input gain, etc.

  Alternatively, when the comparison is performed by the comparison circuit on the hardware (HW), a D / A converter and a comparison circuit (comparator) that can arbitrarily set a voltage threshold, that is, a reference voltage by software (SW) control are provided, and The hardware configuration is such that the input / output selector circuit can be directly controlled by the output of the comparison circuit.

  The 3-bit status signal output from the comparison circuit (comparator) is connected to the control unit of the CODEC and the control unit of the input / output selector circuit that switches the input / output of the audio signal. In response, the LEFT channel, RIGHT channel, and MIDDLE channel are switched to input (microphone) PASS or output (speaker) PASS.

  Note that the connection state of the audio device to the jack interface can be recognized as a plug recognition signal from the jack interface by the audio CODEC. Therefore, the audio CODEC performs an interrupt process on the CPU based on the recognition result by the plug recognition signal. By interrupt processing, the software (SW) installed in the mobile terminal recognizes the connection of the audio device to the jack interface, and uses input / output values (output volume, input gain) appropriate for each connected audio device. The operating state of the audio CODEC is set so as to operate.

(Configuration of the first embodiment)
First, as a first embodiment of the portable terminal according to the present invention, a comparison between a converted voltage value of each channel of an audio device connected to a jack interface and a voltage threshold, that is, a reference voltage is set by software (SW). A description will be given of a case where the voltage threshold is used and an A / D converter is used.

  FIG. 1 is a block configuration diagram showing an example of a block configuration in the first embodiment of the portable terminal according to the present invention. Referring to FIG. 1, the portable terminal according to the first embodiment converts the impedance characteristics of the 4-pole jack interface 10 to which the plug of the audio device is connected, the LEFT channel, the RIGHT channel, and the MIDDLE channel into voltage values. An R → V conversion circuit 20; a multi-channel multi-bit A / D converter 30 that outputs a result obtained by comparing the converted voltage value with a voltage threshold, that is, a reference voltage set by software (SW); , A memory 70 and a bus 602 for connecting each circuit. In the A / D converter 30, the voltage value converted by the R → V conversion circuit 20 is converted into a digital signal and output to the CPU 60, and the CPU 60 converts the voltage value from the A / D converter 30. Alternatively, a voltage threshold set in software (SW), that is, a reference voltage may be compared.

  Further, the control unit 41 of the input / output selector circuit that receives the audio CODEC 50, the plug recognition signal 101 of the jack interface 10 and controls the switching of the input / output selector circuit 42, and the input / output signals (LEFT / RIGHT) of the audio CODEC 50 are sent. And an input / output selector circuit 42 connected to the LEFT signal 102, the RIGHT signal 103, and the MIDDLE signal 104 of the jack interface 10. The audio CODEC 50 is configured by being connected to the CPU 60 by a dedicated interface 601.

  In the first embodiment, the audio jack interface 10 corresponds to a four-pole plug, and LEFT channel, RIGHT channel, MIDDLE channel, and GND are wired, and LEFT signal 102, RIGHT signal 102, The MIDDLE signal 104 and GND are connected to support a two-input microphone compatible headset.

  FIG. 2 is an explanatory diagram for explaining a state in which a 4-pole audio device plug is connected to the portable terminal of FIG. That is, as shown in FIG. 2, the LEFT channel impedance R1, RIGHT channel impedance R2, MIDDLE channel impedance R3 and GND of the 4-pole audio device plug 80 are inserted into the respective jacks of the jack interface 10, and The LEFT signal 102, the RIGHT signal 103, the MIDDLE signal 104, and the GND (grounding unit) are connected to the R → V conversion circuit 20 and the input / output selector circuit 42, respectively.

  In addition, as a plug of an audio device, a general three-pole type is also supported. The plug connected to the jack interface 10 is wired with a LEFT channel, a RIGHT channel, and a GND, respectively. Both the LEFT / RIGHT channel is a speaker output, the earphone microphone is a microphone input for the LEFT channel, the RIGHT channel is a speaker output, and the stereo microphone is a microphone input for both the LEFT / RIGHT channel. It also supports a two-pole type monaural earphone. A LEFT channel and a GND are wired to a plug connected to the jack interface 10, and the LEFT channel serves as a speaker output.

  FIG. 3 is an explanatory diagram for explaining a state in which a three-pole audio device plug is connected to the portable terminal of FIG. That is, as shown in FIG. 3, the LEFT channel impedance R1, RIGHT channel impedance R2 and GND of the three-pole audio device plug 90 are inserted into the respective jacks of the jack interface 10, and the LEFT signal 102 and RIGHT signal of the jack interface 10 are inserted. 103 and GND (grounding unit), respectively, and connected to the R → V conversion circuit 20 and the input / output selector circuit 42. The MIDDLE signal 104 of the jack interface 10 is connected to GND (grounding unit).

  In the case of a two-pole type plug such as a monaural earphone, the LEFT channel and GND are wired to the plug connected to the jack interface 10, and the LEFT channel impedances R 1 and GND are connected to the respective jacks of the jack interface 10. Inserted and connected to the LEFT signal 102 and GND (grounding unit) of the jack interface 10, and connected to the R → V conversion circuit 20 and the input / output selector circuit 42. The RIGHT signal 103 and the MIDDLE signal 104 of the jack interface 10 are connected to GND (grounding unit).

(Description of operation of the first embodiment)
Next, an example of the operation of the mobile terminal illustrated in FIG. 1 will be described. As shown in FIG. 2 or FIG. 3, when a 4-pole or 3-pole plug of an audio device is connected to the jack interface 10 of the portable terminal of FIG. 1, the LEFT signal 102, the RIGHT signal 103, and the MIDDLE signal of the jack interface 10 are connected. 104 is input to the R → V conversion circuit 20.

  The R → V conversion circuit 20 converts the LEFT channel impedance R1, the RIGHT channel impedance R2 and the MIDDLE channel impedance R3 of the 4-pole or 3-pole plug of the audio device into a voltage, and the left voltage value V-LEFT201, Output as a right voltage value V-RIGHT 202 and a medium voltage value V-MIDDLE 203.

  That is, as shown in the characteristic table of FIG. 4, the LEFT signal 102, the RIGHT signal 103, and the MIDDLE signal 104 of the jack interface 10 are impedances corresponding to functions (microphone function or speaker function) of each pin of the plug of the audio device. It has characteristics. As described above, the impedance of each signal is converted into a voltage value in the R → V conversion circuit 20, and as shown in FIG. 1, the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202, and the medium voltage value are converted. As V-MIDDLE 203, it is output to 1ch, 2ch and 3ch of the A / D converter 30.

  FIG. 4 is an explanatory diagram showing the magnitude of impedance of each channel of the audio device plug connected to the portable terminal of FIG. 1, and is a headset (headphone, earphone microphone, stereo microphone, 2-input microphone compatible headset). This explains that the impedance of each channel of each audio device plug differs depending on the two-input type earphone microphone).

  For example, in the case of headphones that are three-pole audio equipment plugs, both the LEFT channel and the RIGHT channel have speaker functions, and the LEFT channel impedance R1 and the RIGHT channel impedance R2 are both 300Ω or less, and about 8Ω to about 150Ω. Between. The MIDDLE channel impedance R3 is connected to GND (grounding unit) and is 0Ω.

  In the case of a 2-input microphone-compatible headset that is a 4-pole audio equipment plug, both the LEFT channel and the MIDDLE channel have a microphone function, and both the LEFT channel impedance R1 and the MIDDLE channel impedance R3 are infinitely about 1 KΩ or more. On the other hand, the RIGHT channel is a speaker function, and the RIGHT channel impedance R2 is 300Ω or less, and is between about 8Ω and about 150Ω.

  The left voltage value V-LEFT 201, the right voltage value V-RIGHT 202, and the intermediate voltage value V-MIDDLE 203 are input to the 1ch, 2ch, and 3ch of the multi-channel multi-bit A / D converter 30 as described above. In the A / D converter 30, the voltage values of the input left voltage value V-LEFT 201, right voltage value V-RIGHT 202, and intermediate voltage value V-MIDDLE 203 can be set to arbitrary values in software (SW). A comparison between the possible voltage threshold and the reference voltage Ref is performed. As shown in FIG. 1, the comparison result is stored in the memory 70 via the bus 602, read by the CPU 60, and converted into a control signal for the audio CODEC 50.

  That is, the CPU 60 performs the operation shown in the flowchart of FIG. 5 based on the comparison result of the multi-channel multi-bit A / D converter 30. FIG. 5 is a flowchart showing an example of operations of the A / D converter 30 and the CPU 60 in the mobile terminal of FIG. In FIG. 5, the voltage values of the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202, and the intermediate voltage value V-MIDDLE 203 converted by the R → V conversion circuit 20 are 1ch, 2ch, and 3ch of the A / D converter 30. (Step S1), the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202 and the intermediate voltage value V-MIDDLE 203 that have been input and software (SW) are set to arbitrary values. A comparison is made with the reference voltage Ref that is possible (step S2).

  When the voltage value of the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202, or the intermediate voltage value V-MIDDLE 203 is lower than the reference voltage Ref (the “V-LEFT / V-RIGHT” in step S2), the A / D converter 30 In the case of / V-MIDDLE203 <SW setting reference voltage ”), the output of the ch corresponding to the voltage value lower than the reference voltage Ref among the 1ch, 2ch, and 3ch is set to the“ Low ”level and output to the memory 70 (Step S3). On the other hand, when the voltage value of the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202 or the intermediate voltage value V-MIDDLE 203 is higher than the reference voltage Ref (“V-LEFT / V-RIGHT / V-MIDDLE 203 ≧ In the case of “SW setting reference voltage”, the output of the ch corresponding to the voltage value higher than the reference voltage Ref among the 1ch, 2ch, and 3ch is set to the “High” level and is output to the memory 70 (step S4). .

  Next, the CPU 60 determines combinations of output levels (“Low” level and “High” level) of 1ch, 2ch, and 3ch stored in the memory 70 (step S5). First, as a combination, when the output of 1ch and 3ch is “High” level and the output of 2ch is “Low” level (“1ch = [High], 2ch = [Low], 3ch = [High” in step S5). ]]), As shown in FIG. 4, it is determined that the headset has a four-pole plug and is compatible with a two-input microphone (step S10). In addition, when the output of 3ch is “High” level, and the output level of 1ch and 2ch is other than the above-mentioned combination, the corresponding audio device plug exists as an existing audio device. The discriminating process is aborted as if it is not present.

  In step S5, when the output of 3ch is at the “Low” level (in the case of “3ch = [Low]” in step S5), this is the case where the three-pole audio device plug is connected, and then the 1ch, A combination of output levels of 2ch is determined (step S6). As a combination, when the output of 1ch is “High” level and the output of 2ch is “Low” level (in the case of “1ch = [High], 2ch = [Low]” in step S6), it is shown in FIG. Thus, it is determined as an earphone microphone (step S7). Further, when the outputs of both 1ch and 2ch are at the “Low” level (“1ch = [Low], 2ch = [Low]” in step S6), it is determined as headphones as shown in FIG. 4 ( Step S8). If both the 1ch and 2ch outputs are at “High” level (“1ch = [High], 2ch = [High]” in step S6), it is determined as a stereo microphone as shown in FIG. (Step S9).

  Based on the determined result, the CPU 60 outputs a control signal to the audio CODEC 50 via the dedicated interface 601 in order to switch to connection to a circuit suitable for the connected audio device or to an audio operation. Switch operation. As a result, the output of the output control signals 501, 502, and 503 from the control IO unit of the audio CODEC 50 to the control unit 41 of the input / output selector circuit is output as a different value depending on the determination result of the connected audio device plug. . Therefore, the input / output selector circuit 42 provides the output signal (LEFT / RIGHT) from the audio CODEC 50 as the LEFT signal 102, the RIGHT signal 103, and the MIDDLE signal 104 of the jack interface 10 in a state suitable for the connected audio device. Conversely, the LEFT signal 102, RIGHT signal 103, and MIDDLE signal 104 from the jack interface 10 are supplied as input signals (LEFT / RIGHT) to the audio CODEC 50.

  As described above, when the pin of the connected audio equipment plug has the speaker function, a voltage value lower than the “Low” level, that is, the SW setting reference voltage Ref is recognized. On the other hand, in the case of the microphone function, A voltage value higher than the “High” level, that is, the SW setting reference voltage value Ref is recognized. Therefore, the audio device connected to the jack interface 10 is connected to the headphone, the earphone microphone, the stereo in the control unit 41 of the input / output selector circuit according to the combination of the output control signals 501, 502, and 503 of the control IO unit of the audio CODEC 50. It can be determined whether the headset is a microphone or a two-input microphone-compatible headset. The SW setting reference voltage value Ref is stored in the memory 70 by software control of the CPU 60, and is updated as necessary.

  FIG. 6 is an explanatory diagram for explaining the input / output selector circuit 42 for audio signals and the control unit 41 for controlling the input / output selector circuit 42 in the portable terminal of FIG. In order to prevent circuit malfunction at this time, the plug recognition signal 101 from the jack interface 10 and the output control signals 501, 502, and 503 from the control IO unit of the audio CODEC 50 are input.

  As shown in the flowchart of FIG. 5, the control unit 41 determines the type of the connected audio device plug according to the combination of the output control signals 501, 502, and 503 from the control IO unit of the audio CODEC 50, Based on the determination result, as shown in the explanatory diagram of FIG. 6, the switches SW-A421, SW-B422, SW-C423, SW-D424, SW-E425, and SW-F426 of the input / output selector circuit 42 are turned on / off. Switch states to provide the appropriate PASS for the connected audio device.

  Here, the switch SW-A 421 is a switch for connecting the output signal (LEFT) from the audio CODEC 50 to the LEFT signal 102 of the jack interface, and the SW-B 422 is an input signal to the audio CODEC 50 of the jack interface LEFT signal 102. This is a switch connected to (LEFT). The switch SW-C 423 is a switch for connecting the output signal (RIGHT) from the audio CODEC 50 to the RIGHT signal 103 of the jack interface, and the SW-D 424 is the input signal (input to the audio CODEC 50) of the RIGHT signal 103 of the jack interface. RIGHT). The switch SW-E 425 is a switch for connecting the output signal (MIDDLE) from the audio CODEC 50 to the MIDDLE signal 104 of the jack interface, and the SW-F 426 is an input signal (input to the audio CODEC 50) of the MIDDLE signal 104 of the jack interface. This is a switch connected to MIDDLE).

  When the connected audio device is determined as a headphone, SW-A 421 and SW-C 423 shown in FIG. 6 are used. When the connected audio device is determined as an earphone microphone, the SW shown in FIG. -B422 and SW-C423, and when the connected audio device is determined as a stereo microphone, SW-B422 and SW-D424 shown in FIG. 6 are turned on. If it is determined that the headset is compatible with a two-input microphone that can be used with a four-pole plug, SW-B422, SW-C423, and SW-F426 shown in FIG. 6 are turned on.

  With the above switching operation, the LEFT signal 102, RIGHT signal 103, and MIDDLE signal 104 of the jack interface 10 in FIG. 6 are connected to an appropriate audio signal of the audio CODEC 50 according to the type of the connected audio device.

  Furthermore, as shown in FIG. 7, the plug recognition signal 101 input from the jack interface 10 to the control unit 41 of the input / output selector circuit is also input to the control unit of the audio CODEC 50, and the control unit of the audio CODEC 50 When it is detected by the plug recognition signal 101 that an audio device is connected to the jack interface 10, an interrupt is generated for the CPU 60 via the dedicated interface 601. FIG. 7 is an explanatory diagram illustrating an example of a route for notifying the CPU 60 that an audio device is connected to the jack interface 10 in the mobile terminal of FIG.

  When an interrupt indicating that an audio device is connected via the dedicated interface 601 is generated, the CPU 60 is based on the comparison result between the voltage value detected by the multi-channel multi-bit A / D converter 30 and the SW setting reference voltage Ref. Then, an operation for determining the type of the connected audio device is performed, and a control signal is generated and output to the control IO unit of the audio CODEC 50 based on the determined result. As a result, the control signal from the CPU 60 switches the operation of the audio CODEC 50 to a state suitable for the connected audio device. At the same time, the connection state of the input / output selector circuit 42 is also controlled by the output from the control IO unit of the audio CODEC 50. Based on the signals 501, 502, and 503, a state suitable for the connected audio device is set. Thus, an audio input / output operation can be started by an appropriate software setting value (output volume, input gain, etc.).

(Description of the effect of the first embodiment)
As described above, according to the first embodiment, only one jack interface 10 is used, and the monaural earphone (2-pole jack), stereo headphone (3-pole jack), earphone microphone (3-pole jack), stereo microphone ( It is possible to adapt to multiple types of audio equipment such as a 3-pole jack) and 2-input microphone compatible headset (4-pole jack), a 2-pole plug, a 3-pole plug, and a 4-pole plug. Even if it exists, it becomes possible to provide an audio | voice function fully, without impairing the physical size.

  In addition, since the type determination after connecting the audio device and the setting suitable for each audio device are automatically performed by software control, there is no need for the user to perform the switching operation, and an error in the jack interface to be applied. This also helps prevent insertion and helps reduce the failure rate.

(Configuration example of the second embodiment)
Next, as a second embodiment of the portable terminal according to the present invention, a comparison circuit compares the converted voltage value of each channel of an audio device connected to the jack interface with a voltage threshold, that is, a reference voltage, by hardware (HW ) Will be described. FIG. 8 is a block configuration diagram showing an example of a block configuration in the second embodiment of the portable terminal according to the present invention.

  Referring to FIG. 8, the portable terminal according to the second embodiment has impedance characteristics of a 4-pole jack interface 10 to which a plug of an audio device is connected, a LEFT channel, a RIGHT channel, and a MIDDLE channel. R → V conversion circuit 20 for converting the value V-LEFT 201, the right voltage value V-RIGHT 202, and the intermediate voltage value V-MIDDLE 203, respectively, and the converted voltage values, that is, the left voltage value V-LEFT 201 and the right voltage value V-RIGHT 202, respectively. And the first comparison circuit 31, the second comparison circuit 32, which compare the medium voltage value V-MIDDLE 203 with the voltage threshold, that is, the first reference voltage 851, the second reference voltage 852, and the third reference voltage 853, respectively. The third comparison circuit 33 and the first reference voltage 85 The D / A converter 85 that outputs the second reference voltage 852 and the third reference voltage 853 from the 1ch, 2ch, and 3ch, the right voltage value V-RIGHT 202, and the intermediate voltage value V-MIDDLE 203 are input from the 1ch and 2ch. A multi-channel multi-bit A / D converter 35 that converts the converted voltage values of the RIGHT channel and the MIDDLE channel into digital values, a CPU 60, and a bus 602 that connects each circuit. Yes.

  The D / A converter 85 is connected to the CPU 60 via the bus 602, and the voltage values of the first reference voltage 851, the second reference voltage 852, and the third reference voltage 853 are variably controlled by software (SW) control. Can be set. The voltage values of the RIGHT channel and MIDDLE channel detected by the A / D converter 35 are input to the CPU 60 via the bus 602.

  Further, the control unit 41 of the input / output selector circuit that receives the audio CODEC 50, the plug recognition signal 101 of the jack interface 10 and controls the switching of the input / output selector circuit 42, and the input / output signals (LEFT / RIGHT) of the audio CODEC 50 are sent. And an input / output selector circuit 42 connected to the LEFT signal 102, the RIGHT signal 103, and the MIDDLE signal 104 of the jack interface 10. The audio CODEC 50 is configured by being connected to the CPU 60 by a dedicated interface 601.

  The first comparison result 311, the second comparison result 312 and the third comparison result 313, which are the comparison results of the first comparison circuit 31, the second comparison circuit 32, and the third comparison circuit 33, are input / output. The type of the plug of the audio device that is input to the control unit 41 of the selector circuit 42 and the control IO unit of the audio CODEC 50 and connected to the jack interface 10 is automatically identified, and the connection switching of the input / output selector circuit 42 and the audio are performed. The operation of the CODEC 50 is quickly switched.

  In the second embodiment, the audio jack interface 10 corresponds to a 4-pole plug, a 3-pole plug, and a 2-pole plug. In the case of the 4-pole plug, the LEFT channel, RIGHT channel, MIDDLE channel, and GND are wired, and the LEFT signal 102, RIGHT signal 103, MIDDLE signal 104, and GND are connected, and a headset or stereo that supports two-input microphones. Earphone microphone can also be supported.

  FIG. 9 is an explanatory diagram for explaining a state in which a 4-pole audio device plug is connected to the mobile terminal of FIG. That is, as shown in FIG. 9, the LEFT channel impedance R1, RIGHT channel impedance R2, MIDDLE channel impedance R3 and GND of the 4-pole audio equipment plug 80 are inserted into the respective jacks of the jack interface 10, and the jack interface 10 The LEFT signal 102, the RIGHT signal 103, the MIDDLE signal 104, and the GND (grounding unit) are connected to the R → V conversion circuit 20 and the input / output selector circuit 42, respectively.

  FIG. 10 is an explanatory diagram for explaining a state in which a three-pole audio device plug is connected to the portable terminal of FIG. That is, as shown in FIG. 10, the LEFT channel impedance R1, RIGHT channel impedance R2 and GND of the three-pole audio device plug 90 are inserted into the respective jacks of the jack interface 10, and the LEFT signal 102 and RIGHT signal of the jack interface 10 are inserted. 103 and GND (grounding unit), respectively, and connected to the R → V conversion circuit 20 and the input / output selector circuit 42. The MIDDLE signal 104 of the jack interface 10 is connected to GND (grounding unit).

  Moreover, FIG. 11 is explanatory drawing explaining the state which connected the 2 pole audio equipment plug to the portable terminal of FIG. That is, as shown in FIG. 11, the LEFT channel impedances R1 and GND of the two-pole audio device plug 95 are inserted into the respective jacks of the jack interface 10, and the LEFT signal 102 and the GND (grounding unit) of the jack interface 10 are respectively To the R → V conversion circuit 20 and the input / output selector circuit 42. The RIGHT signal 103 and the MIDDLE signal 104 of the jack interface 10 are connected to GND (grounding unit).

  FIG. 12 is a block diagram showing an example of the configuration of a comparison circuit that compares the voltage values of the LEFT signal 102, the RIGHT signal 103, and the MIDDLE signal 104 with respective voltage thresholds in the mobile terminal of FIG. As shown in FIG. 12, the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202, and the intermediate voltage value V-MIDDLE 203 obtained by converting the impedance characteristics of the LEFT signal 102, the RIGHT signal 103, and the MIDDLE signal 104, respectively, and the respective voltages are shown. The first comparison circuit 31, the second comparison circuit 32, and the third comparison circuit 33 are used as comparison circuits that compare the threshold, that is, the first reference voltage 851, the second reference voltage 852, and the third reference voltage 853. The comparison results in the respective comparison circuits are output as the first comparison result 311, the second comparison result 312, and the third comparison result 313, as shown in FIG. The control unit 41 and the control IO unit of the audio CODEC 50 are supplied.

  FIG. 13 is an explanatory diagram for explaining the audio signal input / output selector circuit 42 and the control unit 41 for controlling the input / output selector circuit 42 in the portable terminal of FIG. As shown in FIG. 13, the control unit 41 includes a first comparison result 311 and a second comparison result output from the first comparison circuit 31, the second comparison circuit 32, and the third comparison circuit 33, respectively. 312 and the third comparison result 313 indicate that the plug recognition signal 101 and the audio CODEC 50 output from the jack interface 10 are used to prevent circuit malfunction when the audio device is not connected and output from the audio CODEC 50 in the unset state. It is input together with the output control signal 501 output from the control IO unit.

  The control unit 41 determines the type of the audio device plug connected to the jack interface 10 according to the combination of the first comparison result 311, the second comparison result 312, and the third comparison result 313, and the determination result The switch SW-A421, SW-B422, SW-C423, SW-D424, SW-E425, and SW-F426 of the input / output selector circuit 42 are switched on / off based on the PASS.

  Here, the switch SW-A 421 is a switch for connecting the output signal (LEFT) from the audio CODEC 50 to the LEFT signal 102 of the jack interface, and the SW-B 422 is an input signal to the audio CODEC 50 of the jack interface LEFT signal 102. This is a switch connected to (LEFT). The switch SW-C 423 is a switch for connecting the output signal (RIGHT) from the audio CODEC 50 to the RIGHT signal 103 of the jack interface, and the SW-D 424 is the input signal (input to the audio CODEC 50) of the RIGHT signal 103 of the jack interface. RIGHT). The switch SW-E425 is a switch for connecting the output signal (MIDDLE) from the audio CODEC 50 to the MIDDLE signal 104 of the jack interface, and the SW-F426 is an input signal (input to the audio CODEC 50) of the MIDDLE signal 104 of the jack interface. This is a switch connected to MIDDLE).

  FIG. 14 is an explanatory diagram illustrating an example of a path for notifying the CPU 60 that an audio device is connected to the jack interface 10 in the mobile terminal of FIG. As shown in FIG. 14, the plug recognition signal 101 input from the jack interface 10 to the control unit 41 of the input / output selector circuit 42 is also input to the control unit of the audio CODEC 50, and the control unit of the audio CODEC 50 When it is detected by the recognition signal 101 that an audio device is connected to the jack interface 10, the CPU 60 is notified via the dedicated interface 601.

  As shown in FIG. 14, the control unit of the audio CODEC 50 includes a first comparison result 311 output from the first comparison circuit 31, a second comparison circuit 32, and a third comparison circuit 33. 2 comparison result 312 and third comparison result 313 are input, and the control unit of the audio CODEC 50 transmits the first comparison result 311, the second comparison result 312, and the second comparison result to the CPU 60 via the dedicated interface 601. 3 comparison result 313 and the type of the audio device plug connected to the jack interface 10 is determined according to the combination of the first comparison result 311, the second comparison result 312, and the third comparison result 313. Then, based on the determination result, the operation of the audio CODEC 50 is performed in a state suitable for the connected audio device. Replace Ri.

  As shown in FIG. 14, the first reference voltage 851, the second reference voltage 852 and the third reference voltage 851, which are input to the first comparison circuit 31, the second comparison circuit 32, and the third comparison circuit 33, respectively. The reference voltage 853 is generated by the D / A converter 85 based on a control signal designated by the software (SW) control from the CPU 60 via the bus 602.

  FIG. 15 is an explanatory diagram showing the magnitude of impedance of each channel of the audio equipment plug connected to the portable terminal of FIG. 8, and the correspondence between the LEFT signal 102, the RIGHT signal 103 and the MIDDLE signal 104 and each audio equipment plug. It is an impedance characteristic table | surface which shows a relationship. As shown in FIG. 15, the headphone, earphone microphone, stereo microphone, 2-input microphone-compatible headset (2-input earphone microphone), stereo earphone microphone, monaural speaker / earphone, impedance of each channel of each audio device plug Is different.

  For example, in the case of headphones that are three-pole audio equipment plugs, both the LEFT channel and the RIGHT channel have speaker functions, and the LEFT channel impedance R1 and the RIGHT channel impedance R2 are both 300Ω or less, and about 8Ω to about 150Ω. Between. The MIDDLE channel impedance R3 is connected to GND (grounding unit) and is 0Ω.

  In the case of a 2-input microphone compatible headset (2-input earphone microphone) that is a 4-pole audio equipment plug, both the LEFT channel and the MIDDLE channel have a microphone function, and the LEFT channel impedance R1 and the MIDDLE channel impedance R3 are both The RIGHT channel is a speaker function, and the RIGHT channel impedance R2 is 300Ω or less, and is between about 8Ω and about 150Ω.

  In the case of a monaural speaker / earphone that is a two-pole audio device plug, the LEFT channel is a speaker function, and the LEFT channel impedance R1 is 300Ω or less, and is between about 8Ω and about 150Ω. The RIGHT channel impedance R2 and the MIDDLE channel impedance R3 are connected to GND (ground portion) and are 0Ω.

(Description of the operation of the second embodiment)
Next, an example of the operation of the mobile terminal illustrated in FIG. 8 will be described. As shown in any of FIGS. 9 to 11, when a 4-pole, 3-pole, or 2-pole plug of an audio device is connected to the jack interface 10 of the portable terminal of FIG. 8, the LEFT signal 102 of the jack interface 10; RIGHT signal 103 and MIDDLE signal 104 are input to R → V conversion circuit 20.

  The R → V conversion circuit 20 converts the LEFT channel impedance R1, the RIGHT channel impedance R2, and the MIDDLE channel impedance R3 of the 4-pole, 3-pole, or 2-pole plug of the audio device into voltages, and the left voltage value V -LEFT 201, right voltage value V-RIGHT 202 and medium voltage value V-MIDDLE 203 are output. Here, as described in FIG. 15, the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202, and the medium voltage value V-MIDDLE 203 depend on the type of audio device, that is, each pin of the audio device plug is Depending on the impedance characteristic of the function (microphone or speaker) it has, it is converted to a different voltage value.

  As shown in FIG. 8, the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202, and the intermediate voltage value V-MIDDLE 203 output from the R → V conversion circuit 20 are the first comparison circuit 31 and the second comparison circuit. The right voltage value V-RIGHT 202 and the intermediate voltage value V-MIDDLE 203 are input to the ch 1 and ch 2 of the A / D converter 35, respectively, input to the circuit 32 and the third comparison circuit 33.

  In the first comparison circuit 31, the second comparison circuit 32, and the third comparison circuit 33, the left voltage value V-LEFT 201, the right voltage value V-RIGHT 202, and the intermediate voltage value V− from the R → V conversion circuit 20. Compare the MIDDLE 203 with the first reference voltage 851, the second reference voltage 852, and the third reference voltage 853 from the D / A converter 85 set by software (SW) control. Are output as the first comparison result 311, the second comparison result 312, and the third comparison result 313.

  The first comparison result 311, the second comparison result 312 and the third comparison result 313 output from the first comparison circuit 31, the second comparison circuit 32, and the third comparison circuit 33, respectively, are shown in FIG. As shown in the figure, the control unit 41 of the input / output selector circuit 42 and the control IO unit of the audio CODEC 50 are input to enable the connection state suitable for the connected audio device and the CODEC operation of the audio signal, and the first comparison The result 311, the second comparison result 312, and the third comparison result 313, that is, the connection state of the input / output selector circuit 42 and the operation state of the audio CODEC 50 are sent to the CPU 60 (that is, software (SW)) via the dedicated interface 601. Can be notified.

  Further, the A / D converter to which the right voltage value V-RIGHT 202 and the intermediate voltage value V-MIDDLE 203 are input converts the right voltage value V-RIGHT 202 and the intermediate voltage value V-MIDDLE 203 into a digital signal, and uses the bus 602. To the CPU 60. The CPU 60 determines whether the audio device plug connected to the jack interface 10 is a 2-pole plug, a 3-pole plug, or a 4-pole plug based on the digitally converted right voltage value V-RIGHT 202 and medium voltage value V-MIDDLE 203. It is possible to determine.

  That is, as shown in the characteristic table of FIG. 15, when the impedance of the MIDDLE signal 104 is 0Ω (GND) (that is, the medium voltage value V-MIDDLE 203 is 0 V), it indicates that the plug is not a four-pole plug. In this case, when the impedance of the RIGHT signal 103 is 0Ω (GND) (that is, the right voltage value V-RIGHT 202 is 0 V), it indicates a two-pole plug, while the impedance of the RIGHT signal 103 is 0Ω (GND) ( That is, when the right voltage value V-RIGHT 202 is not 0 V), it indicates a three-pole plug. Further, when the impedance of the MIDDLE signal 104 is not 0Ω (GND) (that is, the medium voltage value V-MIDDLE 203 is 0 V), it indicates that the plug is a four-pole plug.

  The jack interface 10 also generates a plug recognition signal 101 indicating that an audio device plug has been connected, and outputs the plug recognition signal 101 to the control unit 41 of the input / output selector circuit 42 and the control IO unit of the audio CODEC 50. The operation timing of the control unit 41 of the output selector circuit 42 and the control IO unit of the audio CODEC 50 is controlled. Further, the control IO unit of the audio CODEC 50 that has received the plug recognition signal 101 from the jack interface 10 can notify the CPU 60 (that is, software (SW)) via the dedicated interface 601.

  When receiving the plug recognition signal 101 from the control IO unit of the audio CODEC 50, the CPU 60 performs an operation as shown in the flowchart of FIG. FIG. 16 is a flowchart showing an example of the operation of the CPU 60 in the mobile terminal of FIG. In FIG. 16, when the plug recognition signal 101 is received from the control IO unit of the audio CODEC 50 (Yes in step S21), the voltage detection results of ch1 and ch2 of the A / D converter 35, that is, the right voltage value V-RIGHT 202, the medium voltage value. The digital value of V-MIDDLE 203 is read from the A / D converter 35 via the bus 602 (step S22).

  Of the voltage detection results of ch1 and ch2 read by the A / D converter 35, it is first determined whether or not the voltage detection result of ch2 is 0V (step S23). When the voltage detection result of ch2 is not 0V (No in step S23), the medium voltage value V-MIDDLE 203 is other than 0V, that is, the impedance of the MIDDLE signal 104 is other than 0Ω (GND). As explained, it turns out that the audio equipment plug connected to the jack interface 10 is a four-pole plug.

  Therefore, next, in order to determine which of the four-pole plugs the two-input type earphone microphone or the stereo earphone microphone is connected, the ch3 reference voltage of the D / A converter 85 is set, and the third The reference voltage 853 is output (step S24), and the third comparison circuit 33 compares the third reference voltage 853 of the D / A converter 85 with the intermediate voltage value V-MIDDLE 203 to obtain the third comparison. The third comparison result 313 output from the circuit 33 is read via the dedicated interface 601 (step S25).

  As the read third comparison result 313, when the medium voltage value V-MIDDLE 203 is equal to or higher than the third reference voltage 853 (in the case of “(V-MIDDLE) ≧ (reference voltage)” in step S25), FIG. As shown in FIG. 15, it is determined that it is a two-input earphone microphone (a headset corresponding to a two-input microphone) (step S26). In such a case, the control unit 41 of the input / output selector circuit 42 to which the first comparison result 311, the second comparison result 312, and the third comparison result 313 are input also automatically has two inputs of a four-pole plug. The switch SW-B 422, the switch SW-C 423, and the switch SW-F 426 of the input / output selector circuit 42 shown in FIG.

  On the other hand, as the read third comparison result 313, when the intermediate voltage value V-MIDDLE 203 is lower than the third reference voltage 853 (in the case of “(V-MIDDLE) <(reference voltage)” in step S25). As shown in FIG. 15, it is determined that it is a stereo earphone microphone (step S27). In such a case, the control unit 41 of the input / output selector circuit 42 to which the first comparison result 311, the second comparison result 312, and the third comparison result 313 are input is also automatically a four-pole plug stereo earphone. It is determined that it is a microphone, and the switch SW-B422, switch SW-C423, and switch SW-E425 of the input / output selector circuit 42 shown in FIG. 13 are set to ON.

  Further, when the voltage detection result of ch2 is 0V (Yes in step S23), the intermediate voltage value V-MIDDLE 203 is 0V, that is, the impedance of the MIDDLE signal 104 is 0Ω (GND), and in FIG. As explained, it turns out that the audio equipment plug connected to the jack interface 10 is a three-pole plug or a two-pole plug.

  Therefore, next, in order to determine whether the plug is a three-pole plug or a two-pole plug, it is determined whether or not the voltage detection result of ch1 is 0V (step S28). When the voltage detection result of ch1 is 0V (Yes in step S28), the right voltage value V-RIGHT 202 is 0V, that is, the impedance of the RIGHT signal 103 is 0Ω (GND), which has been described with reference to FIG. As described above, the audio device plug connected to the jack interface 10 is a two-pole plug, and is determined to be a monaural speaker / earphone (step S29). In such a case, the control unit 41 of the input / output selector circuit 42 to which the first comparison result 311, the second comparison result 312, and the third comparison result 313 are input is also automatically a monaural speaker with a two-pole plug. / Earphone is discriminated and only the switch SW-A 421 of the input / output selector circuit 42 shown in FIG. 13 is set to ON.

  On the other hand, if the voltage detection result of ch1 is not 0V (No in step S28), the medium voltage value V-MIDDLE 203 is 0V, that is, the impedance of the MIDDLE signal 104 is 0Ω (GND), and the right When the voltage value V-RIGHT 202 is other than 0V, that is, when the impedance of the RIGHT signal 103 is other than 0Ω (GND), the audio device plug connected to the jack interface 10 is a three-pole plug as described with reference to FIG. It turns out that this is the case.

  Therefore, next, in order to determine which of the three-pole plug is connected to the headphone, the earphone microphone, or the stereo microphone, the ch1 and ch2 reference voltages of the D / A converter 85 are set, and the first The reference voltage 851 and the second reference voltage 852 are output (step S30), the first reference voltage 851 of the D / A converter 85 is compared with the left voltage value V-LEFT 201, and the second of the D / A converter 85 is output. The comparison between the reference voltage 852 and the right voltage value V-RIGHT 202 is performed by the first comparison circuit 31 and the second comparison circuit 32, respectively, and from the first comparison circuit 31 and the second comparison circuit 32, respectively. The output first comparison result 311 and second comparison result 312 are read via the dedicated interface 601 (step S31).

  Next, as the read first comparison result 311, when the left voltage value V-LEFT 201 is equal to or higher than the first reference voltage 851 (in the case of “(V-LEFT) ≧ (reference voltage)” in step S <b> 31). When the read first comparison result 311 is set to “High” (step S32), the left voltage value V-LEFT 201 is lower than the first reference voltage 851 as the read first comparison result 311. (When “(V-LEFT) <(reference voltage)” in step S31), the read first comparison result 311 is set to “Low” (step S33).

  Similarly, when the right voltage value V-RIGHT 202 is equal to or higher than the second reference voltage 852 as the read second comparison result 312 (in the case of “(V-RIGHT) ≧ (reference voltage)” in step S31). Sets the read second comparison result 312 to “High” (step S 32), and on the other hand, as the read second comparison result 312, the right voltage value V-RIGHT 202 is lower than the second reference voltage 852. In the case (“(V-RIGHT) <(reference voltage)” in step S31), the read second comparison result 312 is set to “Low” (step S33).

  Thereafter, by combining the setting results of “Low” and “High” of the first comparison result 311 and the second comparison result 312, it is determined which of the headphones, the earphone microphone, and the stereo microphone is connected ( Step S34). When both the first comparison result 311 and the second comparison result 312 are “Low” (in the case of “first = [Low], second = [Low]” in step S34), FIG. As shown in FIG. 5, it is determined that the headphone is a stereo headphone (step S35). In such a case, the control unit 41 of the input / output selector circuit 42 to which the first comparison result 311, the second comparison result 312 and the third comparison result 313 are input is also automatically a three-pole plug headphone. It is discriminated that the switch SW-A 421 and the switch SW-C 423 of the input / output selector circuit 42 shown in FIG.

  Further, when the first comparison result 311 is “High” and the second comparison result 312 is “Low” (in the case of “first = [High], second = [Low]” in step S34). ) Is determined to be an earphone microphone as shown in FIG. 15 (step S36). In such a case, the control unit 41 of the input / output selector circuit 42 to which the first comparison result 311, the second comparison result 312, and the third comparison result 313 are input is also automatically a three-pole plug earphone microphone. And the switches SW-B422 and SW-C423 of the input / output selector circuit 42 shown in FIG. 13 are set to ON.

  In addition, when both the first comparison result 311 and the second comparison result 312 are “High” (in the case of “first = [High], second = [High]” in step S34), As shown in FIG. 15, it is determined that it is a stereo microphone (step S37). In such a case, the control unit 41 of the input / output selector circuit 42 to which the first comparison result 311, the second comparison result 312, and the third comparison result 313 are input is also automatically a three-pole plug earphone microphone. And the switches SW-B422 and SW-D424 of the input / output selector circuit 42 shown in FIG. 13 are set to ON.

  By automatically detecting the state of the audio jack, that is, the type of the audio equipment plug connected to the jack interface 10 by the automatic recognition function of the audio jack like this, the connected audio equipment is discriminated and the input is turned on. After the output selector circuit 42 is switched to an appropriate connection state, the operation state of the audio CODEC 50 is set to an appropriate value as a setting value (output volume, input gain) that can be variably controlled by software (SW). The operation can be started.

(Description of the effect of the second embodiment)
As described above, according to the second embodiment, even when hardware (HW) comparison means is used, as in the first embodiment, only one jack interface 10 is used. Monaural speaker / earphone (2-pole jack), stereo headphone (3-pole jack), earphone microphone (3-pole jack), stereo microphone (3-pole jack), 2-input microphone compatible headset (4-pole jack), stereo earphone microphone It is possible to adapt to multiple types of audio equipment such as (4-pole jack), 2-pole plug, 3-pole plug and 4-pole plug, and even the miniaturized portable terminal loses its physical size. Therefore, the audio function can be sufficiently provided.

  In addition, since the type determination after connecting the audio device and the setting suitable for each audio device are automatically performed by software control, there is no need for the user to perform the switching operation, and an error in the jack interface to be applied. This also helps prevent insertion and helps reduce the failure rate.

The configuration of the preferred embodiment of the present invention has been described above. However, it should be noted that such examples are merely illustrative of the invention and do not limit the invention in any way. Those skilled in the art will readily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention. For example, in the above-described embodiment, the types of audio devices that are automatically determined by being connected to the jack interface 10 are monaural speakers / earphones (2-pole jack), stereo headphones (3-pole jack), earphone microphones (3-pole jack). ), Stereo microphone (3-pole jack), 2-input microphone compatible headset (4-pole jack), or stereo earphone microphone (4-pole jack), these audio devices are typical audio devices. The present invention is not limited to such a case, and can be applied to any audio device as long as the audio device has a microphone function and / or a speaker function. Not only for future devices but also for future devices. It is possible to adapt only wear specific change processing or minor modifications.
Moreover, the embodiment of the present invention can be expressed as the following configuration in addition to the configuration (1) in the means for solving the problems.
(2) The portable terminal according to (1), wherein an operation for switching a connection state between the audio CODEC and the jack interface and an input / output level of an audio signal is performed by software control.
(3) The audio device determination means includes conversion means for converting impedances of LEFT channels, RIGHT channels, and MIDDLE channels of the audio equipment connected to the jack interface into voltage values, and LEFT converted by the conversion means. An A / D converter that outputs a result of comparing the voltage value of each of the channel, the RIGHT channel, and the MIDDLE channel with a preset voltage threshold, and includes a LEFT channel, a RIGHT channel output from the A / D converter, The portable terminal according to (1) or (2), wherein the type of the connected audio device is determined based on a combination result of comparison with the voltage threshold value of each MIDDLE channel.
(4) The audio device discriminating means includes: a conversion means for converting impedances of LEFT channel, RIGHT channel, and MIDDLE channel of the audio equipment connected to the jack interface into voltage values; and LEFT converted by the conversion means. A / D converter that converts each voltage value of the channel, RIGHT channel, and MIDDLE channel into a digital value, and a voltage value of each of the LEFT channel, RIGHT channel, and MIDDLE channel that is converted into a digital value by the A / D converter, Comparison means for comparing with a preset voltage threshold, and the voltage threshold for each of the LEFT channel, RIGHT channel, and MIDDLE channel output from the comparison means Based on a combination of the result of comparison between the portable terminal of the determines the type of the connected the audio device (1) or (2).
(5) The audio device determination means generates conversion voltage means for converting impedances of LEFT channel, RIGHT channel, and MIDDLE channel of the audio device connected to the jack interface into voltage values, and generates a preset voltage threshold value. A D / A converter, and at least a comparison circuit that compares the voltage values of the LEFT channel, RIGHT channel, and MIDDLE channel converted by the conversion means with a voltage threshold generated in advance by the D / A converter, The type of the connected audio device is determined based on a combination of comparison results with the voltage threshold values of the LEFT channel, the RIGHT channel, and the MIDDLE channel output from the comparison circuit. Portable terminal 1) or (2).
(6) The operation state of the audio CODEC and the connection state between the audio CODEC and the jack interface are switched according to the comparison result with the voltage threshold value of each of the LEFT channel, the RIGHT channel, and the MIDDLE channel output from the comparison circuit. (5) Mobile terminal.
(7) Based on the comparison result of both the voltage values of the RIGHT channel and the MIDDLE channel and 0 V, the audio device plug connected to the jack interface is at least a 2-pole plug, a 3-pole plug, or a 4-pole plug. The mobile terminal according to any one of the above (3) to (6), which determines whether there is any.
(8) The voltage threshold value to be compared with the voltage value of each of the LEFT channel, RIGHT channel, and MIDDLE channel can be changed to any value by software control. Mobile device.
(9) The audio device discriminating means connects the audio device when the voltage values of both the LEFT channel and the MIDDLE channel are higher than the voltage threshold and the voltage value of the RIGHT channel is lower than the voltage threshold. The mobile terminal according to any one of (3) to (8), wherein the mobile terminal is determined to be a four-pole plug type two-input microphone-compatible headset.
(10) The audio device discriminating means is such that the voltage value of the MIDDLE channel is not 0V, the voltage values of both the MIDDLE channel and the RIGHT channel are lower than the voltage threshold value, and the voltage value of the LEFT channel is the voltage. The portable terminal according to any one of (3) to (9), wherein when the audio device is higher than a threshold, the connected audio device is determined to be a four-pole plug type stereo earphone microphone.
(11) When the voltage value of the MIDDLE channel is 0 V, the voltage value of the RIGHT channel is lower than the voltage threshold value, and the voltage value of the LEFT channel is higher than the voltage threshold value The portable terminal according to any one of (3) to (10), wherein the connected audio device is determined to be a three-pole plug type earphone microphone.
(12) When the voltage value of the MIDDLE channel is 0V and the voltage value of both the LEFT channel and the RIGHT channel is lower than the voltage threshold, the audio device determination unit determines that the connected audio device is 3 The mobile terminal according to any one of (3) to (11), wherein the mobile terminal is determined to be a polar plug type headphone.
(13) When the voltage value of the MIDDLE channel is 0 V and the voltage values of both the LEFT channel and the RIGHT channel are higher than the voltage threshold value, the audio device determination unit determines that the connected audio device is 3 The portable terminal according to any one of (3) to (12), wherein the portable terminal is determined to be a polar plug type stereo microphone.
(14) The audio device determining means determines that the connected audio device is a two-pole plug type monaural earphone when the voltage values of both the MIDDLE channel and the RIGHT channel are 0V. Or any one of (13).
(15) A case where plug recognition means for recognizing that the plug of the audio device is connected to the jack interface is recognized, and the plug recognition means recognizes that the plug of the audio device is connected to the jack interface The portable terminal according to any one of (1) to (14), wherein the operation of the audio device determination means for determining the type of the connected audio device is started.
(16) A single 4-pole jack interface capable of connecting a plurality of types of audio equipment is provided, and the impedance magnitude of each of the LEFT channel, RIGHT channel, and MIDDLE channel of the audio equipment connected to the jack interface An audio device identification method in a portable terminal that identifies the type of the connected audio device by identifying the audio device, and the audio CODEC and the jack for converting an audio signal based on the identified type of the audio device An audio device determination method for switching at least an input / output level of an audio signal and a connection state with an interface.
(17) The audio device determination method according to (16), wherein an operation of switching a connection state between the audio CODEC and the jack interface and an input / output level of an audio signal is performed by software control.
(18) A conversion step for converting the impedances of the LEFT channel, RIGHT channel, and MIDDLE channel of the audio device connected to the jack interface into voltage values, and the LEFT channel, RIGHT channel, and MIDDLE channel converted by the conversion step. A comparison step for outputting a result of comparing each voltage value with a preset voltage threshold, and a comparison result with the voltage threshold for each of the LEFT channel, RIGHT channel, and MIDDLE channel obtained by the comparison step. The audio device identification method according to (16) or (17), wherein the type of the connected audio device is determined based on the combination of the above.
(19) The audio device determination method according to (18), wherein the voltage threshold value to be compared with the voltage value of each of the LEFT channel, the RIGHT channel, and the MIDDLE channel can be changed to an arbitrary value by software control.
(20) Based on the comparison result between the voltage values of the RIGHT channel and the MIDDLE channel and 0 V, the audio device plug connected to the jack interface is at least a 2-pole plug, a 3-pole plug, or a 4-pole plug. (18) or (19) the audio device discriminating method of discriminating whether or not there is.
(21) Any one of the above (18) to (20), wherein the voltage threshold value to be compared with the voltage value of each of the LEFT channel, RIGHT channel, and MIDDLE channel can be changed to an arbitrary value by software control. Audio device identification method.
(22) An audio device determination program that implements at least a part of the audio device determination method of any one of (16) to (21) as a program executable by a computer.
(23) A program recording medium in which the audio device determination program of (22) is recorded on a computer-readable recording medium.

It is a block block diagram which shows an example of the block configuration in 1st Embodiment of the portable terminal by this invention. It is explanatory drawing explaining the state which connected the 4 pole audio equipment plug to the portable terminal of FIG. It is explanatory drawing explaining the state which connected the 3 pole audio equipment plug to the portable terminal of FIG. It is explanatory drawing which shows the magnitude | size of the impedance of each channel of the audio equipment plug connected to the portable terminal of FIG. 3 is a flowchart illustrating an example of operations of an A / D converter and a CPU in the mobile terminal of FIG. FIG. 2 is an explanatory diagram illustrating an audio signal input / output selector circuit and a control unit that controls the input / output selector circuit in the portable terminal of FIG. 1. FIG. 2 is an explanatory diagram illustrating an example of a path for notifying a CPU that an audio device is connected to a jack interface in the portable terminal of FIG. 1. It is a block block diagram which shows an example of the block configuration in 2nd Embodiment of the portable terminal by this invention. It is explanatory drawing explaining the state which connected the 4 pole audio equipment plug to the portable terminal of FIG. It is explanatory drawing explaining the state which connected the 3 pole audio equipment plug to the portable terminal of FIG. It is explanatory drawing explaining the state which connected the 2 pole audio equipment plug to the portable terminal of FIG. FIG. 9 is a configuration diagram illustrating an example of a configuration of a comparison circuit that compares voltage values of LEFT signals, RIGHT signals, and MIDDLE signals with respective voltage thresholds in the mobile terminal of FIG. 8. FIG. 9 is an explanatory diagram illustrating an audio signal input / output selector circuit and a control unit that controls the input / output selector circuit in the portable terminal of FIG. 8. FIG. 9 is an explanatory diagram illustrating an example of a path for notifying a CPU that an audio device is connected to a jack interface in the mobile terminal of FIG. 8. It is explanatory drawing which shows the magnitude | size of the impedance of each channel of the audio equipment plug connected to the portable terminal of FIG. It is a flowchart which shows an example of operation | movement of CPU in the portable terminal of FIG.

Explanation of symbols

10 Jack Interface 20 R → V Conversion Circuit 30 A / D Converter 31 First Comparison Circuit 32 Second Comparison Circuit 33 Third Comparison Circuit 35 A / D Converter 41 Control Unit 42 of Input / Output Select Circuit Input / Output Selector Circuit 50 Audio CODEC
60 CPU
70 Memory 80 4-pole audio equipment plug 85 D / A converter 90 3-pole audio equipment plug 95 2-pole audio equipment plug 101 Plug recognition signal 102 LEFT signal 103 RIGHT signal 104 MIDDLE signal 201 Left voltage value V-LEFT
202 Right voltage value V-RIGHT
203 Medium voltage value V-MIDDLE
311 First comparison result 312 Second comparison result 313 Third comparison result 421 Switch SW-A
422 Switch SW-B
423 Switch SW-C
424 Switch SW-D
425 Switch SW-E
426 Switch SW-F
501, 502, 503 Output control signal 601 Dedicated interface 602 Bus 851 First reference voltage 852 Second reference voltage 853 Third reference voltage

Claims (23)

  In a portable terminal having one 4-pole jack interface capable of connecting a plurality of types of audio devices, the impedance of each of the LEFT channel, RIGHT channel, and MIDDLE channel of the audio device connected to the jack interface is large. An audio CODEC that converts the audio signal based on the type of the audio device determined by the audio device determination unit. A portable terminal characterized by switching at least a connection state between the terminal and the jack interface and an input / output level of an audio signal.   2. The portable terminal according to claim 1, wherein an operation of switching a connection state between the audio CODEC and the jack interface and an input / output level of an audio signal is performed by software control.   The audio device discriminating means includes: a conversion means for converting impedances of LEFT channel, RIGHT channel, and MIDDLE channel of the audio equipment connected to the jack interface into voltage values; a LEFT channel, RIGHT converted by the conversion means; An A / D converter that outputs a result of comparing the voltage value of each of the channel and the MIDDLE channel with a preset voltage threshold, and each of the LEFT channel, the RIGHT channel, and the MIDDLE channel output from the A / D converter The mobile terminal according to claim 1, wherein the type of the connected audio device is determined based on a combination of a comparison result with the voltage threshold.   The audio device discriminating means includes: a conversion means for converting impedances of LEFT channel, RIGHT channel, and MIDDLE channel of the audio equipment connected to the jack interface into voltage values; a LEFT channel, RIGHT converted by the conversion means; A / D converter that converts the voltage value of each channel and MIDDLE channel into a digital value, and the voltage value of each of the LEFT channel, RIGHT channel, and MIDDLE channel converted into a digital value by the A / D converter is set in advance. Comparison means for comparing with a voltage threshold value, and each of the voltage threshold values of the LEFT channel, RIGHT channel, and MIDDLE channel output from the comparison means. Based on a combination of the compare result, the portable terminal according to claim 1 or 2, characterized in that determines the type of the connected the audio equipment.   The audio device discriminating unit includes a conversion unit that converts impedances of LEFT channel, RIGHT channel, and MIDDLE channel of the audio device connected to the jack interface into voltage values, and a D / A that generates a preset voltage threshold value. A comparator and a comparison circuit that compares the voltage values of the LEFT channel, the RIGHT channel, and the MIDDLE channel converted by the conversion means with a voltage threshold value generated in advance by the D / A converter, and includes at least the comparison circuit. The type of the connected audio device is determined based on a combination of comparison results with the voltage threshold values of the LEFT channel, RIGHT channel, and MIDDLE channel output from The mobile terminal according to claim 1 or 2.   The operation state of the audio CODEC and the connection state between the audio CODEC and the jack interface are switched according to the comparison result with the voltage threshold value of each of the LEFT channel, RIGHT channel, and MIDDLE channel output from the comparison circuit. The mobile terminal according to claim 5.   Based on the comparison result of both the voltage values of the RIGHT channel and the MIDDLE channel and 0 V, whether the audio device plug connected to the jack interface is at least a 2-pole plug, a 3-pole plug, or a 4-pole plug The mobile terminal according to claim 3, wherein the mobile terminal is discriminated.   The voltage threshold value to be compared with the voltage value of each of the LEFT channel, RIGHT channel, and MIDDLE channel can be changed to an arbitrary value by software control. Mobile device.   When the voltage value of both the LEFT channel and the MIDDLE channel is higher than the voltage threshold value and the voltage value of the RIGHT channel is lower than the voltage threshold value, the audio device determination unit determines that the connected audio device is 4 9. The portable terminal according to claim 3, wherein the portable terminal is determined to be a pole plug type two-input microphone compatible headset.   The audio device discriminating unit is configured such that the voltage value of the MIDDLE channel is not 0 V, the voltage values of both the MIDDLE channel and the RIGHT channel are lower than the voltage threshold value, and the voltage value of the LEFT channel is equal to or higher than the voltage threshold value. The portable terminal according to claim 3, wherein when it is high, the connected audio device is determined to be a four-pole plug type stereo earphone microphone.   The audio device discriminating means is connected when the voltage value of the MIDDLE channel is 0V, the voltage value of the RIGHT channel is lower than the voltage threshold value, and the voltage value of the LEFT channel is higher than the voltage threshold value. 11. The portable terminal according to claim 3, wherein the audio device is determined to be a three-pole plug type earphone microphone.   When the voltage value of the MIDDLE channel is 0V and the voltage values of the LEFT channel and the RIGHT channel are both lower than the voltage threshold, the connected audio device is a three-pole plug type. The mobile terminal according to claim 3, wherein the mobile terminal is determined to be a headphone.   When the voltage value of the MIDDLE channel is 0V and the voltage values of both the LEFT channel and the RIGHT channel are higher than the voltage threshold, the connected audio device is a three-pole plug type. The mobile terminal according to claim 3, wherein the mobile terminal is identified as a stereo microphone.   The audio device determining means determines that the connected audio device is a two-pole plug type monaural earphone when the voltage values of both the MIDDLE channel and the RIGHT channel are 0V. The mobile terminal according to any one of 3 to 13.   Plug recognition means for recognizing that the plug of the audio device is connected to the jack interface, and when the plug recognition means recognizes that the plug of the audio device is connected to the jack interface 15. The portable terminal according to claim 1, wherein an operation of the audio device determination unit that determines the type of the audio device that has been performed is activated.   A single 4-pole jack interface capable of connecting a plurality of types of audio equipment is provided, and the magnitude of impedance of each of the LEFT channel, RIGHT channel, and MIDDLE channel of the audio equipment connected to the jack interface is identified. An audio device determination method in a mobile terminal for determining the type of the connected audio device, comprising: an audio CODEC that converts an audio signal based on the determined type of the audio device; and the jack interface. An audio device discrimination method characterized by switching at least a connection state and an input / output level of an audio signal.   17. The audio device determination method according to claim 16, wherein an operation of switching a connection state between the audio CODEC and the jack interface and an input / output level of an audio signal is performed by software control.   A conversion step for converting the impedances of the LEFT channel, RIGHT channel, and MIDDLE channel of the audio device connected to the jack interface into voltage values, and the voltages of the LEFT channel, RIGHT channel, and MIDDLE channel converted by the conversion step, respectively. A comparison step for outputting a result of comparing a value with a preset voltage threshold, and a combination of comparison results with the voltage threshold for each of the LEFT channel, the RIGHT channel, and the MIDDLE channel obtained by the comparison step. 18. The audio device determination method according to claim 16, wherein the type of the connected audio device is determined based on the type.   19. The audio device determination method according to claim 18, wherein the voltage threshold value to be compared with the voltage value of each of the LEFT channel, the RIGHT channel, and the MIDDLE channel can be changed to an arbitrary value by software control.   Based on the comparison result of both the voltage values of the RIGHT channel and the MIDDLE channel and 0 V, whether the audio device plug connected to the jack interface is at least a 2-pole plug, 3-pole plug, or 4-pole plug 20. The audio device determination method according to claim 18 or 19, wherein the determination is performed.   21. The voltage threshold value to be compared with the voltage value of each of the LEFT channel, the RIGHT channel, and the MIDDLE channel can be changed to an arbitrary value by software control. Audio device identification method.   22. An audio device determination program that implements at least a part of the audio device determination method according to claim 16 as a program executable by a computer.   23. A program recording medium, wherein the audio device identification program according to claim 22 is recorded on a computer-readable recording medium.

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