JP3628080B2 - Electronic clock - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an electronic timepiece having a reverse rotation function of a step motor.
[0002]
[Prior art]
A normal electronic timepiece step motor is configured such that the rotor rotates only in the forward direction and does not rotate in the reverse direction in response to an input signal. Therefore, when it is desired to reversely rotate the rotor for changing the pointer position, etc., it is necessary to drive the rotor with a special reverse rotation pulse. Regarding this special reverse rotation pulse, Japanese Patent Application Laid-Open No. 52-80063 discloses examples of a reverse rotation pulse having two alternating pulses as one set and a reverse rotation pulse having three alternating pulses as one set. It is disclosed.
[0003]
On the other hand, recently, a solar cell (solar cell) is provided, and light energy incident on the solar cell is converted into electrical energy and stored in a capacitor or secondary battery. The capacitor or secondary battery is used as a power source. Many watches, so-called solar cell watches, have appeared.
[0004]
This solar cell clock mainly stores electric energy during the day and releases electric energy at night, and the voltage of the capacitor and the secondary battery changes considerably even during the day. Accordingly, it is desired that the step motor operates normally with a voltage as low as possible particularly in such a solar cell timepiece.
[0005]
[Problems to be solved by the invention]
However, the reverse rotation operation of the step motor described above has a narrower operating voltage range than normal operation, and it is difficult to operate normally at a low voltage. In addition, since the fast-forward drive of the forward rotation also has a high drive frequency, it is necessary to narrow the pulse width, and it is difficult to operate normally at a low voltage. An object of the present invention is to provide an electronic timepiece that prohibits reverse rotation of a step motor at a voltage lower than a predetermined voltage when operating an external operation member, and forward-rotates the step motor with a wide pulse having a low drive frequency. Is to provide.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the configuration of the present invention includes a hand movement pulse generating circuit for generating a normal hand movement pulse, a fast feed pulse generating circuit for generating a forward rotation fast feed pulse, and a reverse rotation pulse for generating a reverse rotation pulse. A voltage level determination circuit for determining a level of a power supply voltage in an electronic timepiece having a generation circuit and a step motor that performs normal rotation, fast forward forward rotation, and reverse rotation in response to these pulses; A control circuit that is controlled by the output signal of the level determination circuit and selectively passes the output signal of each pulse generation circuit, and when the power supply voltage is outside a predetermined voltage range and a voltage determination signal is generated from the voltage level determination circuit, The control circuit prohibits passage of the reverse rotation pulse.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the embodiment, a solar cell timepiece that moves the hands every second, the forward rotation fast-forward operation and the reverse rotation operation of the step motor will be described by taking the position correction of the time display hand as an example.
[0008]
FIG. 1 is a circuit block diagram of an electronic timepiece according to the present invention. In FIG. 1, reference numeral 1 is an oscillation circuit, and 2 is a frequency dividing circuit, which divides the frequency until a signal necessary for the operation of the timepiece is obtained based on the output of the oscillation circuit 1.
[0009]
Reference numeral 3 denotes a hand movement pulse generating circuit for generating pulses for normal hand movement. During normal hand movement, a hand movement pulse having a pulse width of 5 ms as shown in FIG. 2A is output every second. Reference numeral 4 denotes a low voltage hand movement pulse generation circuit which outputs two hand movement pulses having a pulse width of 6 ms as shown in FIG. 2B every 2 seconds. Although it is a general technique at present, the rotation and non-rotation of the rotor 22 is detected after driving by the hand movement pulse, and a correction drive pulse having a wide pulse width is output from the hand movement pulse generation circuit 3 when the non-rotation is detected. In this case, the low voltage hand movement pulse generation circuit 4 is not necessarily required. Reference numeral 5 denotes a fast-forward pulse generation circuit. When the external operation member 34 to be described later is continuously pressed, a fast-forward pulse having a pulse width of 4 ms as shown in FIG. 2C is output at a rate of 64 per second. The reason why the pulse width is made narrower than that of the normal pulse is to increase the drive frequency. However, since the pulse width is narrow, the step motor is difficult to operate normally at a low voltage. 6 is a low-voltage fast-forward pulse generation circuit. When the external operation member 34 or the external operation member 35, which will be described later, is continuously pressed, a fast-forward pulse with a pulse width of 6 ms as shown in FIG. To do. Compared with the output of the fast-forwarding pulse generation circuit 5, the driving frequency is half and the pulse width is wide. Therefore, the step motor can be operated normally even at a low voltage that cannot be driven by the output signal of the fast-forwarding pulse generation circuit 5. Reference numeral 7 denotes a reverse rotation pulse generation circuit. When an external operation member 35 to be described later is continuously pushed, three pulses as shown in FIG. 2 (e) are set as one set, and pulses are output at a rate of 32 sets per second.
[0010]
A solar cell 8 converts light energy into electrical energy and charges a capacitor or a secondary battery as a power source. Reference numeral 9 denotes a voltage level discrimination circuit, which outputs a HIGH signal (hereinafter referred to as H signal) when the power supply voltage is a predetermined voltage, for example, 1.2 V or higher, and a LOW signal (hereinafter referred to as L signal) when it is less than 1.2 V. Output). The voltage level discrimination circuit 9 forcibly passes a current when the power supply voltage becomes 1.8 V or higher. It is configured to prevent over 8V. A control circuit 10 includes AND gates 11, 12, 13, 14, 15 and an OR gate 16. The AND gate 11 is applied with the output signal of the hand movement pulse generation circuit 3, the AND gate 12 is supplied with the output signal of the low voltage hand movement pulse generation circuit 4, and the AND gate 13 is supplied with the fast-forward pulse. The output signal of the circuit 5 is applied to the AND gate 14 and the output signal of the low-voltage fast-forward pulse generating circuit 6 is applied to the AND gate 15, and the output signal of the reverse rotation pulse generating circuit 7 is applied to the AND gate 15. The AND gate 11, the AND gate 13, and the AND gate 15 are controlled by a direct output signal of the voltage level discriminating circuit 9. The AND gate 12 and the AND gate 14 are controlled by the voltage level discriminating circuit 9. The output signals of the AND gates 11, 12, 13, 14, and 15 are respectively applied to the OR gate 16 and the output signal of the OR gate 16 is toggled. The voltage is applied to the T terminal of the flip-flop 17 and the AND gates 18 and 19.
[0011]
A toggle flip-flop 17 inverts the Q and Qbar output signals at the rising edge of the OR gate 16 output signal, the Q output signal controls the AND gate 18, and the Qbar output signal is an AND gate. 19 is controlled. A drive circuit 20 is composed of two P-channel MOS transistors and two N-channel MOS transistors as is well known. A step motor coil 21 is connected to the output terminal of the drive circuit 20 . Reference numeral 22 denotes a step motor rotor, and the rotation of the rotor 22 is transmitted to the second hand 30, the minute hand 31, and the hour hand 32 shown in FIG. 3 via a time display train wheel (not shown).
[0012]
S1, S2, and S3 are switches, and are connected to the VSS of the power source during normal operation.
[0013]
In the above configuration, first, the power supply voltage is 1. The operation at the time of normal operation of 2V or more will be described.
[0014]
During normal hand movement, signals are output from the hand movement pulse generation circuit 3 and the low voltage hand movement pulse generation circuit 4, but since the power supply voltage is 1.2 V or higher, the AND gate 11 is in an ON state, and the AND gate 12 Is off. For this reason, a hand movement pulse which is an output signal from the hand movement pulse generating circuit 3 is applied to the toggle flip-flop 17, the AND gate 18 and the AND gate 19 through the OR gate 16. If the Q output of the toggle flip-flop 17 becomes the H signal at the first hand movement pulse, the AND gate 18 is turned on, and the hand movement pulse is applied to the drive circuit 20 via the AND gate 18. Therefore, a current flows through the coil 21, and the rotor 22 rotates in the positive direction by one step. At the next hand movement pulse, the Qbar output of the toggle flip-flop 17 becomes an H signal, so that the AND gate 19 is turned on, and the hand movement pulse is applied to the drive circuit 20 via the AND gate 19. Therefore, a current in the opposite direction flows through the coil 21, and the rotor 22 further rotates in the forward direction by one step. In this way, the step motor rotates in the positive direction step by step, and this rotation drives the second hand 30, the minute hand 31, and the hour hand 32 shown in FIG. 3 to display the time.
[0015]
Next, the operation of correcting the pointer position when the power supply voltage is 1.2 V or higher will be described. First, the case where the pointer position is corrected by forward rotation of the step motor will be described.
[0016]
First, when the crown 33 which is the first external operation member shown in FIG. 3 is pulled out to the first stage, the switch S1 shown in FIG. When reset, the output signals of the hand movement pulse generation circuit 3 and the low voltage hand movement pulse generation circuit 4 are not generated. Next, when the push button 34 which is the second external operation member shown in FIG. 3 is pushed, the switch S2 is connected to VDD, and the H signal is fast-forwarded for low voltage via the fast-forwarding pulse generation circuit 5 and the OR gate 24. Applied to the pulse generation circuit 6. When the button is kept pressed for 1 second or longer, output signals are continuously generated from the fast-forward pulse generating circuit 5 and the low-voltage fast-forward pulse generating circuit 6 and applied to the AND gate 13 and the AND gate 14, respectively. However, since the power supply voltage is 1.2 V or more, the AND gate 13 is in the on state and the AND gate 14 is in the off state, and the output signal of the fast-forward pulse generating circuit 5 is the OR gate 16 and the AND gate. Applied to drive circuit 20 via gate 18 or AND gate 19 Therefore, the rotor 22 is fast-forwarded by normal rotation and the pointer position is corrected. When the push button 34 is released, it is urged by a spring (not shown) and the switch S2 is connected to VSS again, and the pointer position correcting operation is not performed. Note that when the pushing operation of the push button 34 is released in less than 1 second, only one pulse is generated. Thereafter, when the crown 33 is pushed in, the switch S1 is connected to VSS again, the reset of the frequency dividing circuit 2 is released, and the normal hand movement state is obtained. When the crown 33 is pulled out to the second stage and rotated, the position of only the minute hand 31 and the hour hand 32 can be corrected through a reverse wheel train as in a general timepiece. Further, when the crown 33 is pulled out to the second stage, the push buttons 34 and 35 cannot be pushed in by the action of levers (not shown).
[0017]
Next, the case where the step motor reversely rotates to correct the pointer position will be described.
[0018]
After pulling out the crown 33 as the first external operation member shown in FIG. 3, when the push button 35 as the third external operation member shown in FIG. 3 is pushed, the switch S3 is connected to VDD and H The signal is applied to the low-voltage fast-forward pulse generating circuit 6 via the reverse rotation pulse generating circuit 7 and the OR gate 24. When the button is kept pressed for 1 second or longer, output signals are continuously generated from the reverse rotation pulse generation circuit 7 and the low-voltage fast-forward pulse generation circuit 6 and applied to the AND gate 15 and the AND gate 14 , respectively. However, since the power supply voltage is 1.2 V or more, the AND gate 14 is in the off state and the AND gate 15 is in the on state, and only the output signal of the reverse rotation pulse generating circuit 7 is the OR gate 16 and The voltage is applied to the drive circuit 20 via the AND gate 18 or the AND gate 19. Therefore, the rotor 22 is fast-forwarded by reverse rotation and the pointer position is corrected. When the pushing state of the push button 35 is released, the push button 35 is biased by a spring (not shown), the switch S3 is connected to VSS again, and the pointer position correcting operation is not performed. When the push-in operation of the push button 35 is released within 1 second, only one set of reverse rotation pulses is generated. Thereafter, when the crown 33 is pushed in, the switch S1 is connected to VSS again, the reset of the frequency dividing circuit 2 is released, and the normal hand movement state is obtained.
[0019]
Next, the operation of normal hand movement when the power supply voltage is less than 1.2V will be described.
[0020]
When the power supply voltage becomes less than 1.2 V, the L signal, that is, the low voltage discrimination signal is generated from the voltage level discrimination circuit 9, the AND gate 11 of the control circuit 10 is turned off, and the AND gate 12 is turned on. Therefore, this time, a hand movement pulse which is an output signal of the low voltage hand movement pulse generating circuit 4 is applied to the drive circuit 20 via the OR gate 16 and the like. Therefore, a reverse current flows alternately through the coil 21, and the rotor 22 rotates in the forward direction with an irregular feed every 2 seconds. This rotation drives the second hand 30, the minute hand 31, and the hour hand 32 shown in FIG. Since it is an irregular movement every 2 seconds, the user knows that the power supply voltage has been lowered.
[0021]
Next, the pointer position correcting operation when the power supply voltage is less than 1.2 V will be described. First, the case where the push button 34 is pushed in to correct the pointer position will be described.
[0022]
When the crown 33 shown in FIG. 3 is pulled out to the first stage, the output signals of the hand movement pulse generation circuit 3 and the low voltage hand movement circuit 4 are not generated as described above. Next, when the push button 34 shown in FIG. 3 is continuously pressed, output signals are continuously generated from the fast-forwarding pulse generation circuit 5 and the low-voltage fast-forwarding pulse generation circuit 6 as described above, and the AND gate 13, Applied to the AND gate 14. However, since the power supply voltage is less than 1.2 V, the AND gate 13 is turned off and the AND gate 14 is turned on, and the output signal of the low-voltage fast-forward pulse generating circuit 6 is OR gate. Applied to the drive circuit 20 via the gate 16 and the like. For this reason, the rotor 22 is fast-forwarded in the forward rotation to correct the pointer position. Since the pulse width at this time is wider than the pulse width at 1.2V or more and the drive frequency is low, the step motor operates normally up to about 0.8V. When the push button 34 is released, the switch S2 is again connected to VSS, and the pointer position correcting operation is not performed. Thereafter, when the crown 33 is pushed in, the switch S1 is again connected to VSS, the reset of the frequency dividing circuit 2 is released, and an irregular hand movement state is made every 2 seconds.
[0023]
Next, a case where the push button 35 is pushed in to correct the pointer position when the power supply voltage is less than 1.2V will be described.
[0024]
When the push button 35 is continuously pushed after the crown 33 shown in FIG. 3 is pulled out, output signals are continuously generated from the low-voltage fast-forward pulse generation circuit 6 and the reverse rotation pulse generation circuit 7 as described above. The voltages are applied to the AND gate 14 and the AND gate 15, respectively. However, since the power supply voltage is less than 1.2 V, the AND gate 14 is in the on state and the AND gate 15 is in the off state, and only the output signal of the low-voltage fast-forward pulse generating circuit 6 is the OR gate. 16 is applied to the drive circuit 20 via 16 or the like. For this reason, the rotor 22 is fast-forwarded in the forward rotation to correct the pointer position. That is, even if the push button 35 is depressed, the reverse rotation operation is not performed at a voltage lower than 1.2V. When the push button 35 is released, the switch S3 is again connected to VSS, and the pointer position correcting operation is not performed. Thereafter, when the crown 33 is pushed in, the switch S1 is again connected to VSS, the reset of the frequency dividing circuit 2 is released, and an irregular hand movement state is made every 2 seconds.
[0025]
Although the forward rotation fast forward operation and the reverse rotation operation of the step motor in the above embodiment have been described by taking the case of correcting the position of the time display hand as an example, the gist of the present invention is not necessarily limited to this, and the present invention is not limited thereto. Various modifications can be made without departing from the scope of the present invention. For example, application to correction of the position of an alarm time display hand, return to the initial position of a hand for a stopwatch in an electronic timepiece having a stopwatch function, is included in the gist of the present invention.
[0026]
【The invention's effect】
As is apparent from the above description, according to the present invention, when the power supply voltage becomes a predetermined voltage or lower, the reverse rotation operation of the step motor, which is difficult to operate normally at a low voltage, is prohibited, and the forward drive pulse width is further increased. Since it is widened and the driving speed is slow, the step motor operates stably even at a low voltage, and the effect is great.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of an electronic timepiece showing an embodiment of the present invention.
FIG. 2 is an output waveform diagram of a main part of the circuit block diagram shown in FIG. 1;
FIG. 3 is an external view of an electronic timepiece showing an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 3 Hand movement pulse generation circuit 5 Rapid feed pulse generation circuit 6 Low voltage rapid feed pulse generation circuit 7 Reverse rotation pulse generation circuit 9 Voltage level discrimination circuit 10 Control circuit

Claims (7)

A pulse operation means for generating a normal hand movement pulse , at least a forward rotation fast-forward pulse and a reverse rotation pulse , and a step motor for performing normal rotation, fast-forward normal rotation and reverse rotation in accordance with these pulses ; wherein the plurality of selectively said stepper either pulse - in the electronic timepiece and a control means for supplying the motor, the voltage level discriminating circuit for discriminating the level of the power supply voltage provided, the supply voltage is a predetermined voltage If the voltage determination signal from the voltage level discriminating circuit out of range occurs, the control means the stepper of the reverse rotation pulse - while prohibiting the supply of the motor, the forward rotation fast-forward pulse in place of the reverse rotation pulse An electronic timepiece characterized in that it can be supplied to the step motor . The forward rotation fast-forward pulse supplied to the step motor instead of the reverse rotation pulse by the control means is such that the power supply voltage is wider and lower in frequency than the forward rotation fast-forward pulse within the predetermined voltage range. The electronic timepiece according to claim 1. Pulse generating means for generating a normal hand movement pulse, a forward rotation fast-forwarding pulse, a reverse rotation pulse, a low-voltage hand movement pulse, and a low-voltage forward rotation fast-forwarding pulse, and normal rotation according to these pulses , A step motor for performing each of the forward feed forward rotation and the reverse rotation, a control means for selectively supplying these pulses to the step motor, and a voltage level discrimination for discriminating the level of the power supply voltage and controlling the control means Circuit and
When the power supply voltage is in a predetermined voltage range, the control means supplies any one of the hand movement pulse, forward rotation fast-forward pulse, and reverse rotation pulse to the motor, and the power supply voltage is out of the predetermined voltage range. When a voltage determination signal is generated from the voltage level determination circuit, the control means supplies either one of the low-voltage hand movement pulse and the low-voltage forward rotation fast-forward pulse to the motor. Electronic clock. Power supply, oscillation circuit, drive pulse generating means, drive motor for driving the pointer in response to the drive pulse output from the drive pulse generating means, drive circuit for controlling the drive of the drive motor, drive circuit for controlling the drive circuit An electronic timepiece comprising a control means, wherein the drive pulse generating means generates a normal hand drive drive pulse generating circuit for generating a normal hand drive drive pulse, and generates a non-normal hand drive drive pulse different from the normal hand drive drive pulse. A non-ordinary hand movement drive pulse generation circuit, and a non-appropriate state detection means for detecting the occurrence of a state in which the drive motor cannot be driven properly under a predetermined condition; In response to the detection signal output from the means, the control mode change instruction that instructs the drive circuit control means to prohibit the output of the non-normal hand movement drive pulse. Have a means, the non-normal hand driving pulse is characterized that it is a reverse rotation pulse electronic timepiece. Further, an alternative non-normal hand movement drive pulse generation circuit for generating an alternative non-normal hand movement drive pulse is provided, and when the output of the non-normal hand movement drive pulse is prohibited, the alternative non-normal hand movement drive pulse is supplied to the motor. 5. The electronic timepiece according to claim 4 , wherein the alternative non-normal hand movement drive pulse is a forward rotation rapid feed pulse . A pulse operation means for generating a normal hand movement pulse, at least a forward rotation fast-forward pulse and a reverse rotation pulse, and a step motor for performing normal rotation, fast-forward normal rotation and reverse rotation in accordance with these pulses; An electronic timepiece having control means for selectively supplying any one of the plurality of pulses to the step motor is provided with a voltage level determination circuit for determining the level of the power supply voltage, and the power supply voltage is in a predetermined voltage range. When a voltage discrimination signal is generated from the voltage level discrimination circuit, the control means prohibits the supply of the reverse rotation pulse to the step motor, and at the same time the forward rotation fast-forwarding pulse is changed from the power supply voltage to the predetermined voltage. An electronic timepiece characterized in that the pulse is wider and lower in frequency than the forward rotation fast-forward pulse within the range . 7. The electronic timepiece according to claim 1, further comprising a secondary battery as a power source .

Images