JP3407622B2 - Power supply device for plug - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a plug, which outputs a microphone bias voltage to the plug in response to the insertion of the plug for the microphone, and more particularly, a structure capable of detecting whether or not the plug for the microphone is inserted. And a power supply device for a plug.

[0002]

For example, a mobile phone is provided with a handset for making a hands-free call by using a microphone earphone instead of a handset call state using a built-in microphone and a speaker. There is. In this case, it is necessary to detect whether or not the microphone earphone plug is inserted (connected) and switch the audio input path and the audio output path. For this reason, conventionally, in order to detect the presence or absence of the insertion of the plug, the means shown in FIG. 3 or FIG. 4 has been adopted.

That is, in FIG. 3 showing only the related structure of the mobile phone, the connector device 2 into which the plug 1 for the microphone earphone is inserted and withdrawn is connected to the plug terminals 1a, 1b and 1c according to the insertion of the plug 1. A fixed contact 2a for a microphone, a fixed contact 2b for an earphone, and a common fixed contact 2c. Further, the connector device 2 is provided with an opening / closing contact 2d, and the opening / closing contact 2d always maintains a state of being connected to the fixed contact 2a, and when the microphone earphone plug 1 is inserted, the fixed opening / closing contact 2d is fixed. It is configured to be separated from the contact 2a.

The bias circuit 3 is provided to apply a microphone bias voltage obtained by smoothing the output voltage of the built-in battery 4 to the fixed contact 2a, and includes a capacitor 3a and a resistor 3b.
And 3c in combination, so that it also functions as a filter for noise prevention.

The n-channel MOSFET 5 is provided so as to be turned on / off according to the insertion / removal of the microphone earphone plug 1, and a state in which a microphone bias voltage is applied to its gate through the opening / closing contact 2d and the gate bias resistor 6. Is connected to turn on. In this case, the drain of the FET 5 is connected to the plus side of the built-in battery 4 via the pull-up resistor 7, and the source is connected to the ground terminal.

Therefore, the voltage level of the detection terminal 8 connected to the drain of the FET 5 is determined by the microphone earphone plug 1
Shows a low level when the plug 1 is not inserted (the FET 5 is on), but is inverted to a high level when the plug 1 is inserted (the FET 5 is off), and the plug 1 is inserted based on the level. The presence or absence of can be detected.

However, in such a structure, the current continues to flow even when the mobile phone is in the standby state at all times, and in particular, when the microphone earphone plug 1 is inserted, the microphone bias voltage becomes the side of the plug 1 side. Therefore, a relatively large load current will continue to flow. For this reason, the current consumption increases unnecessarily, the built-in battery 4 is exhausted quickly, and as a result, there arises a problem that the standby time of the mobile phone becomes short.

In order to deal with such a problem, FIG.
, A switching element 9 is interposed between the built-in battery 4 and the bias circuit 3, and the switching element 9
There has been considered a means for turning on the switch at a timing at which it is necessary to detect the insertion state of the plug 1 (a call start timing of the mobile phone, an intermittent timing of a relatively short cycle in the call state).

However, in such a means, since the bias circuit 3 includes the capacitor 3a as a delay element, the plug 1 is turned on after the switching element 9 is turned on.
A relatively long delay time (for example, several hundreds of milliseconds) is required until it becomes possible to detect the presence / absence of insertion, which causes a new problem of unnecessarily long detection time.

The present invention has been made in view of the above circumstances, and an object thereof is to detect the inserted state of a microphone plug at high speed while suppressing current consumption. It is to provide a power supply device for a plug that produces an effect.

[0011]

In order to achieve the above object, means as described in claim 1 can be adopted. According to this means, in the state where the microphone plug is not inserted into the connector device (the opening / closing contact is connected to the first fixed contact), a terminal for giving a voltage output to the bias circuit, A state in which a bias circuit, a first fixed contact, an opening / closing contact, and an impedance element set to have a higher impedance than the bias circuit are connected in series between a check terminal to which a pulsed voltage signal is applied at a predetermined timing. Become.

Therefore, when a pulsed voltage signal is applied to the check terminal when the microphone plug is not inserted, most of the voltage signal is shared by the impedance element set to high impedance. Therefore, the change width of the voltage level of the switching contact becomes relatively small. That is, although the voltage level of the check terminal changes by the width corresponding to the applied voltage signal,
The voltage level of the switching contacts becomes relatively stable. Further, the phenomenon in which the range of change in the voltage level of the switching contacts is suppressed occurs similarly when the microphone bias voltage is output through the bias circuit and when the output is stopped.

On the other hand, when the microphone plug is inserted into the connector device, that is, when the open / close contact is separated from the first fixed contact, the open / close contact is connected to the impedance element at the check terminal. Will be connected via.

Therefore, when a pulsed voltage signal is applied to the check terminal in the inserted state of the microphone plug, the applied voltage is directly applied to the open / close contact through the impedance element. The voltage level changes greatly following the applied voltage.

In short, in the state in which the microphone plug is not inserted in the connector device and in the state in which the microphone plug is inserted, the change state of the voltage level of the switching contact when the pulse voltage signal is applied to the check terminal is changed. As a result, it is possible to reliably determine whether or not the microphone plug is inserted into the connector device based on the change state of the voltage level of the switching contact.

In this case, when detecting the state where the microphone plug is inserted into the connector device, the open / close contact is separated from the first fixed contact, that is, separated from the bias circuit including the delay element. Therefore, the detection speed of the insertion state depends on the cycle of applying the pulsed voltage signal to the check terminal.
Therefore, by shortening the application period, the insertion state of the microphone plug can be detected at high speed. Further, based on such a detection result, the output of the microphone bias voltage through the bias circuit can be stopped, so that a situation in which a large load current continuously flows as in the conventional configuration (see FIG. 3) is obviated. Can be prevented,
Thus, the consumption current can be suppressed.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a mobile phone will be described below with reference to FIGS. In FIG. 1, which shows the configuration of the essential parts, a connector device 11 provided on the mobile phone side is provided with a microphone earphone plug 12 (corresponding to a microphone plug in the present invention) according to the insertion of the plug 12 side. Plug terminal 1
It has first, second and third fixed contacts 11a, 11b and 11c which are respectively connected to 2a, 12b and 12c. Further, the connector device 11 is provided with an opening / closing contact 11d, and the opening / closing contact 11d always maintains a state of being connected to the first fixed contact 11a, and when the microphone earphone plug 12 is inserted, It is configured to be separated from the fixed contact 11a.

The bias circuit 13 is for smoothing the voltage output given through the microphone bias terminal 13a and giving it as a microphone bias voltage to the first fixed contact 11a. The microphone bias terminal 13a and the first fixed contact 11a are also provided. The resistors 13b and 13c are connected in series between them, and the capacitor 13d is connected between the common connection point of the resistors 13b and 13c and the ground terminal.

The resistance 14 corresponding to the impedance element referred to in the present invention has its impedance (resistance value) set to a value sufficiently higher than the impedance of the bias circuit 13, and is composed of the switching contact 11d and the check terminal 15. Is intervened between. The open / close contact 11d is directly connected to the detection terminal 16.

In this case, although not specifically shown, when the microphone earphone plug 12 is inserted into the connector 11, the microphone bias voltage from the bias circuit 13 is the first.
Is output to the microphone earphone plug 12 side through the fixed contact 11a and the second fixed contact 11b, and the reception signal (audio signal) for the earphone is output to the third fixed contact 1
It is output to the microphone earphone plug 12 side through the space between 1c and the second fixed contact 11b.

Now, the portable telephone has the above-mentioned check terminal 1
5, the pulse voltage signal Pv having a higher level than the microphone bias voltage is applied, for example, twice at the call start timing, and the pulse voltage signal Pv is applied twice each in the call state. It is configured to be performed in a cycle. In addition, in the mobile phone, the insertion state of the microphone earphone plug 12 into the connector device 11 is determined based on the voltage level of the detection terminal 16 as described below.
The configuration is used for switching the voice input route and the voice output route.

However, according to the configuration of this embodiment described above, the following actions and effects can be obtained. That is, the microphone earphone plug 12 is not inserted into the connector device 11 (the opening / closing contact 11d is the first
(When it is connected to the fixed contact 11a) of
Between the microphone bias terminal 13a for giving a voltage output to the bias circuit 13 and the check terminal 15 to which the pulsed voltage signal Pv is applied at a predetermined timing, the bias circuit 13, the first fixed contact 11a, and the opening / closing contact. 11
d, and the resistor 14 having a sufficiently higher impedance than the bias circuit 13 is connected in series.

Therefore, when the pulse-shaped voltage signal Pv is applied to the check terminal 14 when the microphone earphone plug 12 is not inserted, most of the voltage signal Pv is the resistance 14 set to high impedance. Since it is shared, the change width of the voltage level of the detection terminal 16 to which the switching contact 11d is connected becomes relatively small. That is, the voltage level of the detection terminal 16 becomes relatively stable even though the voltage level of the check terminal 15 changes by a width corresponding to the applied voltage signal Pv. Further, the phenomenon in which the variation width of the voltage level of the detection terminal 16 is suppressed as described above is as shown in FIGS.
The same occurs when the output of the microphone bias voltage is stopped through the bias circuit 13 (FIG. 2A) and is output (FIG. 2B).

On the other hand, when the microphone / earphone plug 12 is inserted into the connector device 11, that is, when the open / close contact 11d is separated from the first fixed contact 11a, the open / close contact 11d (that is, the open / close contact 11d). Detection terminal 1
6) is connected to the check terminal 15 via the resistor 14.

Therefore, when the microphone earphone plug 12 is inserted, the pulse voltage signal P is applied to the check terminal 15.
When v is applied, the applied voltage Pv is
Since the voltage level is directly applied to the detection terminal 16 through, the voltage level of the detection terminal 16 greatly changes following the applied voltage Pv, as shown in FIG.

In summary, in the state where the microphone earphone plug 12 is not inserted into the connector device 11,
The inserted state is different from the inserted state in the change state of the voltage level of the detection terminal 16 when the pulsed voltage signal Pv is applied to the check terminal 15.
Whether or not the microphone earphone plug 12 is inserted into the connector device 11 can be reliably determined based on the change state of the voltage level of the detection terminal 16.

In this case, when the state in which the microphone earphone plug 12 is inserted into the connector device 11 is detected, the open / close contact 11d is separated from the first fixed contact 11a, that is, the delay element. Since it is separated from the bias circuit 13 including the capacitor 13d,
The insertion state can be detected at high speed.

The microphone earphone plug 1 in the call state
The detection speed of the insertion state of No. 2 depends only on the period of applying the pulsed voltage signal Pv to the check terminal 15. Therefore, by shortening the application cycle,
The insertion state of the microphone earphone plug 12 can be detected at high speed. Further, when the state where the microphone earphone plug 12 is pulled out from the connector device 11 is detected, the opening / closing contact 11d is connected to the first fixed contact, but at this point, the bias circuit 13 Since the capacitor 13d is in a state of being charged by the microphone bias voltage, the detection speed of the extraction state also depends on the cycle of applying the pulse voltage signal Pv to the check terminal 15. Therefore, by shortening the application cycle, it becomes possible to detect the extraction state of the microphone earphone plug 12 at high speed.

Further, based on such a detection result, the output of the microphone bias voltage through the bias circuit 13 can be selectively stopped, so that a situation in which a large load current continuously flows as in the conventional configuration is caused. This can be prevented in advance, and the consumption current can be suppressed.

The present invention is not limited to the above embodiment, but the following modifications or expansions are possible. Although the example applied to the mobile phone has been described, the present invention can also be applied to an audio device or the like. Besides, it can be applied to general devices including at least a microphone plug. In the above-described embodiment, the pulse voltage signal Pv is applied twice to the check terminal 15 in order to improve the accuracy when detecting the presence / absence of the insertion of the microphone earphone plug 12, but it is applied only once. However, the intended purpose can be fully achieved.

[Brief description of drawings]

FIG. 1 is a diagram demonstrating the configuration of essential parts in an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation

FIG. 3 is a view corresponding to FIG. 1 showing a conventional configuration.

FIG. 4 is a view corresponding to FIG. 1 showing a different conventional configuration.

[Explanation of symbols]

11 is a connector device, 11a is a first fixed contact, 11b
Is a second fixed contact, 11c is a third fixed contact, 11d is an opening / closing contact, 12 is a microphone earphone plug (microphone plug), 12a to 12c are plug terminals, 13 is a bias circuit, 13b and 13c are resistors, 13d. Is a capacitor, 14 is a resistor (impedance element), 15 is a check terminal, and 16 is a detection terminal.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H04R 3/00 320 H01R 17/04 510Z (58) Fields investigated (Int.Cl. ⁷ , DB name) H04R 1/04 H01R 13 / 64 H01R 24/02 H04B 7/26 H04M 1/00 H04M 19/08 H04R 1/10 104 H04R 3/00 320

Claims (3)

(57) [Claims] 1. A connector device having first and second fixed contacts, which are connected to a plug for a microphone in response to insertion of the plug, and a microphone bias voltage having a smoothed voltage output. A plug power supply device provided with a bias circuit for outputting through a fixed contact, wherein the plug device is provided in the connector device and is always connected to the bias circuit through the first fixed contact and the microphone plug. The first according to the insertion of
An open / close contact that is separated from the fixed contact, a check terminal to which a pulsed voltage signal is applied at a predetermined timing, and an impedance element that has a higher impedance than the bias circuit and that is interposed between the open / close contact and the check terminal. It is configured to determine whether or not the microphone plug is inserted into the connector device based on a change state of the voltage level of the switching contact when the pulsed voltage signal is applied to the check terminal. A power supply device for a plug characterized by the above. 2. The power supply device for a plug according to claim 1, wherein the bias circuit includes a capacitor and a resistor for smoothing a microphone bias voltage. 3. A built-in mobile phone, wherein the microphone plug is provided as a microphone earphone plug for the mobile phone, and the connector device includes the first and second contact points. In addition, it has a third fixed contact that is connected to the plug according to the insertion of the microphone earphone plug, and outputs a reception signal for the earphone through the third fixed contact and the second fixed contact. It is configured to apply a pulse voltage signal to the check terminal at the call start timing of the mobile phone and to apply the pulse voltage signal at a predetermined cycle in the call state. , The insertion determination result of the plug for the microphone earphone based on the voltage level of the opening and closing contacts, the voice input path and voice for the mobile phone The power supply device for a plug according to claim 1, wherein the power supply device for a plug is configured to be used for switching an output path.