JP2000075063A - Analog electronic clock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To normally operate a load compensation system, and to reduce current consumption by providing a sensitivity-switching means for allowing the detection sensitivity on detection operation after the rotary state of a rotor is detected in the detection operation to differ from a first detection sensitivity. SOLUTION: Detection sensitivity is changed when a rotary detection signal is obtained in detection operation, and, for example, 13 ms passes after a normal driving pulse is applied. Immediately after the application of the normal driving pulse is completed, transistors 9 and 10 of a driving circuit 8 are on. On the other hand, when, for example, 7 ms passes from the application of the pulse, the detection pulse from a pulse generation circuit 5 passes through a control circuit 7, and is applied to the transistor 10 of the driving circuit 8. At the same time, the detection pulse passing through a signal line F from a detection control circuit 24 is applied to a second control transistor 20, a terminal 02 is grounded via a detection resistor 16, and the terminal 02 generate voltage being amplified by transient phenomenon. During the detection operation, the detection sensitivity is changed, thus preventing malfunction even when various second hands are mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an analog electronic timepiece having a step motor.

[0002]

2. Description of the Related Art The battery life of a recent analog electronic timepiece having a stepping motor is significantly longer than in the past. This largely depends on the increase in the capacity of the battery and the reduction in the current consumption of the circuit. However, the reduction in the current consumption by the load compensation function of the step motor is more significant. The load compensation function referred to here refers to a method in which the step motor is normally driven with a small driving force, and the step motor is driven with a large driving force only when the load increases.

The above-described load compensation function intermittently opens and closes a loop including a coil of a step motor after the application of a normal driving pulse, detects an induced voltage generated in the coil by free vibration of the rotor at this time, and detects the detected voltage. Generally, the rotation and non-rotation of the rotor are detected by a signal, and when the rotation is detected, the rotor is normally rotated by a correction drive pulse of a large driving force. Appropriate known documents disclosing this technology include, for example, Japanese Patent Publication No. 1-4395 and Japanese Patent Publication No. 8-33457.

A general analog electronic timepiece is shown in FIG.
The time is displayed by three hands of an hour hand 60, a minute hand 61 and a second hand 62 as shown in FIG.
There is also a specially designed clock with a transparent disk 63 attached instead. This disk 63 (hereinafter referred to as a second disk) has a much larger moment of inertia than a normal second hand,
When used in a timepiece having the load compensation function described above, the rotation and non-rotation of the rotor are not accurately detected, and the timepiece is delayed. The reason for this is that despite the fact that the rotor could not rotate normally, the second disk having a large moment of inertia caused a large rebound, and an induced voltage similar to that of a normal rotation was generated. This is not limited to the second disk, and the same result is obtained with the second hand having a large moment of inertia.

The present applicant has found that the above problem can be solved by switching the detection sensitivity for detecting rotation and non-rotation of the rotor during the detection operation. Japanese Patent Application Laid-Open No. Sho 56-43575 discloses a document which discloses a technique for switching the detection sensitivity.
And JP-A-58-86480.

[0006]

However, the technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 56-43575 discloses an electronic timepiece, such as a lithium battery, in which the power supply voltage changes, the detection sensitivity of which changes according to the change in the power supply voltage. The technology disclosed in Japanese Patent Application Laid-Open No. Sho 58-86480 relates to a technology for automatically setting an appropriate detection sensitivity, and both of them relate to a technology for switching the detection sensitivity during a detection operation. Not something. Therefore, the above-mentioned problems cannot be solved by the techniques disclosed in these documents.

An object of the present invention is to eliminate the above-mentioned conventional disadvantages,
An object of the present invention is to provide an analog electronic timepiece that can operate a load compensation system normally even when a second hand or a second disk having a large moment of inertia is attached, thereby reducing current consumption.

[0008]

An analog electronic timepiece according to the present invention has a step motor including a rotor, a stator, and a coil, and a drive induced in the coil by free vibration of the rotor after application of a normal drive pulse. A first detection operation for determining and detecting the rotation state of the rotor based on a current value in the same direction as the current; and after the first detection operation, a rotation state of the rotor based on a current value in a direction opposite to the drive current. In the analog electronic timepiece having the second detection operation for performing the determination detection, if the rotation state of the rotor is detected during the first detection operation, the detection sensitivity during the second detection operation thereafter Is provided with detection sensitivity switching means for making the detection sensitivity different from the detection sensitivity at the time of the first detection operation.

The detection of the rotation state of the rotor is performed by converting a current value to a voltage value and determining the magnitude of the voltage value. The detection sensitivity switching means includes a resistance of a detection resistor. The switching is performed by switching the value, or by switching and connecting a high and low Vth detection circuit to the coil.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of an example of an embodiment of the present invention, and FIG. 2 is an output waveform diagram of a main part thereof. In FIG. 1, reference numeral 1 denotes an oscillation circuit, and reference numeral 2 denotes a frequency dividing circuit. By combining outputs from various output stages of the frequency dividing circuit 2, a signal necessary for clock driving is created.

Reference numeral 3 denotes a normal drive pulse generation circuit,
The normal drive pulse as shown in FIG. 3A is output every second. This normal drive pulse has a pulse width of 6 ms and a duty 18/32 to a duty 25/32 divided every 1 ms.
Are prepared, and one of the pulses is appropriately output. Note that the chopper pulse shown in FIG. 2A is not accurately divided as described in the text due to the drawing, and the same applies to other chopper pulses described below.

Reference numeral 4 denotes a correction drive pulse generation circuit,
The latter half as shown in (c) is the pulse width 13 of the chopper pulse.
ms correction drive pulse is generated. This correction drive pulse is a normal drive pulse, and is used only when the rotor 14 of the step motor cannot be normally driven.
The voltage is applied to the driving circuit 8 described later 2 ms later.

A detection pulse generating circuit 5 generates a series of detection pulses having a width of 32 μs as shown in FIG. 2B every 1 ms. This detection pulse is generated from 7 ms to 25 ms starting from the time when the normal drive pulse is applied. After the normal drive pulse is applied, the connection state of both ends of the step motor coil 13 is opened and closed intermittently. Serve to get out. Reference numeral 6 denotes a counter circuit which counts the number of pulses of the detection pulse generation circuit 5 and, after the count is completed, outputs a HIGH signal (hereinafter referred to as an H signal) instead of a LOW signal (hereinafter referred to as an L signal) from an output line D after the count is completed. Output).

Reference numeral 7 denotes a drive control circuit, which is a detection circuit 2 described later.
Based on the information from No. 3, it controls which duty of the normal drive pulse is to be applied to the drive circuit 8 to be described later, and whether or not the correction drive pulse is to be applied to the drive circuit 8 after passing.
The drive circuit 8 is composed of two well-known P-channel MOS transistors (hereinafter referred to as transistors) 9 and 10 and two N-channel MOS transistors (hereinafter referred to as transistors) 11 and 12. The coil 13 is connected to the output terminals O1 and O2. The rotor 14 rotates by one step (180 °) each time an alternating current flows in the coil 13 in the direction of the solid arrow and the direction of the dotted arrow.

A first detection resistor 15 has one end connected to the terminal O 1 and the other end grounded via a first control transistor 19. 16 is a second detection resistor, one end of which is connected to a terminal O2.
And the other end is grounded via the second control transistor 20. The first detection resistor 15 and the second detection resistor 16 have a relatively small value of 10 KΩ. A third detection resistor 17 has one end connected to the terminal O1 and the other end connected to the third detection resistor.
It is grounded via a control transistor 21. A fourth detection resistor 18 has one end connected to the terminal O2 and the other end grounded via a fourth control transistor 22. The third detection resistor 17 and the fourth detection resistor 18 have a relatively large value of 60 KΩ. The detection pulse generation circuit 5, the counter circuit 6, the first detection resistor 15, the second detection resistor 16,
The detection sensitivity switching means includes the third detection resistor 17, the fourth detection resistor 18, the first control transistor 19, the second control transistor 20, the third control transistor 21, the fourth control transistor 22, a detection control circuit 24 described later, and the like. Have been.

Reference numeral 23 denotes a detection circuit which detects the rotation or non-rotation of the rotor 14 based on the current flowing through the coil 13 after the application of the drive pulse, and sends the information to the drive control circuit 7 and a detection control circuit 24 to be described later. I have. Reference numeral 24 denotes a detection control circuit, which outputs an output signal of the signal line A of the drive control circuit 7 and the detection circuit 2
3 and the signal line D of the counter circuit 6
, And selects one of the signal lines E, F, G, and H to output a detection pulse from the detection pulse generation circuit 5. Here, when the signal line A is the H signal and the signal lines B and D are the L signals, the signal line F is selected. When the signal line A is the H signal and the signal line B or the signal line D is the H signal, the signal is selected. When the line G is selected, the signal line A is an L signal and the signal lines B and D are L signals, the signal line E is selected, the signal line A is an L signal, and the signal line B or the signal line D is an H signal. In this case, the signal line H is selected.

Next, the operation will be described. In order to facilitate understanding of the present invention, the essential points of the detection operation will first be briefly described with reference to FIG. 3, and then will be described in detail.

The detecting operation is performed by first driving the driving current 30 shown in FIG.
The operation starts from a first detection operation of detecting a hatched portion current 31 which is a current in the same direction as the above as a voltage. The detection circuit 23 at this time
Is in a state where the detection sensitivity is low, that is, the detection signal is relatively hard to exceed Vth of the detection circuit 23. However, if the rotation detection signal is not obtained in the first detection operation even when 12 ms elapses from the application of the normal drive pulse, the detection sensitivity switches to a high state from the time when 13 ms elapses after the application of the normal drive pulse.

If a rotation detection signal exceeding Vth of the detection circuit 23 is obtained in the first detection operation, the driving current 30
And a second detection operation of detecting the hatched current 32, which is the reverse current, as a voltage. The detection sensitivity of the detection circuit 23 at the time of the second detection operation is always high, that is, the detection signal relatively easily exceeds Vth of the detection circuit 23. Only when a rotation detection signal is obtained in the second detection operation, a final determination that the rotor 14 has normally rotated is made. If the rotation detection signal is not obtained in the second detection operation, it is finally determined that the rotor 14 has not normally rotated and has not rotated.

The detection sensitivity is switched in this manner when the rotation detection signal is obtained in the first detection operation and when 13 ms elapses from the application of the normal drive pulse.

Next, the operation will be described in detail. It is assumed that a normal second hand (a moment of inertia of about 55 milligram square millimeter) is attached, the duty of the normal drive pulse applied to the drive circuit 8 is 19/32, and a current flows through the coil 13 in the direction of the solid arrow. It is assumed that the current waveform at that time is as shown in FIG. When a current flows through the coil 13 in the direction of the solid arrow, the drive control circuit 7
An H signal is output to the signal line A from the, and an L signal is output to the signal line A when a current flows in the direction of the dotted arrow.

After a lapse of 7 ms from the application of the normal drive pulse, a series of detection pulses as shown in FIG. 2 (b) are applied to the drive circuit 8 through the drive control circuit 7 to check whether the rotor 14 has rotated normally. The determination is made by the detection circuit 23. As described above, this determination operation is started from the first detection operation in which the hatched portion current 31 which is the same current as the drive current 30 shown in FIG. 3 is detected as a voltage.

Immediately after the end of the normal driving pulse application, the driving circuit 8
Are turned on, the detection pulse from the detection pulse generation circuit 5 passes through the drive control circuit 7 when 7 ms elapses from the application of the normal drive pulse, and the transistor 10 of the drive circuit 8 , And at the same time, a detection pulse that has passed through the signal line F from the detection control circuit 24 is applied to the second control transistor 20, and the terminal O2 is grounded via the second detection resistor 16. Therefore, a voltage amplified by the transient phenomenon occurs at the terminal O2. FIG. 4 shows a voltage waveform generated at the terminal O2 at this time. V1
Since the signal does not exceed Vth (threshold) of the detection circuit 23, voltage detection in the same direction is further performed. Vt signal is also Vt
h, and voltage detection in the same direction is performed.

Since the V3 signal has exceeded Vth for the first time, a second detection operation for detecting, as a voltage, a hatched portion current 32 which is a reverse current to the drive current 30 shown in FIG. 3 is performed. When an H signal based on the V3 signal serving as the rotation detection signal shown in FIG. 4 is applied from the detection circuit 23 to the drive control circuit 7 through the signal line B, the detection pulse passed through the drive control circuit 7 is output to the drive circuit 8 The switching is applied from the transistor 10 to the transistor 9. At the same time, the detection control circuit 24 is controlled by the H signals of the signal lines A and B, outputs a detection pulse from the signal line G, and applies it to the third control transistor 21.

This time, the third detection resistor 1 having a relatively high resistance value
Since the terminal O1 is grounded via the terminal 7, the detection sensitivity is increased. FIG. 5 shows a voltage waveform generated at the terminal O1 at this time. V4 signal and V5 signal do not exceed Vth and V6
The signal exceeds Vth for the first time. At this time, the detection circuit 23 determines that the rotor 14 has rotated normally, outputs an H signal from the signal line C, and applies it to the drive control circuit 7. Upon receiving this result, the drive control circuit 7 prohibits the passage of the detection pulse and the correction drive pulse thereafter, so that the stepping motor is not driven by the correction drive pulse. By the next step, the counter circuit 6, the detection circuit 23 and the like are reset by a clock pulse (not shown). Note that the first detection resistor 15 and the fourth detection resistor 18 do not participate in the above detection operation.

The same operation is performed in the next step (after one second). In this case, a current flows through the coil 13 shown in FIG. First, the drive control circuit 7 to the transistor 9
Since the signal line A is an L signal and the signal lines B and D are L signals, the detection control circuit 24 selects the signal line E and applies a detection pulse to the first control transistor 19. When a rotation detection signal exceeding Vth of the detection circuit 23 is detected, the signal line B becomes an H signal, so that the detection pulse is switched to the transistor 10 and the fourth control transistor 2.
2 is applied. When a final determination result indicating that the rotor 14 has rotated normally for a certain period of time (for example, four minutes) is sent to the drive control circuit 7, the drive control circuit 7 causes the normal drive pulse generation circuit 3 to rank one rank from the next step. A command to output a pulse of duty 18/32 in which the driving energy is reduced only is sent. Therefore, in the next step, duty 18/32
The stepping motor is driven by the normal driving pulse of.

FIG. 6 shows a current waveform when driven at duty 18/32. After a lapse of 7 ms from the application of the normal drive pulse, a series of detection pulses as shown in FIG. 2B are applied to the drive circuit 8 through the detection control circuit 24 and the drive control circuit 7, and the rotor 14 is turned on. The detection circuit 23 determines whether or not the rotation is normal. As described above, the determination operation is first started from the first detection operation shown in FIG. 6 in which a current in the same direction as the drive current is detected as a voltage. FIG. 7 shows a voltage waveform generated at the terminal O2 at this time. Since the V1 signal does not exceed Vth of the detection circuit 23, voltage detection in the same direction is further performed. V2 signal and V3 signal
th and voltage detection in the same direction is performed.

Since Vth has exceeded Vth for the first time with the V4 signal, a second detection operation for detecting, as a voltage, a current in the opposite direction to the drive current shown in FIG. 6 is performed. FIG. 8 shows a voltage waveform generated at the terminal O1 at this time, but the V5 signal to the V14 signal do not exceed Vth. Here, the detection operation is stopped 10 ms after the detection of the V4 signal serving as the rotation detection signal in FIG. 7, that is, the detection operation is stopped when the V14 signal in FIG. 8 is detected. This means that the detection signal has not been detected. The detection circuit 23 determines that the rotor 14 did not rotate normally, that is, determined that it was not rotating, and the signal line C remains at the L signal. V5
In the detection operation after the signal, the detection pulse is applied to the transistor 9 and the third control transistor 21. Therefore, the detection sensitivity is higher after V5 signal detection than before.

When the drive control circuit 7 receives the non-rotation information, it immediately permits the passage of the correction drive pulse, and the rotor 14 is driven normally by the correction drive pulse, rotates normally, and cannot be rotated by the normal drive pulse drive. Is immediately resolved. In the next step (one second later), the driving energy is controlled by the control signal from the drive control circuit 7, and the drive energy from the normal drive pulse generation circuit 3 is increased by one rank.
A 19/32 normal drive pulse is generated, and the step motor is driven by this pulse. This dut
If the rotor 14 cannot rotate normally due to a heavy load during the driving by the normal driving pulse of y19 / 32, the rotor 14 is promptly rotated normally by the correction driving pulse,
In the next step, the driving energy is increased by one rank.
The stepping motor is driven by the normal driving pulse of 20/32. If the load is further heavy, the drive is driven by the normal drive pulse whose drive rank is raised one after another. If non-rotation is detected even with the normal drive pulse of duty 25/32 having the maximum drive energy, the drive is performed by the normal drive pulse of duty 18/32 with the minimum drive energy in the next step. Is configured.

Next, the normal second hand described above is attached,
The operation when driven by the normal drive pulse of duty 22/32 will be described.

FIG. 9 shows a current waveform at this time. The phase of the current waveform after the end of the application of the normal drive pulse is earlier and closer to the drive current than the current waveform when driven by the normal drive pulse of duty 19/32 shown in FIG. This phenomenon occurs when the moment of inertia of the rotor is small.
Appears when the second hand is not attached. Therefore, most of the driving current and the current in the opposite direction are within 13 ms from the time of applying the normal driving pulse. 13 ms after the application of the normal drive pulse is a position where the detection sensitivity is switched when the rotation detection is not performed in the first detection operation. Further, similarly to the current waveform shown in FIG. 3, the peak value of the alternating current waveform after the end of the normal drive pulse application gradually decreases, and it is difficult to detect the rotation in the second detection operation compared to the first detection operation. Has become.

FIGS. 10 and 11 show voltage waveforms at the time of the detection operation. The rotation detection by the first detection operation is performed by the V3 signal of FIG. 10, and the rotation detection by the second detection operation is performed by the V5 signal of FIG. Finally, it is determined that the rotor 14 has normally rotated. In the present invention, since the detection sensitivity is switched from the point of detection of the V4 signal, the rotation detection is relatively easily performed even if the peak value of the current is small. In the above example, it is not necessary to switch the detection sensitivity after a lapse of 13 ms from the application of the normal drive pulse.

Here, unlike the present invention, a case will be described in which the detection resistance remains unchanged at 10 KΩ even when the rotation detection is performed in the first detection operation, that is, the detection sensitivity is not switched.
When the current waveform driven by the normal drive pulse of duty 22/32 shown in FIG. 9 is detected as a voltage, the detected resistance value varies and the other components vary even though the rotor 14 is rotating normally. Depending on the second
Non-rotation detection is performed in the detection operation. Especially rotor 14
If there is a variation in the moment of inertia of
In some cases, non-rotational detection may be performed even when driving with the normal drive pulse of y21 / 32. When non-rotational detection is performed by driving with a normal drive pulse of duty 22/32, duty 23/32 in the next step, and further duty 24/3
Second, non-rotational detection is also performed in the case of driving with a normal driving pulse of duty 25/32. As described above, when non-rotation detection is performed by driving with the normal drive pulse of duty 25/32, the next step is duty1.
Driving is performed by an 8/32 normal driving pulse (see FIGS. 6, 7, and 8). In this case, non-rotational detection is performed due to insufficient driving energy, and duty 19 /
Rotation detection is performed by driving with 32 normal driving pulses (see FIGS. 3, 4, and 5).

Accordingly, even in this case, although there is no problem in the end, it is preferable to detect the rotation when the rotor 14 rotates normally. For example, in the production line, the current consumption is inspected in a short time without attaching the second hand, but the rotor is driven by the normal drive pulse of duty 21/32 which has a margin for driving. In this case, if non-rotational detection is performed, the consumption of current is greatly increased due to the generation of the correction drive pulse, which is not preferable because it is determined to be defective. In the present invention, since the detection sensitivity is switched after the first detection operation, the rotation detection can be easily performed in the second detection operation even if there is some variation in components.

Next, the operation when a second disk having a large moment of inertia as shown in FIG. 27 is mounted will be described.

FIG. 12 shows a diameter of 17 mm and a thickness of about 0.1 m.
m, a specific gravity of 1.4 seconds disk (moment of inertia of about 1150 milligram square millimeter) attached and duty22
It is a current waveform when the rotor 14 is driven normally by the / 32 normal drive pulse and the rotor 14 rotates normally.

FIG. 13 shows a voltage waveform generated at the terminal O2 at this time. The V1 signal to V4 signal do not exceed Vth, and the rotation detection signal exceeding Vth is obtained for the first time with the V5 signal, and the detection terminal is switched. FIG. 14 shows a voltage waveform generated at the terminal O1. The V6 signal to the V8 signal do not exceed Vth and the V9 signal exceeds Vth for the first time. The detection after the V6 signal involves the third detection resistor 17 of 60 KΩ, and the detection sensitivity is higher than before. At this point, an H signal, which is a rotation detection signal indicating that the rotor 14 has rotated normally, is applied from the detection circuit 23 to the drive control circuit 7 through the signal line C, and the drive control circuit 7 passes the subsequent detection pulses. And the detection operation in that step is stopped, and the passage of the correction drive pulse is also prohibited.

Thereafter, the same operation is performed, and when a result of the determination that the motor has normally rotated continuously for a predetermined time (for example, 4 minutes) is sent to the drive control circuit 7, the drive control circuit 7 generates a normal drive pulse. A command is sent to the circuit 3 to output a normal drive pulse of duty 21/32 in which the drive energy is reduced by one rank from the next step. Therefore, in the next step, the step motor is driven by the normal drive pulse of duty 21/32. In the above example, there is no need to switch the detection sensitivity after a lapse of 13 ms from the application of the normal drive pulse.

Here, unlike the present invention, a case will be described in which the detection resistance is kept at 10 KΩ and the switching is not performed, that is, the detection sensitivity is not switched in the second detection operation. In this case, the V9 signal shown in FIG. 14 cannot exceed Vth, and no signal exceeding Vth is detected thereafter.
Even though the rotor 14 is rotating normally, it is determined that the rotor 14 is not rotating, and a correction drive pulse is generated. In the next step, the drive rank rises and wasteful current is consumed.

FIG. 15 shows the state in which the above-mentioned second disk is attached and dut is performed.
This is a current waveform in a case where the rotor 14 is not normally rotated when driven by a normal drive pulse of y21 / 32.

FIG. 16 shows a voltage waveform generated at the terminal O2 at this time. The signals V1 to V8 do not exceed Vth, and the rotation detection signal exceeding Vth is obtained for the first time with the V9 signal, and the detection terminals O2 and O1 are switched. FIG. 17 shows a voltage waveform generated at the terminal O1, and the V10 signal to the V19 signal do not exceed Vth. As described above, since the third detection resistor 17 and the fourth detection resistor 18 of 60 KΩ are involved in the detection after the V7 signal, the detection sensitivity is higher than before. Since the detection pulse is terminated at the time when 25 ms has elapsed from the application of the normal drive pulse, the detection operation is stopped at this time, and the L signal which is the non-rotation detection signal indicating that the rotor 14 did not rotate normally is output via the signal line C. Detection circuit 2
3 is applied to the drive control circuit 7. Therefore, the correction drive pulse quickly passes through the drive control circuit 7 and the drive circuit 8
And the rotor 14 is driven by this correction drive pulse and rotates normally. In the next step (after one second), the driving signal is controlled by the control signal from the driving control circuit 7, and the normal driving pulse generating circuit 3 generates a normal driving pulse of duty 22/32 with the driving energy higher by one rank. The stepping motor is driven by the driving pulse.

Here, a case where only 60 KΩ is used instead of 10 KΩ as the detection resistance and the detection resistance is not switched in the middle of the detection operation as in the prior art, that is, the case where the detection sensitivity is not switched will be described. In this case, the voltage conversion signals of the same direction current and the opposite direction current as the drive current shown in FIG. 15 have high detection sensitivity, so that both exceed Vth, and although the rotor 14 does not rotate normally, As a result, a time delay, which is a fatal defect in a clock, occurs.

Next, the operation when a second disk having a larger moment of inertia is mounted will be described.

FIG. 18 shows a diameter of 20 mm, a thickness of 0.1 mm,
Attach a disk with a specific gravity of 1.4 (moment of inertia of about 2200 milligrams square millimeter) and attach it to a duty 23/3.
2 is a current waveform when the rotor 14 is driven by two normal drive pulses and the rotor 14 rotates normally.

FIG. 19 shows a voltage waveform generated at the terminal O2 at this time. The V1 signal to the V8 signal do not exceed Vth, and the rotation detection signal exceeding Vth is obtained for the first time with the V9 signal, and the detection terminal is switched. As described above, since the output of the counter circuit 6 is switched to the H signal in the detection after the V7 signal, the third detection resistor 17 of 60 KΩ is used.
And the fourth detection resistor 18 is involved, and the detection sensitivity is higher than before. Therefore, the V5 signal involving 10 KΩ and the V9 involving 60 KΩ, which are voltage conversions of almost the same peak current,
The signal has a different voltage level, and does not exceed Vth for the V5 signal and exceeds Vth for the V9 signal. FIG. 20 shows the terminal O
This is the voltage waveform generated at 1 and does not exceed Vth for the V10 signal and V11 signal, and exceeds Vth for the V12 signal for the first time. At this point, it is finally determined that the rotor 14 has normally rotated. In this case, 13
The effect of switching the detection sensitivity after ms appears.

Thereafter, the same operation is performed. When a result of the determination that the motor has normally rotated continuously for a predetermined time (for example, 4 minutes) is sent to the drive control circuit 7, the drive control circuit 7 generates a normal drive pulse. A command is sent to the circuit 3 to output a normal drive pulse of duty 22/32 in which the drive energy is reduced by one rank from the next step. Therefore, in the next step, the step motor is driven by the normal drive pulse of duty 22/32.

Here, unlike the present invention, a case will be described in which the detection resistance is kept at 10 KΩ during the detection operation and the switching is not performed, that is, the detection sensitivity is not switched. In this case, the V9 signal shown in FIG. 19 cannot exceed Vth similarly to the V5 signal, and no signal exceeding Vth is detected thereafter, even if the rotor 14 is rotating normally. Regardless, it is determined that the motor is not rotating, and a correction drive pulse is generated. In the next step, the drive rank rises, and wasteful current is consumed.

FIG. 21 shows a state in which the second disk is attached and dut is attached.
It is a current waveform when the rotor 14 is not able to rotate normally when driven by a normal drive pulse of y22 / 32.

FIG. 22 shows a voltage waveform generated at the terminal O2 at this time. The V1 signal to the V10 signal do not exceed Vth, and the rotation detection signal exceeding Vth is obtained for the first time with the V11 signal, and the detection terminals O2 and O1 are switched. FIG. 23 shows a voltage waveform generated at the terminal O1.
Vth does not exceed 2 signals to V19 signal. As described above, since the third detection resistor 17 and the fourth detection resistor 18 of 60 KΩ are involved in the detection after the V7 signal, the detection sensitivity is higher than before. 25ms from normal drive pulse application
At this point, the detection pulse is terminated. At this point, the detection operation is stopped, and the L signal, which is a non-rotation detection signal indicating that the rotor 14 did not rotate normally, is controlled by the detection circuit 23 via the signal line C. Applied to the circuit 7. Therefore, the correction drive pulse is promptly applied to the drive circuit 8 through the drive control circuit 7, and the rotor 14 is driven by the correction drive pulse and rotates normally. In the next step (after one second), the driving signal is controlled by the control signal from the driving control circuit 7, and the normal driving pulse generating circuit 3 generates a normal driving pulse of duty 23/32 which is one rank higher in driving energy, and The stepping motor is driven by the driving pulse.

Here, a case will be described in which only 60 KΩ is used instead of 10 KΩ as the detection resistance, and the detection resistance is not switched during the rotation detection operation, that is, the detection sensitivity is not switched, as in the prior art. In this case, FIG.
Since the drive current and the voltage conversion signal of the same direction current and the opposite direction current indicated by (1) have high detection sensitivity, both exceed Vth, and it is determined that the rotor 14 is rotating even though the rotor 14 is not rotating normally. No correction drive pulse is generated, and a time delay, which is a fatal defect for a clock, occurs.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 24, those having the same function as FIG.
The same numbers as the numbers shown in FIG. In addition, since the components from the oscillation circuit 1 to the rotor 14 shown in FIG. 24 are almost the same as those shown in FIG. 1, the description is omitted, and the detection sensitivity switching means which is the gist of the present invention will be described in detail.

First, the case where a drive current flows in the direction of the solid line arrow in the coil 13 will be described with reference to FIG. 24. A detection pulse is applied to the transistor 10 of the drive circuit 8 when 7 ms elapses from the time of application of the normal drive pulse. Therefore terminal O
2, voltage detection is performed. At the same time, the detection control circuit 24 outputs a detection pulse passing through the signal line F because the signal line A is the H signal and the signal line B is the L signal.
Since the detection signal is applied to 0, the detection signal is applied to the terminal IN2 of the detection circuit 23 as a voltage having an appropriate height adjusted by the second detection resistor 16. The detection pulse passing through the signal line F is also applied to the detection circuit 23.

FIG. 25 is a detailed diagram of the detection circuit 23 shown in FIG. In FIG. 24, when a drive current flows through the coil 13 in the direction of the solid arrow, the signal line A is at the H signal and the signal line D is at the L level.
The Q output of the initialized flip-flop 47 is an L signal, and the Q bar output is an H signal. Therefore, the output of the exclusive OR gate 51 to which the signal line A and the Q output of the flip-flop 47 are applied is the H signal,
The output of the exclusive OR gate 52 to which the Q line output of the signal line A and the flip-flop 47 is applied is an L signal, and the output of the OR gate 49 to which the Q output of the signal line D and the flip-flop 47 is applied is an L signal. , OR gate 4
The output of the inverter 50 to which the output of No. 9 is applied is an H signal. Therefore, of the AND gates 54, 55, 56, and 57 to which these signals are applied, only the AND gate 55 is in the ON state.

The detection voltage applied to the terminal IN2 is input to the plus input terminal of the second comparator 41, and the signal line F
The passed detection pulse is applied to the seventh control transistor 49 and the OR gate 43 via the OR gate 53 and the AND gate 55. The divided voltage of the resistors R4 and R5 is applied to the minus input terminal of the second comparator 41,
The H level of the rotation detection signal or the L signal of the non-rotation detection signal is output from the second comparator 41 by comparing the level with the detection voltage applied to the plus input terminal. This detection signal is output from the OR gate 46 via the AND gate 45 at the timing of the detection pulse passing through the OR gate 43.

H, which is a rotation detection signal from the OR gate 46,
If a signal is output, the flip-flop 47 of FIG.
The Q output switches to the H signal and the Q bar output switches to the L signal.
This time, the output of the exclusive OR gate 52 becomes an H signal, and only the AND gate 56 of the AND gates 54, 55, 56, 57 is turned on. The H signal passed through the signal line B is applied to the drive control circuit 7 and the detection control circuit 24 in FIG. 24, and the first detection operation ends. As a result, the detection pulse is switched and applied to the transistor 9 of the drive circuit 8, and the voltage detection at the terminal O1 is performed. At the same time, the detection pulse is switched to the signal line E of the detection control circuit 24 and output, and is applied to the first control transistor 19 and the detection circuit 23. The detection signal generated at the terminal O1 is the first
A voltage having an appropriate height adjusted by the detection resistor 15 is applied to the terminal IN1 of the detection circuit 23. Terminal IN1
The detection signal applied to the first comparator 40 shown in FIG.
Is input to the plus input terminal.

On the other hand, the detection pulse applied to the OR gate 53 of the detection circuit 23 through the signal line E is
Control transistor 48 and OR gate 42 through
Is applied to The detection pulse is the sixth control transistor 48
Is applied to the minus input terminal of the first comparator 40, the divided voltage of the resistor R1 and the resistor R3 is applied, and the level of the detection voltage applied to the plus input terminal is compared with that of the first comparator 40. Outputs the H signal of the rotation detection signal or the L signal of the non-rotation detection signal. This detection signal is applied to the AND gate 44 together with the detection pulse passed through the OR gate 42, and further applied to the flip-flop 47 via the OR gate 46.

The second detection operation is continued within 10 ms after the H signal is generated from the OR gate 46 in the first detection operation and until the H signal is output from the OR gate 46. When the H signal is output, the detection operation is performed. Ends. That is, when the H signal is output from the OR gate 46 in the second detection operation, the signal is also applied to the flip-flop 48, and the H signal is generated on the signal line C. This H signal is applied to the drive control circuit 7
, And the subsequent detection operation stops as described above. The flip-flops 47 and 48 are driven by clock pulses (not shown) until the next normal drive pulse is generated.
Are reset to the initial state.

Here, the resistance values of the resistors R1 and R4 are 2K
Ω, the resistance values of the resistors R2 and R5 are 1 KΩ, and the resistance values of the resistors R3 and R6 are 4 KΩ. Therefore, the detection sensitivity in the second detection operation is higher than the detection sensitivity in the first detection operation. ing. Note that the resistance values of the resistors R1 to R6 are just an example, and are appropriately set so as not to be erroneously detected.

Next, at the time of the first detection operation when a current flows in the direction indicated by the solid line arrow in the coil 13 shown in FIG. 24, one signal is applied to the signal line B until 12 ms elapses from the application of the normal drive pulse.
The case where the H signal is not output again will be described. FIG. 25 until 12 ms elapses after the application of the normal drive pulse.
Of the AND gates 54, 55, 56 and 57 shown in FIG. Therefore, the detection pulse is applied to the seventh control transistor 49,
The voltage divided by the resistors R4 and R5 is applied to the minus input terminal of the comparator 41.

When 13 ms elapses from the application of the normal drive pulse, the counter circuit 6 shown in FIG.
A signal is output. This H signal is applied to the OR gate 49 of the detection circuit 23, and this time the AND gates 54, 55,
Only the AND gate 54 of the transistors 6 and 57 is turned on.
Therefore, the detection pulse is applied to the eighth control transistor 50, and the divided voltage of the resistors R4 and R6 is applied to the minus input terminal of the second comparator 41. The second comparator 41 compares the level of the rotation detection signal with the detection voltage applied to the plus input terminal.
The signal or the L signal of the non-rotation detection signal is output. This detection signal is applied to the flip-flop 47 via the AND gate 45 and the OR gate 46. This detection operation is continued until the H signal is output from the OR gate 46 within a predetermined time.

When the H signal is output from the OR gate 46, the Q output of the flip-flop 47 is the H signal and the Q bar output is the L signal.
Signal. Since the H signal is applied to the signal line D, the AND gate 56 is turned on this time. Since the H signal is output to the signal line B, the detection pulse passed through the drive control circuit 7 is applied to the transistor 9 and the detection pulse passed through the detection control circuit 24 is passed through the signal line E to the first control transistor 9. And the detection circuit 23. Thus, the detection voltage generated at the terminal O1 is applied to the first comparator 40. On the other hand, the detection pulse that has passed through the OR gate 53 of the detection circuit 23 is applied to the sixth control transistor 48 via the AND gate 56.

When the detection pulse is applied to the sixth control transistor 48, the divided voltage of the resistors R1 and R3 is applied to the minus input terminal of the first comparator 40, and the detection voltage applied to the plus input terminal is And the first comparator 40 outputs the H signal of the rotation detection signal or the L signal of the non-rotation detection signal.
4. Flip-flops 47, 4 via OR gate 46
8 is applied. In the first detection operation, the flip-flop 47
Is already outputting an H signal, the H output of the flip-flop 48 becomes the H signal when the H signal is output from the OR gate 46 in the second detection operation. Therefore, this H signal is applied to the drive control circuit 7 through the signal line C,
Subsequent detection operations stop.

As described above, the resistance values of the resistors R1 and R4 are 2 KΩ, the resistance values of the resistors R2 and R5 are 1 KΩ, and the resistance values of the resistors R3 and R6 are 4 KΩ.
The Vth of the first comparator 40 and the second comparator 41 after 13 ms is lower than before, and the detection sensitivity is higher.

Next, a case where rotation is detected by the first detection operation 13 ms after the application of the normal drive pulse and non-rotation is detected by the second detection operation will be described. Since it is considered that the description can be easily understood, the description is omitted. Further, the operation when the drive current flows in the direction of the dotted arrow in the coil 13 will be omitted because it is considered that it can be easily understood from the above description.

Although the present invention has been described above, various modifications can be made without departing from the spirit of the present invention. For example, the detection pulse is generated every 0.5 ms instead of every 1 ms, The present invention includes a case where the number of signals exceeding the threshold value is not one but two or more as rotation detection signals. Further, in the present invention, the detection is performed based on the current value, but it is needless to say that the same is true based on the voltage value.

[0066]

As is apparent from the above description, the present invention is configured so that the detection sensitivity is switched during the detecting operation. Therefore, according to the present invention, the second hand having a large moment of inertia or the second hand having a large moment of inertia is used according to the present invention. It is possible to obtain an analog electronic timepiece that does not malfunction even if a second disk having a large diameter is attached and consumes a small amount of current.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an embodiment of the present invention.

FIG. 2 is an output waveform diagram of a main part of an example of an embodiment of the present invention.

FIG. 3 is a current waveform diagram when a normal second hand is attached and driven by a normal drive pulse of duty 19/32.

4 is a voltage waveform diagram generated at a terminal O2 when the current waveform shown in FIG. 3 is converted into a voltage.

FIG. 5 is a voltage waveform diagram generated at a terminal O1 when the current waveform shown in FIG. 3 is converted into a voltage.

FIG. 6 is a current waveform diagram when a normal second hand is attached and driven by a normal drive pulse of duty 18/32.

7 is a diagram showing a voltage waveform generated at a terminal O2 when the current waveform shown in FIG. 6 is converted into a voltage.

FIG. 8 is a voltage waveform diagram generated at a terminal O1 when the current waveform shown in FIG. 6 is converted into a voltage.

FIG. 9 is a current waveform diagram when a normal second hand is attached and driven by a normal drive pulse of duty 22/32.

10 is a diagram showing a voltage waveform generated at a terminal O2 when the current waveform shown in FIG. 9 is converted into a voltage.

11 is a diagram showing a voltage waveform generated at a terminal O1 when the current waveform shown in FIG. 9 is converted into a voltage.

[FIG. 12] A second disk having a diameter of 17 mm is attached and a duty is set.
It is a current waveform diagram at the time of being driven by the 22/32 normal drive pulse.

13 is a diagram showing a voltage waveform generated at a terminal O2 when the current waveform shown in FIG. 12 is converted into a voltage.

FIG. 14 is a voltage waveform diagram generated at a terminal O1 when the current waveform shown in FIG. 12 is converted into a voltage.

FIG. 15 is a diagram showing a duty with a second disk having a diameter of 17 mm.
It is a current waveform diagram at the time of being driven by the 21/32 normal drive pulse.

16 is a diagram showing a voltage waveform generated at a terminal O2 when the current waveform shown in FIG. 15 is converted into a voltage.

17 is a voltage waveform diagram generated at terminal O1 when the current waveform shown in FIG. 15 is converted into a voltage.

[FIG. 18] A second disk having a diameter of 20 mm is attached and a duty is set.
It is a current waveform diagram at the time of being driven by the 23/32 normal drive pulse.

19 is a diagram showing a voltage waveform generated at a terminal O2 when the current waveform shown in FIG. 18 is converted into a voltage.

FIG. 20 is a voltage waveform diagram generated at terminal O1 when the current waveform shown in FIG. 18 is converted into a voltage.

FIG. 21 is a diagram showing a duty with a second disk having a diameter of 20 mm.
It is a current waveform diagram at the time of being driven by the 22/32 normal drive pulse.

FIG. 22 is a diagram showing a voltage waveform generated at a terminal O2 when the current waveform shown in FIG. 21 is converted into a voltage.

23 is a diagram showing a voltage waveform generated at a terminal O1 when the current waveform shown in FIG. 21 is converted into a voltage.

FIG. 24 is a block diagram of another example of the embodiment of the present invention.

25 is a detailed circuit diagram of the detection circuit 23 shown in FIG.

FIG. 26 is an external plan view of an analog electronic timepiece to which a conventional second hand according to the related art and the present invention is attached.

FIG. 27 is an external plan view of an analog electronic timepiece to which the second disk having a large moment of inertia according to the present invention is attached.

[Explanation of symbols]

 Reference Signs List 3 Normal drive pulse generation circuit 4 Correction drive pulse generation circuit 5 Detection pulse generation circuit 6 Counter circuit 7 Drive control circuit 8 Drive circuit 13 Step motor coil 14 Step motor rotor 15 First detection resistor 16 Second detection resistor 17 Third Detection resistor 18 Fourth detection resistor 19 First control transistor 20 Second control transistor 21 Third control transistor 22 Fourth control transistor 23 Detection circuit 24 Detection control circuit 40 First comparator 41 Second comparator 47 Fifth control transistor 48 Sixth Control transistor 49 Seventh control transistor 50 Eighth control transistor

Claims (6)

[Claims] A step motor including a rotor, a stator, and a coil, wherein the rotor is driven based on a current value in the same direction as a drive current induced in the coil due to free vibration of the rotor after normal drive pulse application is completed. Having a first detection operation for determining and detecting the rotation state of the rotor, and a second detection operation for determining and detecting the rotation state of the rotor based on a current value in a direction opposite to the drive current after the first detection operation. In the electronic timepiece, when the rotation state of the rotor is detected during the first detection operation, the detection sensitivity during the subsequent second detection operation is referred to as the detection sensitivity during the first detection operation. An analog electronic timepiece provided with a detection sensitivity switching means for changing the detection sensitivity. 2. The analog electronic timepiece according to claim 1, wherein the determination of the rotation state of the rotor is performed by converting a current value to a voltage value and determining the magnitude of the voltage value. 3. The detection sensitivity switching means varies the detection sensitivity by first connecting a low-resistance detection resistor to the coil and then switching and connecting a high-resistance detection resistor to the coil. Claim 1 characterized by the following:
Or the analog electronic timepiece according to 2. 4. The detection sensitivity switching means varies the detection sensitivity by first connecting a high Vth detection circuit to the coil and then switchingly connecting a low Vth detection circuit to the coil. Claim 1
Or the analog electronic timepiece according to 2. 5. A step motor comprising a rotor, a stator, and a coil, wherein the rotor is driven based on a current value in the same direction as a drive current induced in the coil by free vibration of the rotor after the end of application of a normal drive pulse. Having a first detection operation for determining and detecting the rotation state of the rotor, and a second detection operation for determining and detecting the rotation state of the rotor based on a current value in a direction opposite to the drive current after the first detection operation. In the electronic timepiece, the detection sensitivity is switched after a lapse of a predetermined period from the end of normal drive pulse application, and when the determination detection state is sensed in the first detection operation, the process proceeds to the second detection operation, An analog electronic timepiece provided with a detection sensitivity switching means for making the detection sensitivity in the second detection operation thereafter different from the detection sensitivity in the first detection operation. . 6. The analog electronic timepiece according to claim 5, wherein the determination of the rotation state of the rotor is performed by converting a current value into a voltage value and determining the magnitude of the voltage value.