JP7343379B2 - Sound alarm device, movement and clock - Google Patents

Description

The present invention relates to a sound alarm device, a movement, and a timepiece.

Conventionally, due to the high internal resistance of the battery, if the alarm sound and the motor drive timing overlap, priority is given to the motor drive to avoid simultaneous drive, suppress the drop in battery voltage, and prevent electronic clock malfunctions. A technique for realizing this is known (for example, see Patent Document 1). Furthermore, a technique is known in which the alarm driver is switched to low consumption operation when the voltage decreases due to battery life (for example, see Patent Document 2).

Japanese Unexamined Patent Publication No. 56-4086 Japanese Patent Application Publication No. 2007-132788

Here, it is known that the internal resistance of a battery increases as it deteriorates over time, and may be several kilohms at low temperatures, for example. According to the conventional technology described in Patent Document 1, when the timing of the warning sound and the timing of the motor drive overlap, priority is given to the motor drive. For example, if the movement of the chronograph hand of a running watch and the timing of the pitch tone signal overlap, priority is given to motor drive, which disrupts the pitch tone period and reduces functionality. If the internal resistance of the primary battery has increased due to aging and the alarm circuit is operated while the motor is being driven, the battery voltage may drop due to the rush current and fall below the lower limit of the operating voltage of the control means and pointer motor. There is sex. Therefore, other circuits connected to the battery may malfunction.
According to the conventional technology described in Patent Document 2, by switching the alarm driver to low consumption operation, it is possible to suppress a drop in battery voltage even when the motor is being driven, but it is possible to avoid a drop in the sound pressure of the alarm. That is difficult.

The present invention was made in view of the above situation, and an object of the present invention is to provide a sound alarm device, a movement, and a timepiece that can suppress a voltage drop in a battery.

A sound alarm device according to one aspect of the present invention includes a piezoelectric buzzer including a first terminal and a second terminal connected to a positive electrode of a power source, one end of which is connected to the first terminal of the piezoelectric buzzer, and the other end of which is connected to the first terminal of the piezoelectric buzzer. includes a coil connected to the second terminal of the piezoelectric buzzer, a negative terminal, and a positive terminal connected to the second terminal of the piezoelectric buzzer, and is charged with power supplied from the power source. a switch that switches at least a connection state between a capacitor, the first terminal of the piezoelectric buzzer, and a negative terminal of the capacitor to either a conductive state in which current flows or a non-conductive state in which current does not flow; and the switch; an alarm signal generation unit that controls the connection state of the terminal to a conductive state and a non-conductive state at a predetermined frequency; an input terminal connected to the negative terminal of the capacitor; and an output terminal connected to the negative terminal of the power supply. and a current control section having a predetermined resistance component, the current control section changing the connection state between the input terminal and the output terminal into a conductive state where current flows and a non-conductive state where no current flows. a second switch different from the switch that switches at least one of the above, and a sound alarm power supply control unit that charges the capacitor with the power of the power supply by controlling the connection state of the second switch to a conductive state. Be prepared .

In the sound alarm device according to one aspect of the present invention, the current control unit sets the connection state between the input terminal and the output terminal to either a conductive state where current flows or a non-conductive state where current does not flow. The alarm power supply control unit further includes a third switch different from the second switch that switches at least, and the alarm power supply control unit charges the capacitor with the power of the power supply by controlling the third switch to be in a conductive state. The second switch may be controlled to be in a conductive state in a state where power is being charged .

A sound alarm device according to one aspect of the present invention includes a piezoelectric buzzer including a first terminal and a second terminal connected to a positive electrode of a power source, one end of which is connected to the first terminal of the piezoelectric buzzer, and the other end of which is connected to the first terminal of the piezoelectric buzzer. includes a coil connected to the second terminal of the piezoelectric buzzer, a negative terminal, and a positive terminal connected to the second terminal of the piezoelectric buzzer, and is charged with power supplied from the power source. a switch that switches at least a connection state between a capacitor, the first terminal of the piezoelectric buzzer, and a negative terminal of the capacitor to either a conductive state in which current flows or a non-conductive state in which current does not flow; and the switch; an alarm signal generation unit that controls the connection state of the terminal to a conductive state and a non-conductive state at a predetermined frequency; an input terminal connected to the negative terminal of the capacitor; and an output terminal connected to the negative terminal of the power supply. and a current control unit having a predetermined resistance component, a second input terminal connected to the negative terminal of the capacitor, and a second output terminal connected to the negative terminal of the power supply, The continuous sound control unit further includes a continuous sound control unit that switches at least a connection state between the second input terminal and the second output terminal to either a conductive state in which a current flows or a non-conductive state in which a current does not flow. The unit controls the connection state between the second input terminal and the second output terminal to be in a conductive state when the alarm signal generation unit controls the switch at a predetermined frequency for a predetermined time or more.

In the sound alarm device according to one aspect of the present invention, a resistance value of a resistance component included in the current control section may be larger than an internal resistance value of the power source.

In the sound alarm device according to one aspect of the present invention, the capacitor may be a tantalum capacitor.

The movement according to one aspect of the present invention may include the above-described sound alarm device.

A timepiece according to one aspect of the present invention may include the movement described above.

According to the present invention, it is possible to provide a sound alarm device, a movement, and a timepiece that can suppress battery voltage drop.

1 is a diagram illustrating an example of the functional configuration of a timepiece according to the present embodiment. It is a figure showing an example of the functional composition of the alarm part concerning this embodiment. It is a figure showing an example of the functional composition of the alarm part in a 1st embodiment. It is a figure which shows an example of the functional structure of the sound alarm part in 2nd Embodiment. It is a figure which shows an example of the functional structure of the sound alarm part in 3rd Embodiment. FIG. 3 is a diagram for explaining pitch sounds and continuous sounds according to the present embodiment. It is a figure which shows an example of the functional structure of the sound alarm part in 4th Embodiment. FIG. 6 is a diagram for explaining the state of each switch, the potential of a capacitor, and the driving state of a motor when a pitch tone alarm is sounded according to the present embodiment. FIG. 6 is a diagram for explaining the states of each switch and the potential of a capacitor during continuous tone alerting according to the present embodiment. FIG. 3 is a diagram for explaining a voltage drop in the power supply voltage according to the present embodiment. FIG. 2 is a diagram showing an example of a functional configuration in a conventional example. FIG. 3 is a diagram for explaining a voltage drop in a power supply voltage in a conventional example.

[Functional configuration of watch 1]
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing an example of the functional configuration of a timepiece 1 according to the present embodiment. In this embodiment, an analog electronic timepiece will be described as an example of the timepiece 1.

As shown in FIG. 1, the timepiece 1 includes a battery 2, an oscillation circuit 3, a frequency dividing circuit 4, a timepiece control section 5, a stepping motor 511, a gear train 11, an hour hand 12, a minute hand 13, a second hand 14, a calendar display section 15, It includes a watch case 17 and a watch movement 18 (hereinafter referred to as movement 18). In this embodiment, when one of the hour hand 12, minute hand 13, second hand 14, and calendar display section 15 is not specified, it is referred to as the hand 16.

Note that the oscillation circuit 3, frequency dividing circuit 4, timepiece control section 5, stepping motor 511, and wheel train 11 are components of the movement 18.
Generally, the mechanical body of a timepiece constituted by devices such as a time reference of the timepiece 1 is referred to as a movement. Electronic movements are sometimes called modules. In the completed state of the watch, the movement has, for example, a dial and hands attached to it, and these are housed in a watch case.

The battery 2 is, for example, a lithium battery, a so-called button battery. Note that the battery 2 may be a solar cell or a storage battery that stores power generated by the solar cell. The battery 2 supplies power to the timepiece control section 5 . Hereinafter, the battery 2 will also be referred to as a power source.

The oscillation circuit 3 is a passive element used to oscillate a predetermined frequency from its mechanical resonance by utilizing, for example, the piezoelectric phenomenon of a crystal. Here, the predetermined frequency is, for example, 32 [kHz].
The frequency dividing circuit 4 divides the signal of a predetermined frequency outputted by the oscillation circuit 3 into a desired frequency, and outputs the frequency-divided signal to the timepiece control section 5.
Note that the oscillation circuit 3 and the frequency dividing circuit 4 may both be included in the clock control section 5.

The clock control unit 5 measures time using the frequency-divided signal output from the frequency dividing circuit 4, and generates drive pulses based on the measured result. Note that, when moving the hands 16 in the forward rotation direction, the timepiece control unit 5 generates a drive pulse for forward rotation. When the timepiece control unit 5 moves the hands 16 in the reverse direction, it generates a drive pulse for reverse rotation. The timepiece control unit 5 outputs the generated drive pulse to the stepping motor 511.

The stepping motor 511 moves the hands 16 (the hour hand 12, the minute hand 13, the second hand 14, and the calendar display section 15) in accordance with the drive pulses output by the timepiece control section 5. In the example shown in FIG. 1, for example, one stepping motor 511 is provided for each of the hour hand 12, minute hand 13, second hand 14, and calendar display section 15.

The hour hand 12 rotates once every 12 hours as the timepiece control unit 5 drives the stepping motor 511. The minute hand 13 rotates once every 60 minutes as the timepiece control section 5 drives the stepping motor 511. The second hand 14 rotates once every 60 seconds as the timepiece control unit 5 drives the stepping motor 511. The calendar display section 15 is, for example, a pointer that displays the date, and the clock control section 5 drives the stepping motor 511 to advance the date by one day in 24 hours.

The clock control section 5 includes a sound alarm section 6 and a motor control section 53.
The sound alarm unit 6 includes a piezoelectric buzzer and makes a sound. In this embodiment, the alarm sound includes a pitch sound that is emitted at a predetermined frequency and a continuous sound that is emitted continuously for a predetermined period of time. The sound alarm unit 6 produces either a pitch sound or a continuous sound. Hereinafter, the sound alarm unit 6 will also be referred to as a sound alarm device.
The motor control unit 53 controls the stepping motor 511.

Note that the clock control section 5 may include an ambient temperature measurement section 54, an integrated operating time measurement section 55, and a sound alarm frequency measurement section 56.
The ambient temperature measuring section 54 measures the ambient temperature of the watch 1. For example, the ambient temperature measuring section 54 measures the ambient temperature of the watch 1 using a thermistor or the like. The ambient temperature measurement section 54 provides the alarm section 6 with information indicating the measured ambient temperature of the watch 1.
The cumulative operating time measuring unit 55 measures and stores the operating time of the sound alarm unit 6. The cumulative operating time measuring section 55 provides the power supply control section 51 with information indicating the stored cumulative operating time of the sound alarm section 6 .
The sound alarm number measurement section 56 measures and stores the number of times the sound alarm section 6 has been alarmed. The sound alarm frequency measuring section 56 provides the power supply control section 51 with information indicating the stored sound alarm frequency of the sound alarm section 6 .

[Functional configuration of alarm section 6]
Next, an example of the functional configuration of the power supply control section 51 according to the present embodiment will be described.
FIG. 2 is a diagram showing an example of the functional configuration of the sound alarm section 6 according to the present embodiment. The sound alarm section 6 is connected to the battery 2 and is driven by the power provided from the battery 2.
The sound alarm section 6 includes a piezoelectric buzzer 63, a coil 64, a capacitor 65, a switch 66, a sound signal generation section 61, and a current control section 62.

The piezoelectric buzzer 63 includes a first terminal 631 and a second terminal 632. The second terminal 632 is connected to the positive electrode of the power source (battery 2). The piezoelectric buzzer 63 is constructed by bonding together a piezoelectric ceramic thin plate (piezoelectric element) polarized in the thickness direction and a thin metal (or resin) diaphragm. In the case of a wristwatch, the piezoelectric buzzer 63 is attached to, for example, a metal back cover. In this case, the second terminal 632 of the piezoelectric buzzer 63 is electrically connected to the back cover side, and the positive electrode of the power source and the back cover are electrically connected to each other through a metal member that constitutes the movement of the timepiece.

The coil 64 has one end connected to a first terminal 631 of the piezoelectric buzzer 63 and the other end connected to a second terminal 632 of the piezoelectric buzzer 63. That is, the coil 64 is connected in parallel with the piezoelectric buzzer 63. In the case of a wristwatch, for example, the first terminal 631 of the piezoelectric buzzer 63 is electrically connected to the buzzer signal wiring of the circuit board constituting the movement by a spring spring made of a metal wire processed into a spiral shape. The coil 64 is mounted on the circuit board and connected to the buzzer signal wiring.

The capacitor 65 includes a positive terminal 652 and a negative terminal 651. The positive terminal 652 is connected to the second terminal 632 of the piezoelectric buzzer 63.
The capacitor 65 is a large capacity capacitor that charges the power supplied from the power source (battery 2). For example, capacitor 65 is a tantalum capacitor. For example, the capacitance of capacitor 65 is 150 uF.

The switch 66 is connected between the piezoelectric buzzer 63 and the capacitor 65 and switches the connection state between the first terminal 631 of the piezoelectric buzzer 63 and the negative terminal 651 of the capacitor 65. In this example, the connected state refers to a current conduction state. That is, the switch 66 switches the connection state between the first terminal 631 of the piezoelectric buzzer 63 and the negative terminal 651 of the capacitor 65 to at least one of a conductive state where current flows and a non-conductive state where no current flows.

The alarm signal generation unit 61 controls the connection state of the switch 66 into a conductive state and a non-conductive state at a predetermined frequency. The alarm signal generation unit 61 supplies power from at least one of the battery 2 and the capacitor 65 to the piezoelectric buzzer 63 by controlling the connection state of the switch 66 to a conductive state.
The alarm signal generating section 61 controls the connection state of the switch 66 to repeat the conductive state and non-conducting state at an audible frequency, and the piezoelectric buzzer 63 is supplied with power, so that the alarm section 6 generates the alarm sound. conduct.

The current control unit 62 includes an input terminal 625 connected to the negative terminal 651 of the capacitor 65, and an output terminal 626 connected to the negative terminal of the power source. In this example, the current control section 62 has a predetermined resistance component.

[First embodiment]
Next, a first embodiment will be described.
FIG. 3 is a diagram showing an example of the functional configuration of the sound alarm section 6 in the first embodiment. The sound alarm section 6A is an example of the sound alarm section 6 in the first embodiment. The same components as the sound alarm section 6 described in [Functional configuration of the sound alarm section 6] are given the same reference numerals, and the explanation thereof will be omitted.

The alarm section 6 is connected to the battery 2. The battery 2 is expressed as an equivalent circuit by an ideal voltage source 22 and an internal resistor 21 connected in series.
Internal resistance 21 is a resistance component that battery 2 has. In order to suppress a voltage drop in the sound alarm unit 6 when power is supplied from the battery 2, it is preferable that the internal resistance 21 is small. On the other hand, the internal resistance 21 increases depending on the usage period and usage conditions of the battery 2. For example, after 4 to 7 years, the internal resistance of a battery at -5°C to -10°C can reach about 1 kΩ.

The voltage of ideal voltage source 22 is determined by the combination of battery materials. The battery 2 used in this embodiment is a lithium manganese dioxide battery (CR battery), and the voltage of the ideal voltage source 22 is 3V. The voltage of the ideal voltage source 22 decreases depending on the usage period and usage conditions of the battery 2.

Note that the battery 2 may include a capacitor 23 near the battery 2. The capacitor 23 is provided to suppress fluctuations in the voltage supplied to the sound alarm section 6. The capacitor 23 is a bypass capacitor for removing noise from the sound reporting section 6. The capacitance of the capacitor 23 is, for example, about 1 uF to 10 uF. In the power supply control unit 51 , the battery 2 may include a plurality of capacitors 23 near the battery 2 .

In this embodiment, the sound alarm section 6A includes a piezoelectric buzzer 63, a coil 64, a capacitor 65, a switch 66, a sound signal generation section 61, a resistor 67, and a current control section 62A.
Specifically, the alarm signal generation section 61 may be included in a microcomputer (not shown). The microcomputer (not shown) may include memories such as RAM (Random access memory) and ROM (Read only memory).
The alarm signal generation unit 61 controls the connection state of the switch 66 into a conductive state and a non-conductive state at a predetermined frequency according to a program stored in the RAM or ROM. Specifically, the alarm signal generation unit 61 outputs a pulse signal at a predetermined frequency for a predetermined period from an output port of a general-purpose output port provided in a microcomputer (not shown). The sound alarm section 6A performs the sound during a predetermined period during which the pulse signal is output.

Note that the alarm signal generation section 61 only needs to be able to output a pulse signal at a predetermined frequency for a predetermined period, and may be configured by a transmitting circuit or the like.

The switch 66 includes a resistor 662 and a transistor 661. The transistor 661 is also referred to as a switch or a first switch.
In this example, transistor 661 is an NPN transistor. When the alarm signal generation section 61 outputs a high level, a base current limited by the resistor 662 causes a collector current to flow between the collector and emitter of the transistor 661. When the alarm signal generation section 61 outputs a low level, the collector current does not flow, so the switch 66 is controlled to be in a disconnected state.
In this example, the resistance value of resistor 662 is 10 kΩ.

The resistor 67 is provided to optimize the current flowing through the coil 64 when the switch 66 is switched to the connected state. For example, the resistance value of the resistor 67 is 33Ω.
Note that the resistor 67 may be constituted by a diode or the like, and may not be provided if the current flowing through the coil 64 is not optimized.

The current control section 62A is an example of the current control section 62. The current control unit 62A controls the current when power is supplied from the battery 2 to the capacitor 65.
When the switch 66 is in a non-conducting state, the capacitor 65 is being charged by the battery 2. When the switch 66 is controlled to be conductive, the power charged in the capacitor 65 is discharged to the piezoelectric buzzer 63 and the coil 64.
When the switch 66 is controlled to be non-conductive again, the battery 2 charges the capacitor 65. The current when the capacitor 65 is charged is controlled by the current control section 62A.

Here, the voltage of the battery 2 drops due to the rush current when power is supplied from the battery 2 to the capacitor 65. Specifically, when current flows from the battery 2 to the capacitor 65 by controlling the switch 66 to be in a non-conductive state, the battery voltage is equal to the voltage of the ideal voltage source 22 of the battery 2 compared to the internal resistance 21 of the battery 2. The voltage drops to the voltage divided by the resistance component of the current control section 62A.
In this example, the resistance value of the resistance component of the current control unit 62 is greater than the resistance value of the internal resistance 21 of the power source (battery 2). For example, the resistance value of the current control section 62A is 10 kΩ.

[Second embodiment]
Next, a second embodiment will be described.
FIG. 4 is a diagram showing an example of the functional configuration of the sound alarm section 6 in the second embodiment. The sound alarm section 6B is an example of the sound alarm section 6 in the second embodiment. The same components as the sound alarm section 6A described in the first embodiment are given the same reference numerals, and the description thereof will be omitted.
The sound alarm section 6B includes a current control section 62B. The current control section 62B is an example of the current control section 62.

The current control section 62B includes a resistor 621, a transistor 622, and an alarm power supply control section 623. The transistor 622 is also referred to as a second switch.
The transistor 622 switches the connection state between the input terminal 625 and the output terminal 626. In this example, the connected state refers to a current conduction state. In other words, the transistor 622 (second switch) switches the connection state between the input terminal 625 and the output terminal 626 to at least one of a conductive state where current flows and a non-conductive state where no current flows.

In this example, the transistor 622 is an N-channel MOS FET (Metal-Oxide-Semiconductor Field-Effect Transistor).
Note that the transistor 622 may be a general-purpose output port included in a microcomputer (not shown).

The alarm power supply control unit 623 charges the capacitor 65 with the power of the power supply (battery 2) by controlling the connection state of the transistor 622 (second switch) to a conductive state. Further, the alarm power supply control unit 623 controls the connection state of the battery 2 and the capacitor 65 to a non-conduction state by controlling the connection state of the transistor 622 (second switch) to a non-conduction state. That is, while the alarm power supply control section 623 is controlling the non-conducting state, it is possible to suppress leakage current from flowing from the capacitor 65.

Specifically, during a period in which the alarm signal generation section 61 outputs a pulse signal at a predetermined frequency for a predetermined period to generate an alarm, the alarm power supply control section 623 controls the transistor 622 to be in a conductive state. . Furthermore, during a period in which the alarm signal generation section 61 does not output a pulse signal (that is, a period in which the alarm signal is not output), the alarm power supply control section 623 controls the transistor 622 to be non-conductive.

[Third embodiment]
Next, a third embodiment will be described.
FIG. 5 is a diagram showing an example of the functional configuration of the sound alarm section 6 in the third embodiment. The sound alarm section 6C is an example of the sound alarm section 6 in the third embodiment. The same components as the sound alarm section 6B described in the second embodiment are given the same reference numerals, and the description thereof will be omitted.
The sound alarm section 6C includes a current control section 62C. The current control section 62C is an example of the current control section 62.

The current control unit 62C further includes a resistor 627 and a transistor 628. The transistor 628 is also referred to as a third switch.
Transistor 628 switches the connection state between input terminal 625 and output terminal 626. In this example, the connected state refers to a current conduction state. Further, the transistor 628 (third switch) is a different switch from the transistor 622 (second switch). In other words, the transistor 628 (third switch) switches the connection state between the input terminal 625 and the output terminal 626 to at least one of a conductive state through which current flows and a non-conductive state where no current flows; This switch is different from the second switch).

In this example, transistor 628 is an N-channel MOS type FET.
Note that the transistor 628 may be a general-purpose output port included in a microcomputer (not shown).

The alarm power supply control unit 623 controls the transistor 628 (third switch) to be conductive, thereby charging the capacitor 65 with the power of the power supply (battery 2). Further, the alarm power supply control unit 623 controls the connection state of the battery 2 and the capacitor 65 to a non-conduction state by controlling the connection state of the transistor 628 (third switch) to a non-conduction state.

In this example, the resistance value of resistor 627 is less than the resistance value of resistor 621. In other words, the alarm power supply control unit 623 charges the capacitor 65 via the resistor 627 by controlling the transistor 628 to conduct, compared to the case where the capacitor 65 is charged via the resistor 621 by controlling the transistor 622 to conduct. The capacitor 65 can be charged in a shorter time if the capacitor 65 is charged in a shorter time.
The alarm power supply control unit 623 controls the transistor 628 to be conductive to charge the capacitor 65 with power in a short time, and controls the transistor 628 to be non-conductive when the capacitor 65 has finished charging. At the same time, the transistor 622 (second switch) is controlled to be conductive.

Note that the alarm power supply control unit 623 predicts the resistance value of the internal resistance 21 of the battery 2 from the values measured by the ambient temperature measurement unit 54, the cumulative operating time measurement unit 55, or the alarm frequency measurement unit 56. good. In this case, the alarm power supply control section 623 is based on the resistance value of the internal resistance 21 of the battery 2 predicted from the values measured by the ambient temperature measurement section 54, the cumulative operating time measurement section 55, or the alarm frequency measurement section 56, respectively. Then, the time for controlling the transistor 628 to conduct is calculated. The alarm power supply control unit 623 controls the transistor 628 to be in a conductive state based on the calculated time. With this configuration, the time required for charging can be varied in accordance with changes in the resistance value of the internal resistance 21 of the battery 2.

[About pitch sounds and continuous sounds]
Here, pitch sounds and continuous sounds in this embodiment will be explained.
FIG. 6 is a diagram for explaining pitch sounds and continuous sounds in this embodiment.
In the figure, the horizontal axis shows time, and the vertical axis shows the control signal of the switch 66 output by the alarm signal generation section 61. When the control signal for the switch 66 is at a high level, the switch 66 is controlled to be in a conductive state, and when the control signal for the switch 66 is at a low level, the switch 66 is controlled to be in a non-conductive state.
FIG. 6(A) shows an example of a pitch sound, and FIG. 6(B) shows an example of a continuous sound.

FIG. 6(A) is an example of a control signal for the switch 66 output by the alarm signal generation section 61 when the alarm section 6 issues a pitch tone.
The time period during which the control signal is at a high level is t _on1 , and the period from when the control signal becomes high level until it becomes high level again is period T ₁ . The alarm signal generation unit 61 controls the connection state of the switch 66 at a frequency f ₁ =1/T ₁ during a period t _on2 . The alarm signal generation unit 61 controls the connection state of the switch 66 during a period t _on2 with a cycle T ₂ .
For example, the frequency _f1 is 2 kHz, the period t _on2 is 31.25 ms, and the period T2 is 333 ms (180 spm).

FIG. 6(B) is an example of a control signal for the switch 66 output by the alarm signal generation section 61 when the alarm section 6 issues a continuous sound (for example, a timer time-up sound).
The time period during which the control signal is at a high level is defined as _ton3 , and the period from when the control signal becomes high level until it becomes high level again is defined as period _T3 . The alarm signal generation unit 61 controls the connection state of the switch 66 at a frequency f ₃ =1/T ₃ during a period T ₄ .
The alarm signal generation unit 61 outputs a pulse signal at a predetermined frequency (frequency f ₃ =1/T ₃ ) for a predetermined period (period T ₄ ), so that the alarm unit 6 reports continuous sound. It makes a sound. For example, the frequency f ₁ is 4 kHz, and the period T ₄ is about 3 seconds to 6 seconds.

[Fourth embodiment]
Next, a fourth embodiment will be described.
FIG. 7 is a diagram showing an example of the functional configuration of the sound alarm section 6 in the fourth embodiment. The sound alarm section 6D is an example of the sound alarm section 6 in the fourth embodiment. The same components as the sound alarm section 6C described in the third embodiment are given the same reference numerals, and the description thereof will be omitted.

The sound alarm section 6D further includes a continuous sound control section 68.
The continuous sound control section 68 includes a second input terminal 685 connected to the negative terminal 651 of the capacitor 65, and a second output terminal 686 connected to the negative terminal of the power source (battery 2). The continuous sound control unit 68 switches the connection state between the second input terminal 685 and the second output terminal 686 to at least one of a conductive state where current flows and a non-conductive state where no current flows.
Specifically, the continuous sound control section 68 includes a second alarm power supply control section 681 and a transistor 682. The transistor 682 is also referred to as a fourth switch.

The transistor 682 switches the connection state between the second input terminal 685 and the second output terminal 686. In this example, transistor 682 is an N-channel MOS FET.
Note that the transistor 682 may be a general-purpose output port included in a microcomputer (not shown).
The second alarm power supply control unit 681 connects the negative terminal 651 of the capacitor 65 to the negative electrode of the battery 2 by controlling the connection state of the transistor 682 (fourth switch) to the conductive state. For example, the on-resistance of the transistor 682 is about several ohms to several tens of ohms.

Here, if the sound alarm section 6 issues a sound while the current is being controlled by the current control section 62 having a resistance component, the sound volume (sound pressure) may decrease. In this example, after the capacitor 65 is charged by the current control section 62, the continuous sound control section 68 connects the negative terminal 651 of the capacitor 65 to the negative terminal of the battery 2, thereby increasing the alarm volume (sound pressure). Prevent the decline.
In other words, the continuous sound control section 68 connects the second input terminal 685 when the alarm signal generation section 61 controls the switch 66 at a predetermined frequency for a predetermined period or more (that is, during the period in which continuous sound is being reported). The connection state with the second output terminal 686 is controlled to be in a conductive state.

[About the control of each switch during pitch tone alert]
Here, control of each switch (first switch, second switch, third switch, and fourth switch) in this embodiment will be explained.
FIG. 8 is a diagram for explaining the state of each switch, the potential of the capacitor 65, and the driving state of the stepping motor 511 at the time of the pitch tone alarm according to the present embodiment.
8(A) shows the state of the second switch, FIG. 8(B) shows the state of the third switch, FIG. 8(C) shows the state of the fourth switch, and FIG. 8(D) shows the state of the capacitor. 8(E) shows the state of the first switch, FIG. 8(F) shows the driving state of the stepping motor 511, and the horizontal axis represents time.
In the figure, the connection state of each switch is shown such that a low level is a disconnected state and a high level is a connected state.

Before time _t11 , each switch is in a disconnected state. In this state, the positive terminal 652 of the capacitor 65 is connected to the positive electrode of the battery 2. The negative terminal 651 of the capacitor 65 is not connected to the negative electrode of the battery 2 . Therefore, the potential Vc of the negative terminal 651 of the capacitor 65 is the same potential as the potential Vdd of the battery 2 (the positive electrode of the power supply).

The alarm power supply control unit 623 controls the third switch to be in a conductive state at time _t11 . The alarm power supply control unit 623 charges the capacitor 65 with the power of the battery 2 by controlling the third switch to be in a conductive state. At time _t11 , when the third switch is controlled to be conductive, the potential Vc of the negative terminal 651 of the capacitor 65 drops to the potential Vss of the negative terminal 651 of the battery 2. In other words, the capacitor 65 is charged.

Here, the capacitor 65 is charged via the second resistor by controlling the second switch to a conductive state, and the capacitor 65 is controlled via the third resistor by controlling the third switch to a conductive state. The time it takes for the capacitor 65 to charge and the value of the voltage drop of the battery 2 at that time differ depending on the case.
Since the resistance value of the third resistor is smaller than the resistance value of the second resistor, the third resistor In the case where the capacitor 65 is controlled via the third resistor by controlling the capacitor 65 to be conductive, charging can be performed in a shorter time and the voltage drop is also larger.

When the stepping motor 511 is being driven, charging via the third switch and the third resistor, which can be charged in a short time and has a large voltage drop, will cause the stepping motor 511 and other electronic components included in the watch 1 to be charged. The operating voltage may fall below the lower limit of the operating voltage.
During the period from time _t11 to time _t12 , stepping motor 511 is not driven. Therefore, during the period from time _t11 to time _t12 , the capacitor 65 is charged via the second resistor by controlling the second switch to be conductive.

At time _t12 , when the capacitor 65 is charged with power, the alarm power supply control unit 623 controls the second switch to be in the connected state and controls the third switch to be in the non-conductive state.
Note that the determination as to whether or not the capacitor 65 is charged may be determined in advance at a predetermined time based on the capacitance of the capacitor 65 and the resistance value of the current control section 62, or may be configured to obtain a voltage value.

From time _t12 to time _t19 , the timepiece control unit 5 drives the stepping motor 511.
From time _t13 to time _t18 , the sound alarm section 6 makes a sound alarm. In the example shown in the figure, the alarm section 6 makes an alarm using a pitch tone. From time _t13 to time _t14 , the alarm signal generation unit 61 controls the first switch at a predetermined frequency. In this case, the power charged in the capacitor 65 is consumed by the piezoelectric buzzer 63 and the coil 64, and the potential Vc of the negative terminal 651 of the capacitor 65 increases (that is, the potential difference across the capacitor becomes smaller).
At time _t14 , the alarm signal generation unit 61 controls the first switch to be disconnected. When the first switch is controlled to be disconnected, the capacitor 65 is charged via the second switch and the second resistor. At this time, the time it takes for the capacitor 65 to be charged is longer than when the capacitor 65 is charged via the third switch and the third resistor.

When the period from time t ₁₃ to time t ₁₅ is defined as period T, the alarm signal generation unit 61 issues a pitch sound at period T. The alarm signal generation unit 61 ends the pitch tone alarm at time _t18 , and controls the third switch to be in a disconnected state.
At time _t19 , the timepiece control unit 5 ends driving the stepping motor 511. After time _t19 , each switch is controlled to be disconnected, so the capacitor 65 remains charged, as shown by waveform W12. However, due to leakage current, capacitor 65 is discharged as shown in waveform W11.

[About the control of each switch during continuous tone]
FIG. 9 is a diagram for explaining the states of each switch and the potential of the capacitor 65 during continuous tone alerting according to the present embodiment.
9(A) shows the state of the second switch, FIG. 9(B) shows the state of the third switch, FIG. 9(C) shows the state of the fourth switch, and FIG. 9(D) shows the state of the capacitor. 9E shows the potential Vc of the negative terminal 651 of 65, the state of the first switch is shown in FIG. 9E, and the horizontal axis shows time.
In the figure, the connection state of each switch is shown such that a low level is a disconnected state and a high level is a connected state.

Before time _t21 , each switch is in a disconnected state. In this state, the positive terminal 652 of the capacitor 65 is connected to the positive electrode of the battery 2. The negative terminal 651 of the capacitor 65 is not connected to the negative electrode of the battery 2 . Therefore, the potential Vc of the negative terminal 651 of the capacitor 65 is the same potential as the potential Vdd of the battery 2.

The alarm power supply control unit 623 controls the third switch to be in a conductive state at time _t21 . The alarm power supply control unit 623 charges the capacitor 65 with the power of the battery 2 by controlling the third switch to be in a conductive state. At time _t21 , when the third switch is controlled to be conductive, the potential Vc of the negative terminal 651 of the capacitor 65 drops to the potential Vss of the negative terminal 651 of the battery 2. In other words, the capacitor 65 is charged.
At time _t22 , when the capacitor 65 is charged with power, the alarm power supply control section 623 controls the third switch to be non-conductive.

The second alarm power supply control unit 681 controls the fourth switch to be in a conductive state at time _t23 . The second alarm power source control section 681 connects the negative terminal 651 of the capacitor 65 to the negative electrode of the battery 2 by controlling the fourth switch to be in a conductive state.

From time t ₂₄ to time t ₂₅ , the alarm signal generation unit 61 issues a continuous tone. In this example, the negative terminal 651 of the capacitor 65 is connected to the negative terminal of the battery 2 without a resistance component, so the alarm volume (sound pressure) does not decrease.

At time _t25 , the alert signal generation unit 61 ends the continuous tone alert. When the alarm signal generation section 61 finishes generating the continuous tone, the second alarm power supply control section 681 controls the fourth switch to be in a non-conducting state.
After time _t26 , each switch is controlled to be disconnected, so the capacitor 65 remains charged, as shown by waveform W22. However, due to leakage current, capacitor 65 is discharged as shown in waveform W21.

[Voltage drop in power supply voltage]
FIG. 10 is a diagram for explaining the voltage drop in the power supply voltage according to this embodiment. The voltage drop in the power supply voltage (potential Vdd of the battery 2) will be explained with reference to the same figure.
FIG. 10(A) shows the driving state of the stepping motor 511, FIG. 10(B) shows the state of the first switch, and the horizontal axis represents time. FIG. 10C shows the potential Vdd of the battery 2, with the vertical axis representing voltage and the horizontal axis representing time.
In the figure, the connection state of the first switch is shown such that a low level is a disconnected state and a high level is a connected state.

Before time _t31 , the stepping motor 511 is in a stopped state and the first switch is in a disconnected state. In this state, the potential Vdd of the battery 2 is _v1 .
At time _t31 , the timepiece control unit 5 starts driving the stepping motor 511. When the stepping motor 511 is driven, the potential Vdd of the battery 2 drops to _v2 .
At time _t32 , the alarm signal generation unit 61 starts the alarm signal by controlling the first switch. In this example, the alarm signal generation unit 61 issues a pitch tone from time t ₃₂ to time t ₃₃ .

From time _t32 to time _t33 , the driving of the stepping motor 511 and the sound alarm are performed at the same time, but the potential Vdd of the battery 2 never drops below _v2 when the stepping motor 511 is driven.

[Summary of embodiments]
According to the embodiment described above, the sound alarm unit 6 includes the capacitor 65 and supplies the electric power charged in the capacitor 65 to the piezoelectric buzzer 63 and the coil 64. Furthermore, by including the current control unit 62, the sound alarm unit 6 can control the current that flows when charging the capacitor 65. The current control unit 62 can prevent the rush current that flows when charging the capacitor 65 by controlling the current that flows when charging the capacitor 65. Therefore, the sound alarm section 6 can prevent the voltage drop of the battery 2.

Here, according to the prior art, when a tone is sounded, a voltage drop occurs in accordance with the internal resistance value of the battery.
FIG. 11 is a diagram showing an example of the functional configuration of a sound alarm circuit 99 in a conventional example. The functional configuration of the conventional sound alarm circuit 99 will be described with reference to the same figure.
The sound alarm circuit 99 includes a power source 90 , a coil 94 , a piezoelectric buzzer 95 , a switch 96 , a resistor 97 , a resistor 98 , and a signal generation circuit 93 . When the alarm circuit 99 issues an alarm, the signal generation circuit 93 outputs a pulse signal. Switch 96 causes current to flow through coil 94 and piezoelectric buzzer 95 in accordance with the pulse signal output from switch 93 .

According to the conventional sound alarm circuit 99, when the switch 96 is switched to the connected state, the potential on the positive side of the power source 90 is equal to the output potential of the ideal power source 92, and the internal resistance 91 and the resistor 97 of the power source 90. The voltage drops to the voltage divided by the voltage.

FIG. 12 is a diagram for explaining the voltage drop in the power supply voltage in the conventional example. Referring to the figure, a voltage drop in the power supply voltage in the conventional technology will be explained.
FIG. 12(A) shows the driving state of a motor (not shown), FIG. 12(B) shows the state of the switch 96, and the horizontal axis represents time. FIG. 12C shows the potential of the power supply 90, with the vertical axis representing voltage and the horizontal axis representing time.
In the figure, the connection state of the first switch is shown such that a low level is a disconnected state and a high level is a connected state.

Before time _t91 , the motor (not shown) is in a stopped state and the switch 96 is in a disconnected state. In this state, the potential of power supply 90 is _v91 .
At time _t91 , when a motor (not shown) is driven, the potential of power supply 90 drops to _v92 . Further, at time _t92 , when the switch 96 is controlled to be connected, the potential of the power supply 90 drops to _v93 . In this way, in the conventional technology, a voltage drop occurs in the power supply voltage.

Further, according to the embodiment described above, the resistance value of the resistance component of the current control unit 62 included in the sound alarm unit 6 is greater than the resistance value of the internal resistance 21 of the battery 2. The voltage drop due to the rush current is limited by the values of the internal resistance 21 of the battery 2 and the resistance component of the current control section 62. Since the resistance value of the resistance component of the current control unit 62 according to this embodiment is larger than the resistance value of the internal resistance 21 of the battery 2, the sound alarm unit 6 can suppress voltage drop caused by rush current.

Further, according to the embodiment described above, the current control section 62 included in the sound alarm section 6 includes a transistor 622 and a sound alarm power supply control section 623. The alarm power supply control unit 623 can suppress leakage current from the capacitor 65 by controlling the transistor 622 to be disconnected. Therefore, the sound alarm section 6 can reduce power consumption except during the sound alarm operation.

Further, according to the embodiment described above, the current control section 62 further includes a resistor 627 and a transistor 628. The resistance value of the resistor 627 is smaller than the resistance value of the resistor 621. The alarm power supply control unit 623 rapidly charges the capacitor 65 by controlling the transistor 628 to the connected state, and controls the transistor 622 to the connected state while the capacitor 65 is charged. Therefore, by further including the resistor 627 and the transistor 628, the current control unit 62 can shorten the charging time of the capacitor 65.

Furthermore, in the conventional technology, lower power consumption was sometimes achieved by adding a resistor. If the current flowing through the piezoelectric buzzer is limited by a resistor, the sound volume (sound pressure) may decrease.
According to the embodiment described above, the sound alarm section 6 includes the continuous sound control section 68. When the sound alarm section 6 issues a sound, the continuous sound control section 68 connects the negative terminal 651 of the capacitor 65 to the negative terminal of the battery 2, so that the continuous sound control section 68 can control the current flow in the coil without going through the current control section 62 having a resistance component. 64 and the piezoelectric buzzer 63.
Therefore, the sound alarm unit 6 can perform the sound alarm operation without reducing the sound volume (sound pressure).

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to the above-described embodiments, and design changes may be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1... Clock, 2... Battery, 3... Oscillator circuit, 4... Frequency dividing circuit, 5... Clock control section, 6... Alarm section, 511... Stepping motor, 11... Gear train, 12... Hour hand, 13... Minute hand, 14 ... second hand, 15 ... calendar display section, 17 ... watch case, 18 ... watch movement, 21 ... internal resistance, 22 ... ideal voltage source, 53 ... motor control section, 54 ... ambient temperature measurement section, 55 ... cumulative operating time measurement Section, 56... Sound alarm frequency measuring section, 61... Sound alarm generation section, 62... Current control section, 63... Piezoelectric buzzer, 64... Coil, 65... Capacitor, 66... Switch, 67... Resistor, 68... Continuous sound control 621...Resistor, 6211...Resistor, 6212...Resistor, 622...Transistor, 6221...Transistor, 6222...Transistor, 623...Alarm power supply control section, 661...Transistor, 662...Resistor, 681...Second alarm power supply control Part, 682...Transistor

Claims (7)

a piezoelectric buzzer comprising a first terminal and a second terminal connected to a positive electrode of a power source;
a coil having one end connected to the first terminal of the piezoelectric buzzer and the other end connected to the second terminal of the piezoelectric buzzer;
a capacitor comprising a negative terminal and a positive terminal connected to the second terminal of the piezoelectric buzzer, and charging with power supplied from the power source;
a switch that switches at least a connection state between the first terminal of the piezoelectric buzzer and the negative terminal of the capacitor to either a conductive state where current flows or a non-conductive state where current does not flow;
an alarm signal generation unit that controls the connection state of the switch to a conductive state and a non-conductive state at a predetermined frequency;
a current control unit including an input terminal connected to the negative terminal of the capacitor, and an output terminal connected to the negative terminal of the power source, and having a predetermined resistance component ;
The current control section includes:
a second switch different from the switch that switches the connection state between the input terminal and the output terminal to at least one of a conductive state through which a current flows and a non-conductive state where no current flows;
The device further includes an alarm power source control unit that charges the capacitor with power from the power source by controlling the connection state of the second switch to a conductive state.
Alarm device. The current control section includes:
further comprising a third switch different from the second switch that switches the connection state between the input terminal and the output terminal to at least one of a conductive state through which current flows and a non-conductive state where current does not flow;
The alarm power supply control unit controls the third switch to be in a conductive state to charge the power from the power source to the capacitor, and to make the second switch to be in a conductive state while the capacitor is being charged with power. The sound alarm device according to claim 1 . a piezoelectric buzzer comprising a first terminal and a second terminal connected to a positive electrode of a power source;
a coil having one end connected to the first terminal of the piezoelectric buzzer and the other end connected to the second terminal of the piezoelectric buzzer;
a capacitor comprising a negative terminal and a positive terminal connected to the second terminal of the piezoelectric buzzer, and charging with power supplied from the power source;
a switch that switches at least a connection state between the first terminal of the piezoelectric buzzer and the negative terminal of the capacitor to either a conductive state where current flows or a non-conductive state where current does not flow;
an alarm signal generation unit that controls the connection state of the switch to a conductive state and a non-conductive state at a predetermined frequency;
a current control unit including an input terminal connected to the negative terminal of the capacitor and an output terminal connected to the negative terminal of the power source, and having a predetermined resistance component;
Equipped with
a second input terminal connected to the negative terminal of the capacitor; and a second output terminal connected to the negative terminal of the power source, and a connection state between the second input terminal and the second output terminal; Further comprising a continuous sound control unit that switches at least one of a conductive state where current flows and a non-conductive state where current does not flow,
The continuous sound control unit controls the connection state between the second input terminal and the second output terminal to be in a conductive state when the alarm signal generation unit controls the switch at a predetermined frequency for a predetermined time or more.
Alarm device . The sound alarm device according to any one of claims 1 to 3 , wherein a resistance value of a resistance component of the current control section is larger than an internal resistance value of the power source. The sound alarm device according to any one of claims 1 to 4 , wherein the capacitor is a tantalum capacitor. A movement comprising the sound alarm device according to any one of claims 1 to 5 . A timepiece comprising the movement according to claim 6 .

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