JPH0729512Y2 - Analog electronic clock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement of a rotation detection method for a step motor of an analog electronic timepiece.

[Prior Art] In a conventional analog electronic timepiece, as disclosed in Japanese Examined Patent Publication (Kokoku) No. 57-18440, rotation is performed after a preset non-detection period of several msec after application of a drive pulse in order to avoid erroneous detection. A detection section was provided.

[Problems to be solved by the invention] However, in the above-mentioned conventional method, since the non-detection section for avoiding erroneous detection is preset for each model, the change in the rotation speed of the rotor due to deterioration of the lubricating oil, In some cases, the change in the drive pulse width as disclosed in JP-A-61-15385 and the variation in individual movements cannot be dealt with, resulting in erroneous detection.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide an analog electronic timepiece with low current consumption and high reliability by accurately detecting the rotation of a rotor.

[Means for Solving the Problems] In order to solve the above problems, the present invention has a step motor including a rotor, a stator, and a coil, and generates a current induced in the coil by free vibration of the rotor after applying a drive pulse. In an analog electronic timepiece that converts into a voltage value and detects the rotation of the rotor based on the magnitude of the voltage value, a current flowing in the same direction as the drive current among the induced currents is the same direction current,
When a current flowing in the reverse direction is called a reverse current, it has a first detecting means for detecting the same direction current and a second detecting means for detecting the reverse current, and the first detecting means detects the same direction current. After the detection, the second detecting means is operated to detect the reverse current.

[Operation] According to the above configuration of the present invention, since the non-detection section for avoiding erroneous detection is automatically set by the first detection means, the rotation of the rotor is accurately detected by the second detection means. be able to.

[Embodiment] Hereinafter, the present invention will be described in detail based on an embodiment.

FIG. 1 is a block diagram showing a configuration example of an analog electronic timepiece according to this embodiment. Hereinafter, FIG. 1 will be described.

Reference numeral 1 is a crystal oscillator circuit.
It is oscillating at 768Hz.

2 is a frequency dividing circuit, which is output from the crystal oscillating circuit 3 32
The 768 Hz signal φ32K is sequentially divided to form a frequency signal necessary for the motor drive signal forming circuit 6 and the like.

3 is a 1/8 up / down counter, and the output data (α, β, γ) is increased by the correction drive pulse P2 output from the motor drive signal forming circuit 4 and the 1/80 Hz signal output from the frequency dividing circuit 2 Down by φ1 / 80.

Reference numeral 4 denotes a motor drive signal forming circuit, which is the normal drive pulse P1 and the correction drive pulse shown in the timing chart of FIG.
P2, the first chopper amplification pulse SP1, the second chopper amplification pulse SP2, and a polarity storage signal Pol (not shown) for storing the output direction of each pulse are formed and output for each hand movement cycle. The normal drive pulse P1 is 2.20msec ~
Eight types are prepared in steps of 0.24 msec up to 3.91 msec. A wider pulse is output as the data value of the 1/8 up / down counter 3 increases, so that the step motor is always driven with the optimum pulse width. It is configured. Further, the hand movement cycle of this embodiment is 1 second.

FIG. 3 shows a specific configuration example of the first chopper amplification pulse SP1 and the second chopper amplification pulse SP2, and FIG. 4 shows a timing chart thereof. In FIG. 3, 301,307,30
8 is a NOT gate, 302, 306, 309, 310 are AND gates, 303, 304 are flip-flops (FF) that transfer the data input to the D terminal to the Q and XQ terminals at the rising edge of the clock pulse input to the C terminal, and 305 is It is a NOR gate. FF304 is for defining the start of SP1 output, and prevents SP1 from being output for 3.9 msec after P1 starts to be output. FF303 is for defining the output section of SP2, and 23.4msec after P1 starts to be output.
After that, SP2 is not output. Also, SP1
The AND gate 309 outputs the first detection signal DE1 output from the motor driver and the detection circuit 6 only when SP1 is low, and the SP2 is the first detection signal output from the motor driver and the detection circuit 6 by the AND gate 310. It is output only when DE1 is High and the second detection signal DE2 is Low.

An output decoder 5 is a motor drive signal forming circuit 4
Each pulse of P1, P2, SP1, and SP2 output from is decoded and output to the signals a1 to a6 shown in the timing chart of FIG. The correction drive pulse P2 is output only when the rotation detection determines that the rotation is not performed (when the second detection signal DE2 is Low).

Reference numeral 6 denotes a motor driver and a detection circuit, which is a P-channel type which constitutes a motor driver as shown in FIG.
MOS transistors 601 and 603, N-channel MOS transistors 602 and 604, chopper amplification resistors 605 and 606, P-channel MOS transistors 607 and 608 for switching the chopper amplification resistors, and detection voltage generated during chopper amplification are power supplies. Comparators 609 and 610, NOT gates 612 and 61 that output goes High when the voltage is exceeded
3, AND gates 614, 615, 616 and 617, OR gates 618 and 61
9. SR latches 620 and 621 that are set by the signal input to the S terminal and reset by the signal input to the R terminal
Drive pulses P1 and P2 for driving the step motor included in the display mechanism 8 are supplied to the O1 and O2 terminals, and the detection voltage generated at the coil end when the chopper amplification pulse is output is the power supply voltage. High above
And outputs a first detection signal DE1 and a second detection signal DE2. The polarity memory signal Pol and the gates of 612 to 619 detect the detection voltage DE1 generated at the coil end on the side opposite to the drive pulse applied side and the detection voltage generated at the coil end on the side where the drive pulse is applied. DE2 is set to High. In addition, the side comparator 60 not shown
9 and 610 are configured to operate only on detection.

Reference numeral 6 denotes a display mechanism, which includes a step motor including a rotor, a stator, and a coil, a train wheel mechanism connected to the rotor for moving a time display hand, a time display hour hand, and a minute hand.

FIG. 7 shows an example of the waveform of the current flowing through the coil when the drive pulse is applied. In FIG. 7, a portion T1 is a current flowing through the coil by the application of the drive pulse, and a portion T2 is a current induced in the coil by the free vibration of the rotor after the application of the drive pulse. The analog electronic timepiece according to the present embodiment detects the induced current in the same direction as the current flowing through the coil during the drive pulse application (8 in FIG. 7) by the first chopper amplification pulse SP1 (first detection). Signal DE1 is High
Second), the second chopper amplification pulse SP2 for detecting the induced current (the portion 9 in FIG. 7) in the opposite direction to the current flowing through the coil during the application of the drive pulse is output to detect the rotation of the rotor. Is configured. Therefore, as shown in FIG. 8, even if the rotation speed of the rotor changes or the drive pulse width changes due to deterioration of the lubricating oil or the like, and the timing at which part 8 in FIG. 7 appears changes, Since the non-detection section is automatically set by the detection signal DE1,
With the second chopper amplification pulse SP2, the magnitude of the reverse current in the portion 9 in FIG. 7 can be reliably detected, and it can be accurately determined whether or not the rotor has rotated.

[Effects of the Invention] As described in detail with reference to the embodiments above, the analog electronic timepiece of the present invention includes the first detection means for detecting the induced current in the same direction as the driving current and the induced current in the opposite direction to the driving current. Since it has the second detecting means for detecting, the first detecting means automatically sets the non-detection section for preventing erroneous detection, and the second detecting means determines whether the rotor has rotated. Can be accurately determined. Therefore, it is possible to provide an analog electronic timepiece which can easily cope with the deterioration of the lubricating oil and the change of the pulse width, has high reliability, and can be maintained free, and which has a low current consumption.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a timing chart of signals formed by the motor drive signal forming circuit 4 of FIG. FIG. 3 is a circuit diagram showing a specific configuration example of SP1 and SP2. FIG. 4 is a timing chart of FIG. FIG. 5 is a timing chart of signals formed by the output decoder 5 of FIG. FIG. 6 is a circuit diagram showing a specific configuration example of the motor driver and detection circuit 6 of FIG. FIG. 7 is a current waveform diagram when a drive pulse is applied to the coil. FIG. 8 is a current waveform diagram when a drive pulse is applied to the coil when the lubricating oil deteriorates. 1 ... Oscillation circuit 2 ... Dividing circuit 3 ... Up-down counter 4 ... Motor drive signal forming circuit 5 ... Output decoder 6 ... Motor driver and detection circuit 7 ... Display mechanism

Claims (1)

[Scope of utility model registration request] 1. A step motor comprising a rotor, a stator, and a coil, wherein after a drive pulse is output, a current induced in the coil by free vibration of the rotor is converted into a voltage value, and the rotation of the rotor is detected by the magnitude of the voltage value. In the analog electronic timepiece, when a current flowing in the same direction as the driving current among the induced currents is called a same-direction current and a current flowing in the opposite direction is called a reverse-direction current, it is opposite to the first detecting means for detecting the same-direction current. A second detection means for detecting the directional current,
The analog electronic timepiece is characterized in that the second detecting means is operated to detect the reverse current after the same detecting current is detected by the detecting means.