JP2008072569A - Wireless microphone device and portable electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless microphone device which can control the power consumption of a battery when it is not used without making an arrangement complicated. <P>SOLUTION: The wireless microphone device comprises a tact switch 6 outputting a signal which can identify an operation state and a non-operation state, a switch operation detection circuit 15 generating a state signal corresponding to an operation flag inverted based on the output of the switch 6, an FET 13 interrupting a power supply from a converter 12 to a transmission circuit unit 20, and a reverse flow inhibition diode 14 which inhibits a reverse flow from the converter 12 to a battery accommodating portion 17 and supplies a power voltage after boosting having priority over power voltage before boosting to the switch operation detection circuit 15. The switch operation detection circuit 15 generates a state signal composed of a voltage level according to the power voltage supplied. The transmission circuit unit 20 generates an off control signal based on the state signal, and the converter 12 and the FET 13 operate based on the state signal and the off control signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless microphone device and a portable electronic device. More specifically, the present invention relates to an improvement of a wireless microphone device that boosts a power supply voltage of a battery and supplies it to a transmission circuit unit.

  As a wireless microphone device that converts an audio signal from a microphone into an RF (Radio Frequency) signal and transmits the signal wirelessly, a handheld type or a two-piece type is known. The handheld wireless microphone device is a handheld wireless device in which a microphone unit and a transmitter unit are integrated. A two-piece type wireless microphone device is a wireless device in which a microphone unit and a transmitter unit are composed of separate casings, and the microphone unit and the transmitter unit are connected by a flexible transmission cable. This two-piece type microphone device is sometimes called a belt pack type because it can be attached to a waist belt.

  In such a wireless microphone device, a battery is usually used as a power source for supplying power to the microphone and the transmission circuit. Wireless microphone devices are often left unused for a long period of time. In view of this, it is conceivable to suppress the power consumption of the battery when the microphone device is not used, in order to suppress the battery consumption and make the battery last longer. Conventionally, a wireless microphone device has used a toggle switch such as a slide type or a push type to cut off the power supply to a transmission circuit or the like when not in use. This toggle switch is an operation switch that maintains a conductive state between the terminals until the user operates it again, and the ON state is mechanically held.

  In general, a tact switch (registered trademark) is known as a switch used to cut off the power supply, in addition to a toggle switch. This tact switch is an operation switch that conducts between terminals only while the user is operating, and the ON state and the OFF state are held electronically.

  The tact switch is simpler and cheaper than the toggle switch, so it has a high degree of freedom in design and is therefore advantageous for downsizing the wireless microphone device and improving drip-proofness. Conceivable. Therefore, it is conceivable to use a tact switch for a wireless microphone device. However, when using a tact switch, unlike when using a toggle switch, the power consumption of the battery is reduced because it is necessary to maintain the electronic state in an off state even when the power supply to the transmission circuit or the like is interrupted. It will not be zero. For this reason, there was a problem that the power consumption of the battery increased when the microphone device was not used.

  The present invention has been made in view of the above circumstances, and provides a wireless microphone device and a portable electronic device that can easily improve drip-proofness without increasing battery consumption. Objective. In particular, an object of the present invention is to provide a wireless microphone device that can suppress power consumption of a battery when not in use without complicating the configuration. It is another object of the present invention to provide a portable electronic device that suppresses power consumption during standby.

  According to a first aspect of the present invention, there is provided a wireless microphone device that removably accommodates a battery that supplies a first power supply voltage, boosts the first power supply voltage supplied from the battery storage section, and supplies a second power supply voltage. A wireless microphone device including a booster circuit that generates a signal and a transmission circuit unit that is supplied with a second power supply voltage from the booster circuit and converts an audio signal from the sound collecting element into an RF signal, the operation state and non-operation An operation switch that outputs a signal capable of identifying a state, a switch operation detection circuit that holds an operation flag that is inverted based on the output of the operation switch, and generates a state signal having a voltage level according to the operation flag; A switching element that cuts off power supply from the booster circuit to the transmitter circuit unit, and prevents backflow from the booster circuit to the battery housing. To the switch operation detecting circuit, and said second power supply voltage as the power supply voltage and a reverse current preventing diode for supplying by priority than the first power supply voltage. The switch operation detection circuit generates a state signal having a voltage level corresponding to a supplied power supply voltage, and the transmission circuit unit generates an off control signal based on the state signal, and the boost circuit and the switching The element operates based on the state signal and the off control signal.

  In this wireless microphone device, the second power supply voltage after boosting is given priority over the first power supply voltage before boosting as a power supply voltage for the switch operation detection circuit that holds the operation flag that is inverted based on the state transition of the operation switch. Supplied. That is, if both the first power supply voltage and the second power supply voltage can be supplied, the second power supply voltage is supplied to the switch operation detection circuit. On the other hand, when the switching element is cut off or the second power supply voltage cannot be supplied because the booster circuit has finished the boosting process, the first power supply voltage is supplied to the switch operation detection circuit. The operation flag is inverted based on one or both of the state transition from the non-operation state to the operation state of the operation switch and the state transition from the operation state to the non-operation state. In the switch operation detection circuit, the voltage level changes according to such an operation flag, and a state signal whose voltage level changes according to the supplied power supply voltage is generated. In the transmission circuit unit, an off control signal is generated based on such a status signal, and in the booster circuit and the switching element, an operation is performed based on the status signal and the off control signal.

  Since the voltage level of the status signal generated by the switch operation detection circuit changes according to the power supply voltage supplied to the switch operation detection circuit, the voltage level is automatically boosted as the power supply voltage supplied is boosted. The Rukoto. Therefore, when the switching element is in the cut-off state or the boosting circuit has finished the boosting process, the operation switch is operated when the operation switch is operated while driving the switch operation detection circuit with the power supply voltage before boosting. The step-up circuit and the switching element can be operated by correctly detecting the operation.

  In addition, when the booster circuit starts the boosting process and the switching element is in a conductive state, the state signal is boosted along with the boost of the power supply voltage supplied to the switch operation detection circuit. The transmission circuit unit that operates with the boosted power supply voltage can be correctly operated based on the status signal. In particular, when the switching element is in a conductive state, it is possible to correctly detect a change in the voltage level of the state signal due to operation of the operation switch when the operation switch is operated, so that an off control signal is generated appropriately. Can be made.

  In addition, the backflow prevention diode is used to prevent backflow from the booster circuit to the battery housing portion, and the power supply voltage after boosting is supplied to the switch operation detection circuit with priority over the power supply voltage before boosting. Therefore, the configuration of the switch operation detection circuit can be simplified as compared with the case where the power supply voltage after boosting and the power supply voltage before boosting are separately supplied. With such a configuration, when the switching element is in the conductive state, the switch operation detection circuit is driven by the power supply voltage before boosting when the transmission circuit unit is operated properly and in the cut-off state. Therefore, it is possible to suppress battery power consumption when the microphone device is not used.

  In addition to the above-described configuration, the wireless microphone device according to a second aspect of the present invention is configured so that the transmission circuit unit generates an off control signal based on a state signal when the switching element is in a conductive state, and the switching element However, when the state signal changes, the power supply is switched from the cut-off state to the conductive state, and when the off-control signal changes, the switch is switched from the conductive state to the cut-off state. According to such a configuration, since the off control signal is generated based on the state signal when the switching element is in the conductive state, the off control signal is correctly detected by detecting the change of the state signal due to the operation of the operation switch. Can be generated, and the switching element in the conductive state can be appropriately turned off.

  In a wireless microphone device according to a third aspect of the present invention, in addition to the above configuration, the booster circuit starts the boosting process of the first power supply voltage when the state signal changes, and performs the boosting process when the off control signal changes. Configured to finish. According to such a configuration, a change in the state signal due to the operation of the operation switch is correctly detected and an off control signal is generated, so that the conductive switching element can be appropriately turned off and the booster circuit is also appropriate. Can be terminated. Therefore, it is possible to further suppress the power consumption of the battery when the power is turned off while appropriately operating when the power is turned on.

  In a wireless microphone device according to a fourth aspect of the present invention, in addition to the above configuration, the operation switch is provided on the cathode side of the backflow prevention diode, and the switch operation detection circuit includes a power supply terminal, an output terminal, and a clock terminal. The power supply terminal is supplied with a second power supply voltage from the booster circuit via the switching element and a first power supply voltage from the battery via the backflow prevention diode. A detection signal having a different voltage level is supplied to the clock terminal in accordance with the state of the operation switch, and the output terminal is an output whose voltage level is switched in synchronization with either rising or falling of the detection signal. The terminal is configured to output a signal as the state signal.

  In this wireless microphone device, detection signals having different voltage levels according to the state of the operation switch are supplied to a clock terminal of a flip-flop circuit as a switch operation detection circuit, and used as a clock to generate a state signal. According to such a configuration, it is possible to cause one flip-flop circuit to generate a state signal in which the voltage level changes according to the power supply voltage supplied to the power supply terminal and the voltage level changes according to the operation of the operation switch. . Therefore, the battery power consumption when not in use can be effectively suppressed without complicating the configuration of the switch operation detection circuit.

  In the wireless microphone device according to a fifth aspect of the present invention, in addition to the above configuration, the transmission circuit unit synthesizes a tone circuit that generates a tone signal composed of a predetermined frequency signal, the audio signal, and the tone signal. An audio circuit that generates a signal; a transmission circuit that converts the synthesized signal into the RF signal; and a microprocessor that generates the off-control signal based on the status signal and generates a generation request for the tone signal The tone circuit generates the tone signal based on the generation request from the microprocessor, and the microprocessor outputs the generation request to the tone circuit when the power is turned off. Is output to the booster circuit and the switching element. According to such a configuration, since the booster circuit and the switching element can be turned off after the tone signal is transmitted, it is possible to suppress the output of noise on the receiver side when the transmission circuit is turned off. it can.

  According to a sixth aspect of the present invention, there is provided a portable electronic device that detachably houses a battery for supplying a first power supply voltage, boosts the first power supply voltage supplied from the battery housing section, An electronic switch having a booster circuit for generating a power supply voltage and a microprocessor to which a second power supply voltage is supplied from the booster circuit, and an operation switch for outputting a signal capable of identifying an operation state and a non-operation state; A switch operation detection circuit that retains an operation flag that is inverted based on the output of the operation switch and generates a status signal having a voltage level corresponding to the operation flag, and cuts off power supply from the booster circuit to the microprocessor And the second power supply voltage as a power supply voltage with respect to the switch operation detection circuit. Configured with a blocking diode for supplying by priority than the first power supply voltage. The switch operation detection circuit generates a status signal having a voltage level corresponding to a supplied power supply voltage, and the microprocessor generates an off control signal based on the status signal, and the booster circuit and the switching element Operates based on the status signal and the off control signal.

  According to the wireless microphone device and the portable electronic device of the present invention, when the switching element is in the conductive state, the transmitter circuit unit is appropriately operated, and when the switching element is in the cut-off state, Since the switch operation detection circuit is driven by the power supply voltage, battery power consumption when the microphone device is not used can be suppressed. In addition, the backflow prevention diode is used to prevent backflow from the booster circuit to the battery housing portion, and the power supply voltage after boosting is supplied to the switch operation detection circuit with priority over the power supply voltage before boosting. Therefore, the configuration of the switch operation detection circuit can be simplified as compared with the case where the power supply voltage after boosting and the power supply voltage before boosting are separately supplied. Therefore, it is possible to suppress the power consumption of the battery when not in use without complicating the configuration, and to realize a wireless microphone device that can easily improve the drip-proof property without increasing battery consumption. it can.

  FIG. 1 is an external view showing an example of a schematic configuration of a wireless microphone device according to an embodiment of the present invention, and shows a handheld microphone device 1. The microphone device 1 includes a wind screen 2 that houses a microphone 4 and a transmitter body 3. The wind screen 2 is a spherical wind shield made of a member such as a fine wire mesh, and prevents the microphone 4 from picking up noise caused by the wind.

  The transmitter main body 3 is composed of a vertically long cylindrical casing, and a circuit board 5 on which the power supply circuit unit 10 and the transmission circuit unit 20 are provided is accommodated in the casing. A tact switch 6 for turning on / off the power supply is provided on the bottom surface of the casing of the transmitter body 3. When the microphone device 1 is used, the transmitter main body 3 is held by hand.

  The microphone 4 is a sound collection element that converts sound input from the outside into an electric signal and generates a sound signal. The transmission circuit unit 20 is a circuit unit for converting an audio signal input from the microphone 4 into an RF signal and transmitting the RF signal. The power supply circuit unit 10 is a circuit unit for boosting the power supply voltage of the battery and supplying it to the transmission circuit unit 20.

  The circuit board 5 is formed of a multilayer board on which a conductive layer and a wiring layer are formed with an insulating layer interposed therebetween. This conductive layer is a layer made of a conductor that conducts electricity, and is a ground (GND) layer for grounding a circuit element provided on the circuit board 5 or a power supply layer for supplying power to the circuit element. Used as The wiring layer is a layer made of a wiring pattern for electrically connecting circuit elements, and is formed on the substrate surface. Here, it is assumed that the conductive layer of the circuit board 5 is used as a ground layer and as an antenna element of a dipole antenna for transmitting an RF signal.

  The tact switch 6 is an operation switch that outputs a signal that can distinguish between an operation state and a non-operation state, and is turned on only while the user is operating. The operation state is a state in which the user is operating the tact switch 6, and the transition from the non-operation state to the operation state is performed by the user's operation. In contrast, the operation state automatically transitions to the non-operation state. For example, the tact switch 6 is composed of two terminals and a movable part that can conduct between the terminals. By operating the movable part, the terminals are electrically connected, and the movable part automatically returns to its original position when not operated. Configured to return.

  Here, it is assumed that a push button type switch having a drip-proof property for conducting between terminals during operation is used as the tact switch 6.

  FIG. 2 is a block diagram showing a configuration example of the transmission circuit unit 20 in the microphone device 1 of FIG. The transmission circuit unit 20 includes a tone circuit 21, an audio circuit 22, a transmission circuit 23, and a microprocessor 24. The tone circuit 21 is a circuit for generating a tone signal composed of a predetermined frequency signal. The tone signal is one or more frequency signals transmitted in addition to the audio signal so that the receiver side can detect the end of transmission when the microphone device 1 is powered off.

  Here, a frequency signal different from the frequency band of the audio signal, for example, a signal having a frequency of 32.768 kHz (kilohertz) is added to the audio signal as a tone signal.

  The audio circuit 22 is a circuit for synthesizing the audio signal from the microphone 4 and the tone signal from the tone circuit 21 to generate a synthesized signal. The transmission circuit 23 is a modulation circuit for converting the synthesized signal from the audio circuit 22 into an RF signal, and includes, for example, a VCO, a PLL, and an amplifier.

  A VCO (Voltage Controlled Oscillator) is an oscillator that oscillates in response to a change in voltage level, and generates a predetermined frequency signal. A PLL (Phase Locked Loop) is an electronic circuit that adjusts the oscillation frequency of the VCO to keep the frequency of the output signal constant. The amplifier is a circuit element that amplifies the power of the modulated RF signal.

  The RF signal generated by the transmission circuit 23 is supplied to the ground layer of the circuit board 5 functioning as an antenna element and transmitted. Power is supplied from the power supply circuit unit 10 to the tone circuit 21, the audio circuit 22, and the transmission circuit 23 via the microprocessor 24.

  The microprocessor 24 is a circuit element made of a semiconductor chip that is supplied with power from the power supply circuit unit 10 and detects the operation of the tact switch 6 to perform power-off control. This power-off control generates a tone signal generation request, cuts off power supply to the tone circuit 21, audio circuit 22, and transmission circuit 23, and causes the power supply circuit unit 10 to stop power supply. Is output.

  The ground terminal of the microprocessor 24 is connected to the ground layer of the circuit board 5. The tone circuit 21 generates a tone signal based on a generation request from the microprocessor 24.

  In the power-off control by the microprocessor 24, when the power is turned off, the power supply to the tone circuit 21, the audio circuit 22, and the transmission circuit 23 is cut off, and then an off control signal is output. At this time, from the viewpoint of preventing noise from being output on the receiver side when the transmission circuit 23 is turned off, after the tone signal generation request is output to the tone circuit 21, the DC-DC converter 12 and It is desirable to output an off control signal to the FET 13.

  FIG. 3 is a circuit diagram illustrating a configuration example of a main part of the microphone device 1 of FIG. 1, in which the power supply circuit unit 10 is illustrated. The power supply circuit unit 10 includes a battery 11, a DC-DC converter 12, an FET 13, a backflow prevention diode 14, a switch operation detection circuit 15, an OR circuit 16, and a battery housing portion 17.

  The battery 11 is a power supply device that supplies a first power supply voltage, and is detachably accommodated in the battery accommodating portion 17. Here, one battery (primary battery) having an electromotive force of 1.5 V (volts) is used as the battery 11. The negative electrode of the battery 11 is connected to the ground layer of the circuit board 5, and the positive electrode is connected to the DC-DC converter 12 and the backflow prevention diode 14.

  The DC-DC converter 12 is a booster circuit that boosts the first power supply voltage supplied from the battery 11 and generates a second power supply voltage, and performs a process of converting a DC voltage into a DC voltage having a different voltage level. . Here, it is assumed that the first power supply voltage (1.5 V) is boosted to 3.0 V and output as the second power supply voltage. The ground terminal of the DC-DC converter 12 is connected to the ground layer of the circuit board 5.

  In the DC-DC converter 12, an oscillation circuit that oscillates by feeding back a part of the output, and a semiconductor for rectifying a high-voltage pulsating current obtained by the oscillation circuit and obtaining a signal on the plus side only. A diode and an LC filter circuit for rectifying this signal to obtain a direct current output are provided.

  An FET (Field Effect Transistor) 13 is a switching element for cutting off power supply from the DC-DC converter 12 to the transmission circuit unit 20, and has a source terminal, a drain terminal, and a gate terminal. The source terminal of the FET 13 is connected to the DC-DC converter 12, and the drain terminal is an output terminal for outputting a power supply voltage to the transmission circuit unit 20. The gate terminal is connected to the output terminal of the OR circuit 16. The FET 13 prevents the power supply voltage from being supplied from the battery 11 to the transmission circuit unit 20 via the semiconductor diode in the DC-DC converter 12 when the power is off.

  The backflow prevention diode 14 prevents backflow from the DC-DC converter 12 to the battery 11 and supplies the second power supply voltage as a power supply voltage with priority over the first power supply voltage to the switch operation detection circuit 15. Circuit element. That is, if both the first power supply voltage and the second power supply voltage can be supplied, the second power supply voltage is supplied to the switch operation detection circuit 15. On the other hand, if the FET 13 is cut off and the second power supply voltage cannot be supplied, the first power supply voltage is supplied to the switch operation detection circuit 15.

  As such a backflow prevention diode 14, for example, a PN junction type semiconductor diode is used. The positive electrode of the battery 11 and the input terminal of the DC-DC converter 12 are connected to the anode (anode) side of the backflow prevention diode 14, and the output terminal of the DC-DC converter 12 is connected to the cathode (cathode) side via the FET 13. Yes. That is, the backflow prevention diode 14 prevents the boosted power supply voltage from being supplied from the DC-DC converter 12 to the positive electrode of the battery 11 via the FET 13.

  The switch operation detection circuit 15 is a circuit for holding an operation flag that is inverted based on the state transition of the tact switch 6 and generating a state signal having a voltage level corresponding to the operation flag. This operation flag is a flag that is reversed based on one or both of the state transition of the tact switch 6 from the non-operation state to the operation state and / or the state transition from the operation state to the non-operation state. The ground terminal of the switch operation detection circuit 15 is connected to the ground layer of the circuit board 5, and a state signal having a voltage level corresponding to the power supply voltage supplied from the battery 11 and the DC-DC converter 12 is generated.

  Here, the tact switch 6 is provided on the cathode side of the backflow prevention diode 14, and the boosted power supply voltage is supplied from the DC-DC converter 12 via the FET 13 between the backflow prevention diode 14 and the tact switch 6. To do. The tact switch 6 is connected to the ground layer of the circuit board 5 through the resistance element R, and switch operation detection signals having different voltage levels are supplied to the switch operation detection circuit 15 according to the state of the tact switch 6. And

  In this example, the input terminal of the detection signal in the switch operation detection circuit 15 is connected between the tact switch 6 and the resistance element R. When the tact switch 6 changes from the non-operation state to the operation state, the switch operation is performed. The voltage level of the detection signal changes from the low level to the high level. On the other hand, when the state of the tact switch 6 is changed from the operation state to the non-operation state, the voltage level of the switch operation detection signal changes from the high level to the low level.

  The state signal generated by the switch operation detection circuit 15 is switched between a high level and a low level every time the tact switch 6 is operated, and the voltage level changes depending on the supplied power supply voltage. It is a voltage signal. The status signal generated in the switch operation detection circuit 15 is output to the OR circuit 16 and the microprocessor 24.

  In the microprocessor 24, an off control signal having a voltage level corresponding to the voltage level of the state signal from the switch operation detection circuit 15 is generated and output to the OR circuit 16.

  The OR circuit 16 is a logic circuit that outputs a logical sum of the status signal from the switch operation detection circuit 15 and the off control signal from the microprocessor 24 to the DC-DC converter 12 and the FET 13. Specifically, when the voltage level of either the status signal or the off control signal is high, a high level voltage signal is output. On the other hand, when the voltage levels of the status signal and the off control signal are both low, a low level voltage signal is output.

  The DC-DC converter 12 operates based on the state signal supplied from the switch operation detection circuit 15 via the OR circuit 16, and the operation of starting the power supply voltage boosting process is performed when the state signal changes. This boosting process is terminated when the off control signal supplied from the microprocessor 24 via the OR circuit 16 changes.

  Further, the FET 13 operates based on the state signal supplied from the switch operation detection circuit 15 and performs an operation of transitioning from a power supply cutoff state to a conduction state when the state signal changes. The transition from the conductive state to the cut-off state is performed when the OFF control signal supplied from the microprocessor 24 via the OR circuit 16 changes. The microprocessor 24 monitors a state signal when the FET 13 is in a conductive state, and generates an off control signal when the voltage level changes.

  FIG. 4 is a diagram showing a configuration example of the switch operation detection circuit 15 in the power supply circuit unit 10 of FIG. The switch operation detection circuit 15 includes a Schmitt trigger 31 and a flip-flop circuit 32 having a power supply terminal (VCC), an output terminal Q, a clock terminal (CLK), a D terminal, an inversion terminal of Q, and a ground terminal (GND). Become.

  The Schmitt trigger circuit 31 is a logic circuit having two different input thresholds, and can shape the waveform of the switch operation detection signal supplied from the tact switch 6 into a square wave. The Schmitt trigger circuit 31 holds two input threshold values, an upper limit value and a lower limit value, and generates output signals having different voltage levels according to the comparison result between the input voltage from the tact switch 6 and these threshold values. . Specifically, when the input voltage exceeds the upper limit value from the lower side, the voltage level of the output signal changes from the low level to the high level. Further, when the input voltage exceeds the lower limit value from the higher one, the voltage level of the output signal changes from the high level to the low level.

  The power supply terminal of the flip-flop circuit 32 is supplied with the second power supply voltage from the DC-DC converter 12 via the FET 13 and is supplied with the first power supply voltage from the battery 11 via the backflow prevention diode 14.

  Switch operation detection signals having different voltage levels according to the state of the tact switch 6 are supplied to the clock terminal as a clock. The inverted signal of the output terminal Q is input from the inverting terminal to the D terminal. The ground terminal is connected to the ground layer.

  The output terminal Q is a terminal for outputting an output signal whose voltage level is switched in synchronization with either the rising or falling edge of the switch operation detection signal as a status signal, and the output signal is output to the OR circuit 16 and the microprocessor 24. Is done. Here, it is assumed that a state signal synchronized with the rise of the switch operation detection signal is output from the output terminal Q.

  FIG. 5 is a timing chart showing an example of the operation in the power supply circuit unit 10 of FIG. First, when the tact switch 6 is operated when the power is turned off and the switch shifts from the non-operating state to the operating state, the voltage level of the switch operation detection signal is switched from the low level (0 V) to the high level (1.5 V). The voltage level of the state signal is switched from the low level to the high level in synchronization with the rise of the switch operation detection signal. At this time, the voltage level of the output signal of the OR circuit 16 is switched from the low level to the high level, and the DC-DC converter 12 and the FET 13 are turned on.

  When the tact switch 6 shifts from the operation state to the non-operation state, the voltage level of the switch operation detection signal is switched from the high level to the low level. When the power supply voltage is boosted from 1.5V to 3.0V after a time lag of time A1 from the rise of the switch operation detection signal, the voltage level of the state signal is boosted, and the voltage level of the output signal of the OR circuit 16 is also boosted. Is done.

  The microprocessor 24 is activated by the supply of the boosted power supply voltage, and switches the voltage level of the off control signal from the low level to the high level after a time lag of time A2 from the boosting of the state signal.

  Next, when the tact switch 6 is operated when the power is turned on and the switch shifts from the non-operating state to the operating state, the voltage level of the switch operation detection signal is changed from the low level (0V) to the high level (3.0V). Is switched. In synchronization with the rise of the switch operation detection signal, the voltage level of the state signal is switched from the high level to the low level. The microprocessor 24 detects a change in the voltage level in this state signal, and switches the voltage level of the off control signal from the high level to the low level through a time lag of time A3 from the rise of the switch operation detection signal.

  When the voltage level of the off control signal output from the microprocessor 24 is switched from the high level to the low level, the voltage level of the output signal of the OR circuit 16 is switched from the high level to the low level, and the DC-DC converter 12 and the FET 13 are switched. Turns off.

  Steps S101 to S108 in FIG. 6 are flowcharts illustrating an operation example when the power is turned on in the microphone device 1 in FIG. First, when the tact switch 6 is operated, the voltage level of the state signal is switched based on this switch operation (steps S101 and S102). In synchronization with the change in the voltage level of the state signal, the DC-DC converter 12 and the FET 13 are turned on, the power supply voltage is boosted, and the boosted power supply voltage is supplied to the transmission circuit unit 20 (step S103).

  Next, the microprocessor 24 is activated by supplying the boosted power supply voltage, generates an OFF control signal, and starts supplying power to the tone circuit 21, the audio circuit 22, and the transmission circuit 23 in the transmission circuit unit 20. (Steps S104 and S105). Next, a process of initializing the PLL of the transmission circuit 23 is performed, and a transmission frequency is set for the PLL (steps S106 and S107). When the setting of the PLL is completed, the audio circuit 22 is turned on and an audio signal is transmitted (step S108).

  Steps S201 to S209 in FIG. 7 are flowcharts showing an operation example when the power is off in the microphone device 1 in FIG. First, when the tact switch 6 is operated, the voltage level of the state signal is switched based on this switch operation (steps S201 and S202). The microprocessor 24 detects a change in the voltage level of the state signal and outputs a tone signal generation request to the tone circuit 21 (steps S203 and S204).

  The tone circuit 21 generates a tone signal based on the generation request from the microprocessor 24 and outputs it to the audio circuit 22 (step S205). Next, when the tone signal is transmitted, the microprocessor 24 cuts off the power supply to the tone circuit 21 and turns off the tone circuit 21 (step S206). After the tone circuit 21 is turned off, the power supply to the audio circuit 22 and the transmission circuit 23 is also cut off and turned off (step S207).

  Next, the microprocessor 24 turns off the tone circuit 21, the audio circuit 22, and the transmission circuit 23, then switches the voltage level of the off control signal, and turns off the DC-DC converter 12 and the FET 13 (steps S208 and S209). .

  According to the present embodiment, when the FET 13 is in the cut-off state, the switch operation detection circuit 15 is driven with the power supply voltage before boosting, and the switch operation is correctly detected when the tact switch 6 is operated. Thus, the DC-DC converter 12 and the FET 13 can be operated. Further, when the DC-DC converter 12 starts the boosting process and the FET 13 is in a conductive state, the state signal is boosted along with the boosting of the power supply voltage supplied to the switch operation detection circuit 15. The transmission circuit unit 20 that operates with the power supply voltage boosted by the DC-DC converter 15 can be correctly operated based on the status signal.

  Further, the backflow prevention diode 14 is used to prevent backflow from the DC-DC converter 12 to the battery 11, and the switch operation detection circuit 15 is given priority over the power supply voltage after boosting over the power supply voltage before boosting. Since the voltage is supplied, the configuration of the switch operation detection circuit 15 can be simplified as compared with the case where the power supply voltage after boosting and the power supply voltage before boosting are separately supplied. With such a configuration, when the FET 13 is in a conductive state, the switch operation detection circuit 15 is driven by the power supply voltage before boosting when the transmission circuit unit 20 is appropriately operated and in the cut-off state. Therefore, the power consumption of the battery 11 when the microphone device 1 is not used can be suppressed.

  In this embodiment, an example in which the present invention is applied to a handheld wireless microphone device has been described. However, the present invention is not limited to this, and the present invention is also applied to a two-piece wireless microphone device. be able to. Further, when the present invention is applied to a small portable electronic device that houses a battery, an electronic device in which power consumption during standby can be suppressed can be obtained.

1 is an external view showing an example of a schematic configuration of a wireless microphone device according to an embodiment of the present invention, in which a handheld microphone device 1 is shown. FIG. 2 is a block diagram illustrating a configuration example of a transmission circuit unit 20 in the microphone device 1 of FIG. 1. FIG. 2 is a circuit diagram illustrating a configuration example of a main part of the microphone device 1 of FIG. 1, in which a power supply circuit unit 10 is illustrated. FIG. 4 is a diagram illustrating a configuration example of a switch operation detection circuit 15 in the power supply circuit unit 10 of FIG. 3. 4 is a timing chart showing an example of operation in the power supply circuit unit 10 of FIG. 3. 3 is a flowchart illustrating an operation example when the power is turned on in the microphone device 1 of FIG. 1. 3 is a flowchart illustrating an operation example when the power is off in the microphone device 1 of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microphone apparatus 2 Wind screen 3 Transmitter main body 4 Microphone 5 Circuit board 6 Tact switch 10 Power supply circuit unit 11 Battery 12 DC-DC converter 13 FET
14 Backflow prevention diode 15 Switch operation detection circuit 16 OR circuit 17 Battery housing part 20 Transmission circuit unit 21 Tone circuit 22 Audio circuit 23 Transmission circuit 24 Microprocessor 31 Schmitt trigger circuit 32 Flip-flop circuit

Claims (6)

A battery accommodating portion for detachably accommodating a battery for supplying the first power supply voltage;
A booster circuit that boosts the first power supply voltage supplied from the battery housing unit and generates a second power supply voltage;
A wireless microphone device having a transmission circuit unit that is supplied with a second power supply voltage from the booster circuit and converts an audio signal from the sound collection element into an RF signal;
An operation switch that outputs a signal that can identify an operation state and a non-operation state;
A switch operation detection circuit that holds an operation flag that is inverted based on the output of the operation switch and generates a state signal having a voltage level corresponding to the operation flag;
A switching element for cutting off power supply from the booster circuit to the transmission circuit unit;
A backflow prevention diode for preventing backflow from the booster circuit to the battery housing portion and supplying the second power supply voltage as a power supply voltage with priority over the first power supply voltage to the switch operation detection circuit; With
The switch operation detection circuit generates a status signal having a voltage level corresponding to a supplied power supply voltage,
The transmission circuit unit generates an off control signal based on the state signal,
The wireless microphone device, wherein the booster circuit and the switching element operate based on the state signal and the off control signal. The transmission circuit unit generates an off control signal based on a state signal when the switching element is in a conductive state,
2. The wireless microphone according to claim 1, wherein the switching element transitions from a power supply cutoff state to a conduction state when a state signal changes, and transitions from the conduction state to a cutoff state when the off control signal changes. apparatus.   3. The wireless microphone device according to claim 2, wherein the booster circuit starts boosting the first power supply voltage when the state signal changes, and ends the boosting process when the off control signal changes. The operation switch is provided on the cathode side of the backflow prevention diode;
The switch operation detection circuit comprises a flip-flop circuit having a power supply terminal, an output terminal and a clock terminal,
The power supply terminal is supplied with the second power supply voltage from the booster circuit through the switching element, and is supplied with the first power supply voltage from the battery through the backflow prevention diode,
The clock terminal is supplied with detection signals having different voltage levels according to the state of the operation switch,
3. The terminal according to claim 1, wherein the output terminal is a terminal that outputs, as the state signal, an output signal whose voltage level is switched in synchronization with either a rising edge or a falling edge of the detection signal. Wireless microphone device. A tone circuit for generating a tone signal composed of a predetermined frequency signal by the transmission circuit unit;
An audio circuit for synthesizing the audio signal and the tone signal to generate a synthesized signal;
A transmission circuit for converting the combined signal into the RF signal;
The off control signal is generated based on the status signal, and the microprocessor generates a tone signal generation request.
The tone circuit generates the tone signal based on the generation request from the microprocessor;
3. The wireless microphone according to claim 1, wherein the microprocessor outputs the generation request to the tone circuit when the power is off, and then outputs the off control signal to the booster circuit and the switching element. 4. apparatus. A battery accommodating portion for detachably accommodating a battery for supplying the first power supply voltage;
A booster circuit that boosts the first power supply voltage supplied from the battery housing unit and generates a second power supply voltage;
In a portable electronic device having a microprocessor to which a second power supply voltage is supplied from the booster circuit,
An operation switch that outputs a signal that can identify an operation state and a non-operation state;
A switch operation detection circuit that holds an operation flag that is inverted based on the output of the operation switch and generates a state signal having a voltage level corresponding to the operation flag;
A switching element for cutting off power supply from the booster circuit to the microprocessor;
A backflow prevention diode for preventing backflow from the booster circuit to the battery housing portion and supplying the second power supply voltage as a power supply voltage with priority over the first power supply voltage to the switch operation detection circuit; With
The switch operation detection circuit generates a status signal having a voltage level corresponding to a supplied power supply voltage,
The microprocessor generates an off control signal based on the status signal,
The step-up circuit and the switching element operate based on the state signal and the off control signal.

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