clock

Abstract

To prevent positional deviation of hands while reducing power consumption.SOLUTION: A watch comprises: a plurality of hands; a plurality of motors that drive or brake the plurality of hands; a pulse generation unit that supplies, to the plurality of motors, drive pulses for driving the hands and lock pulses for braking the hands; and a control unit that controls operation modes including a normal hand operation mode and a tactile reading mode. When the control unit makes a transition of the operation mode to the tactile reading mode, the pulse generation unit supplies the lock pulses to the motors.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a clock.

Background Art

[0002] Conventionally, a technique has been disclosed that detects an impact on a clock and applies a braking force to the pointer to reduce the displacement of the pointer (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Such a technique for reducing the displacement of the pointer can also be applied to a so-called tactile clock in which the user can directly touch the pointer. However, depending on the reduction ratio of the gear train that rotates the pointer, the holding force of the pointer position may be relatively small. In such a case, when applying the above conventional technique, there is a problem that the braking force when the pointer is touched is insufficient and the pointer is displaced. In addition, since power is consumed to apply a braking force to the pointer, it is preferable that the state of applying the braking force is for a short time.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a clock that can suppress the displacement of the pointer while reducing power consumption.

Means for Solving the Problems

[0006] One embodiment of the present invention includes a plurality of pointers, A dial on which the pointer moves, and a capacitance detection unit that detects the capacitance of the dial,The system comprises: a plurality of motors for driving or braking each of the plurality of pointers; a pulse generating unit that supplies drive pulses for driving the pointers and lock pulses for braking the pointers to the plurality of motors; and a control unit that controls operating modes including a normal needle movement mode and a tactile reading mode. The control unit switches to the tactile reading mode based on the change in capacitance detected by the capacitance detection unit. The pulse generating unit is a clock that supplies the lock pulse to the motor when the control unit switches the operating mode to the tactile reading mode.

[0007] Furthermore, in one embodiment of the present invention, the clock further includes an open / close switch for detecting the opening and closing of the hand cover, and the control unit, upon detection that the cover has been opened by the open / close switch, switches to the tactile reading mode.

[0009] Furthermore, in one embodiment of the present invention, in the clock described above, each of the motors is a two-coil motor comprising a first coil and a second coil, and the lock pulse energizes only the first coil.

[0010] Furthermore, in one embodiment of the present invention, in the clock described above, the control unit stops outputting the lock pulse after it has stopped detecting the electromotive force generated in the second coil by the rotation of the motor rotor during the output of the lock pulse.

[0011] Furthermore, in one embodiment of the present invention, the above-described clock further comprises a needle position detection unit for detecting the indicated position of the pointer, and the operating mode includes a needle position correction mode, and the control unit, after the output of the lock pulse ends, switches to the needle position correction mode and corrects the time based on the detection result of the indicated position by the needle position detection unit.

[0012] Furthermore, one embodiment of the present invention is a clock comprising: a plurality of pointers; a plurality of two-coil motors, each having a first coil and a second coil, which drive or brake each of the plurality of pointers; a pulse generating unit that supplies drive pulses and lock pulses to the plurality of motors for driving the plurality of pointers and for braking the plurality of pointers; and a control unit that controls operating modes including a normal hand movement mode and a tactile reading mode, wherein in the tactile reading mode, in a standby state with the circuit of the first coil open and the circuit of the second coil closed, the control unit excites the second coil with the lock pulse when it detects an electromotive force generated in the second coil by the rotation of the rotor of the motor.

[0013] Furthermore, one embodiment of the present invention is a clock comprising: a plurality of pointers; a plurality of two-coil motors, each having a first coil and a second coil, which drive or brake each of the plurality of pointers; a pulse generating unit that supplies drive pulses and lock pulses to the plurality of motors for driving the plurality of pointers; and a control unit that controls operating modes including a normal hand movement mode and a tactile reading mode, wherein in the tactile reading mode, in a standby state with the circuit of at least one of the first coil or the second coil closed, the control unit, upon detecting an electromotive force generated in the first coil or the second coil by the rotation of the rotor of the motor, energizes only the first coil with the lock pulse.

[0014] Furthermore, in one embodiment of the present invention, the clock described above further comprises a boosting unit for boosting the lock pulse.

[0015] Furthermore, in one embodiment of the present invention, in the clock described above, the control unit stops outputting the lock pulse after it has stopped detecting the electromotive force generated in the second coil by the rotation of the rotor during the output of the lock pulse.

[0016] In addition, in one embodiment of the present invention, the above-described clock further includes a needle position detection unit that detects the indicated position of the pointer. The operation mode includes a needle position correction mode. After the output of the lock pulse ends, the control unit shifts to the needle position correction mode and performs time correction based on the detection result of the indicated position by the needle position detection unit.

Advantages of the Invention

[0017] According to this invention, it is possible to suppress the displacement of the pointer while reducing power consumption.

Brief Description of the Drawings

[0018] [Figure 1] It is an external view of the clock of this embodiment. [Figure 2] It is a view showing the state where the lid of the clock of this embodiment is closed. [Figure 3] It is a view showing the state where the lid of the clock of this embodiment is opened. [Figure 4] It is a view showing an example of the functional configuration of the clock of this embodiment. [Figure 5] It is a view showing an example of the configuration of the motor drive circuit of this embodiment. [Figure 6] It is a view showing an example of the flow of the control operation by the control circuit of this embodiment. [Figure 7] It is a view showing an example of the operation waveforms in the normal running mode and the touch reading mode. [Figure 8] It is a view showing an example of the state of the drive circuit in the standby state of this embodiment. [Figure 9] It is a view showing an example of the state of the drive circuit in the braking state of this embodiment. [Figure 10] It is a view showing a modification example of the detection of the switching to the touch reading mode.

Embodiments for Carrying Out the Invention

[0019] Embodiments of the present invention will be described below with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals, and their descriptions may be omitted.

[0020] Generally, the mechanical part of a watch, including its drive mechanism, is called the "movement." The state in which the dial and hands are attached to this movement and placed inside the case, resulting in a finished product, is called a "complete" watch. In the following explanation, a complete watch or movement will also be referred to simply as a watch.

[0021] Figure 1 is an external view of the clock 1 of this embodiment. As shown in Figure 1, the clock 1 of this embodiment comprises a case body 2, a lid 5, and a case back cover (not shown). Inside the case, which is formed by the case body 2, lid 5, and case back cover, are a movement 3, a dial 4, an hour hand 6, and a minute hand 7. In the following description, the hour hand 6 and minute hand 7 will be collectively referred to as the hands. The clock 1 of this embodiment will be described as a time and minute clock in which the hour hand 6 and minute hand 7 are arranged coaxially and the hour hand 6 and minute hand 7 can be rotated independently. The clock 1 may also be equipped with a crown 8 for manually adjusting the position of the hands.

[0022] Figure 2 shows the clock 1 of this embodiment with the lid 5 closed. Figure 3 shows the clock 1 of this embodiment with the lid 5 open. The clock 1 of this embodiment is a so-called tactile clock that allows the position of the pointer (for example, the time) to be read by touch using a part of the body (for example, a finger).

[0023] The dial 4 has protrusions on its surface indicating the positions from 1 o'clock to 12 o'clock. For example, the dial 4 has large protrusions at the positions of 3 o'clock, 6 o'clock, 9 o'clock and 12 o'clock, and small protrusions at the positions of 1 o'clock, 2 o'clock, 4 o'clock, 5 o'clock, 7 o'clock, 8 o'clock, 10 o'clock and 11 o'clock. The hands move across the surface of the dial 4 as time progresses, with the center of the dial 4 as the center of rotation.

[0024] The cover 5, for example, is equipped with a crystal and functions as a cover for the hands. The cover 5 is openable and closable. In the clock 1 of this embodiment, the user can directly touch the hands by opening the cover 5. The user can read the position of the hands (i.e., the current time) by touching the hands and the protrusions on the dial 4.

[0025] [Watch Functional Configuration] Figure 4 shows an example of the functional configuration of the clock 1 of this embodiment. The functional configuration of the clock 1 will be described with reference to this figure. The clock 1 comprises an oscillation circuit 101, a frequency divider circuit 102, a control circuit 103, a determination circuit 104, a voltage detection circuit 105, a motor drive circuit 106, a boost circuit 107, an open / close detection circuit 108, a memory unit 109, a stepping motor 111, a case body 2, a dial 4, a lid 5, an hour hand 6, and a minute hand 7. Hereafter, the oscillation circuit 101, frequency divider circuit 102, control circuit 103, determination circuit 104, voltage detection circuit 105, motor drive circuit 106, boost circuit 107, switch detection circuit 108, and memory unit 109 will be collectively referred to as the stepping motor control circuit 100. Furthermore, the stepping motor control circuit 100 and the stepping motor 111 will be collectively referred to as the pointer drive unit 110.

[0026] The oscillator circuit 101 generates a signal having a predetermined frequency and outputs the generated signal to the frequency divider circuit 102. The frequency divider circuit 102 divides the signal output by the oscillator circuit 101 to generate a clock signal that serves as the reference for timing, and outputs the generated clock signal to the control circuit 103. The control circuit 103 measures the current time based on the divided clock signal output by the frequency divider circuit 102. Based on the timing result, the control circuit 103 outputs control signals to each part of the clock 1 and controls the operation of each part of the clock 1. The memory unit 109 is equipped with memory elements such as flash ROM and stores information such as the current time measured by the control circuit 103.

[0027] The motor drive circuit 106 receives a control signal from the control circuit 103 and drives the stepping motor 111 based on the received control signal. The stepping motor 111 generates a magnetic field by passing the pulse current output from the motor drive circuit 106 through the drive coil (not shown) of the stator (not shown), causing the rotor (not shown) to rotate. The rotation of the rotor is transmitted to the pointer via the gear train. In other words, the stepping motor 111 is driven by the motor drive circuit 106 and rotates the pointer. The stepping motor 111 includes a first stepping motor 111-1 and a second stepping motor 111-2 (neither of which are shown in the diagram). The first stepping motor 111-1 rotates the hour hand 6. The second stepping motor 111-2 rotates the minute hand 7. The first stepping motor 111-1 and the second stepping motor 111-2 have different gear ratios for the gear trains arranged between the rotor and the pointer, but their other configurations are identical. In the following description, unless otherwise distinguished, the first stepping motor 111-1 and the second stepping motor 111-2 will be collectively referred to as stepping motor 111.

[0028] In other words, clock 1 has multiple hands. Clock 1 also has multiple motors that drive or brake each of the multiple hands.

[0029] The boost circuit 107, based on the control of the control circuit 103, boosts (or does not boost) the voltage supplied from the power source (e.g., a battery not shown) and supplies it to the motor drive circuit 106. The voltage detection circuit 105 detects the induced voltage generated in the drive coil of the stepping motor 111 when the rotor of the stepping motor 111 rotates (or vibrates). The voltage detection circuit 105 outputs the detected induced voltage to the determination circuit 104. The determination circuit 104 determines the rotation state of the rotor of the stepping motor 111 based on the state of the induced voltage detected by the voltage detection circuit 105. For example, the determination circuit 104 determines whether the rotor is rotating (or vibrating) based on whether the voltage value detected by the voltage detection circuit 105 exceeds a predetermined threshold.

[0030] The open / close detection circuit 108 detects the open / closed state of the lid 5. For example, the open / close detection circuit 108 includes a detection switch (open / close switch; not shown) for detecting the open / closed state of the lid 5. The open / close detection circuit 108 outputs the detection result of the detection switch to the control circuit 103. The detection switch may be a mechanical switch that mechanically detects the open / closed state, an electrical switch that detects by opening / closing of electrical contacts or changes in capacitance, or an optical switch that detects optically.

[0031] [Configuration of motor drive circuit 106] Figure 5 shows an example of the configuration of the motor drive circuit 106 in this embodiment. The motor drive circuit 106 comprises a first motor drive circuit 106-1 and a second motor drive circuit 106-2. The first motor drive circuit 106-1 drives the first stepping motor 111-1 to rotate the hour hand 6. The second motor drive circuit 106-2 drives the second stepping motor 111-2 to rotate the minute hand 7. Since the configurations of the first motor drive circuit 106-1 and the second motor drive circuit 106-2 are identical, the first motor drive circuit 106-1 will be described, and the description of the second motor drive circuit 106-2 will be omitted. In addition, in the following description, when the first motor drive circuit 106-1 and the second motor drive circuit 106-2 are not distinguished, they will be collectively referred to as motor drive circuit 106.

[0032] The first stepping motor 111-1 is a two-coil motor having a first drive coil L1 (first coil) and a second drive coil L2 (second coil). The first motor drive circuit 106-1 includes a first drive circuit 106-11 that supplies pulse current to a first drive coil L1, and a second drive circuit 106-12 that supplies pulse current to a second drive coil L2. The first drive coil L1 is connected to output terminals O1 and O2 of the first drive circuit 106-11. The second drive coil L2 is connected to output terminals O3 and O3 of the second drive circuit 106-12.

[0033] The first drive circuit 106-11 is connected to the boost circuit 107. When the control circuit 103 outputs a boost instruction CE (for example, when the boost instruction CE is high H), the boost circuit 107 outputs a voltage VOUT obtained by boosting the power supply voltage VDD. In this case, the first drive circuit 106-11 is supplied with the voltage VOUT boosted by the boost circuit 107. If the boost instruction CE is not output from the control circuit 103 (for example, if the boost instruction CE is low L), the boost circuit 107 outputs voltage VOUT without boosting the power supply voltage VDD (i.e., bypassing the boost circuit). In this case, the power supply voltage VDD is supplied to the first drive circuit 106-11.

[0034] The boost circuit 107 is not connected to the second drive circuit 106-12. The power supply voltage VDD is supplied to the second drive circuit 106-12.

[0035] The first drive circuit 106-11 comprises four switch elements: switch element PTr1, switch element NTr1, switch element PTr2, and switch element NTr2, and constitutes an H bridge that drives the first drive coil L1. The control circuit 103 applies a pulse current to the first drive coil L1 by turning each switch element on or off.

[0036] The second drive circuit 106-12 comprises four switch elements: switch element PTr3, switch element NTr3, switch element PTr4, and switch element NTr4, and constitutes an H-bridge that drives the second drive coil L2. The control circuit 103 provides drive pulses to the second drive coil L2 by turning each switch element on or off.

[0037] The second drive circuit 106-12 comprises a resistor Rs1 and a switch element NTr5, and a resistor Rs2 and a switch element NTr6. One end of the resistor Rs1 is connected to the output terminal O3, and the other end is connected to the switch element NTr5. One end of the resistor Rs2 is connected to the output terminal O4, and the other end is connected to the switch element NTr6. The voltage detection circuit 105 described above detects the induced current flowing through the second drive coil L2 when the rotor of the stepping motor 111 rotates (or vibrates) by the potential difference across the resistor Rs1 or resistor Rs2.

[0038] [Control operation flow] Figure 6 shows an example of the control operation flow by the control circuit 103 of this embodiment. The control circuit 103 (control unit) controls the clock 1 using multiple operating modes. The operating modes include a normal hand movement mode, a tactile reading mode, and a hand position correction mode. The normal hand movement mode is the operating mode in which the hands move in accordance with the passage of time. The tactile mode is an operating mode used when there is a possibility of the user touching the pointer, or when the user is touching the pointer. In one example of this embodiment, the movement of the pointer is stopped in tactile mode. Furthermore, in tactile mode, if the user is touching the pointer, the stepping motor 111 generates a braking force to make it difficult for the pointer's position to change. The needle position correction mode is an operating mode that detects the position of the pointer when the time indicated by the pointer differs from the actual time, and corrects the position of the pointer so that the time indicated by the pointer matches the actual time.

[0039] [Normal needle movement mode] (Step S110) The control circuit 103 drives the pointer in normal hand movement mode. Figure 7 shows examples of operating waveforms in normal needle movement mode and tactile reading mode. In normal needle movement mode, the control circuit 103 does not output the boost instruction CE (for example, the boost instruction CE is set to L). As a result, the first drive circuit 106-11 is supplied with the unboosted power supply voltage VDD. In normal hand movement mode, the pointer is moved by supplying a drive pulse to the first drive coil L1 between timing t1 and timing t2, and by supplying a drive pulse to the second drive coil L2 between timing t2 and timing t3. The figure shows the operating waveform for half a rotation of the rotor of the stepping motor 111. After the rotor has completed half a rotation, drive pulses (not shown) with reversed polarity are sequentially output from the first drive coil L1 and the second drive coil L2. As a result, the rotor completes one full rotation.

[0040] (Step S120) Returning to Figure 6, the control circuit 103 determines whether the lid 5 has been opened or not based on the detection result of the open / close detection circuit 108. If the control circuit 103 determines that the lid 5 has not been opened (Step S120; NO), it returns to step S110. If the control circuit 103 determines that the lid 5 has been opened (Step S120; YES), it proceeds to step S210.

[0041] In other words, the control circuit 103 (control unit) switches to tactile mode when it detects that the lid 5 (cover) has been opened by the detection switch (open / close switch; not shown).

[0042] [Tactile reading mode] (Step S210) The control circuit 103 switches the operating mode from normal needle movement mode to tactile mode. In tactile mode, the control circuit 103 stops the movement of the pointer. More specifically, the control circuit 103 stops the movement of the pointer and stores the time when the pointer movement was stopped in the memory unit 109. With the pointer movement stopped, the control circuit 103 continues to measure the current time.

[0043] As shown in Figure 7, in tactile mode, the control circuit 103 outputs a boost instruction CE (for example, setting the boost instruction CE to H). As a result, the power supply voltage VDD is boosted and supplied to the first drive circuit 106-11. In one example of this embodiment, the boosted voltage VOUT is twice the power supply voltage VDD. For example, if the clock 1 is powered by a battery with a rating of 3V, the power supply voltage VDD is 3V, and the boosted voltage VOUT is 6V.

[0044] In tactile mode, the control circuit 103 controls the stepping motor 111 in two states: standby and braking. In tactile mode, the first drive circuit 106-11 functions as a brake that generates braking torque on the pointer. The second drive circuit 106-12 functions as a detection sensor that detects the movement of the pointer.

[0045] (1) Standby state Figure 8 shows an example of the state of the drive circuit 106 in the standby state of this embodiment. In standby mode, the control circuit 103 turns off all of the switch elements (switch elements PTr1, NTr1, PTr2, and NTr2) of the first drive circuit 106-11. As a result, no voltage VOUT is supplied to the first drive coil L1. The state in which all of the switch elements of the first drive circuit 106-11 are turned off is also called the open standby state. In the open standby state, no braking torque is generated by the first drive coil L1, which reduces power consumption from the power source (e.g., a battery).

[0046] On the other hand, in standby mode, the control circuit 103 causes the second drive circuit 106-12 to function as a detection sensor for detecting the rotation (or vibration) of the rotor. When the rotor rotates (or vibrates), an induced voltage is generated in the second drive coil L2. When a closed circuit including the second drive coil L2 is formed in the second drive circuit 106-12, an induced current IC flows through the second drive circuit 106-12, corresponding to the magnitude of the induced voltage. By passing this induced current IC through a resistive element (resistive element Rs1 or resistive element Rs2) and detecting the potential difference across the resistive element, the rotation (or vibration) of the rotor can be detected. This state in which the induced voltage generated in the second drive coil L2 is detected is also called the sampling standby state.

[0047] More specifically, in standby mode, the control circuit 103 turns off switch element PTr3 and switch element PTr4 among the switch elements of the second drive circuit 106-12. The control circuit 103 turns on the switch element NTr5 and turns off the switch element NTr6. As a result, the resistor element Rs1 is connected to the GND potential. The control circuit 103 repeatedly switches the switch element NTr4 on and off while the switch element NTr3 is turned off. As a result, the voltage detection circuit 105 can detect the induced voltage generated in the second drive coil L2 by detecting the potential difference across the resistive element Rs1.

[0048] Although not shown in the figure, after a predetermined time has elapsed, the control circuit 103 turns off the switch element NTr5 and turns on the switch element NTr6. As a result, the resistor element Rs2 is connected to the GND potential. The control circuit 103 repeatedly switches the switch element NTr3 on and off while the switch element NTr4 is turned off. As a result, the voltage detection circuit 105 can detect the induced voltage generated in the second drive coil L2 by detecting the potential difference across the resistive element Rs2. The voltage detection circuit 105 detects the rotation (or vibration) of the rotor by alternately repeating detection using the resistor element Rs1 and detection using the resistor element Rs2.

[0049] An example of the standby state is shown in Figure 7 from timing t4 to timing t5. Figure 7 shows an example of the induced voltage generated in the second drive coil L2 between timing t4 and timing t5.

[0050] (Step S220) Returning to Figure 6, the control circuit 103 sets the first drive circuit 106-11 to an open standby state and the second drive circuit 106-12 to a sampling standby state. (Step S230) The control circuit 103 determines whether or not the rotor of the stepping motor 111 has rotated (or vibrated) using the second drive circuit 106-12, which is in a sampling standby state.

[0051] As an example, as shown in Figure 7, the determination circuit 104 compares a predetermined determination threshold voltage Vcomp with the magnitude of the induced voltage generated in the second drive coil L2. The determination circuit 104 determines that the rotor is rotating (or vibrating) if the magnitude of the induced voltage generated in the second drive coil L2 exceeds the determination threshold voltage Vcomp. In the example shown in Figure 7, at timing t5, the magnitude of the induced voltage Vrs1 exceeds the determination threshold voltage Vcomp (pulse ta in Figure 7). In this case, the determination circuit 104 determines that the rotor is rotating (or vibrating). On the other hand, the determination circuit 104 determines that the rotor is not rotating (or vibrating) if the magnitude of the induced voltage generated in the second drive coil L2 is less than or equal to the determination threshold voltage Vcomp.

[0052] In this embodiment, it is explained that only the second drive circuit 106-12 has an induced voltage detection function, but the invention is not limited to this. For example, only the first drive circuit 106-11 may have an induced voltage detection function, or both the first drive circuit 106-11 and the second drive circuit 106-12 may have an induced voltage detection function. In other words, in tactile mode, the control circuit 103 (control unit) detects the electromotive force generated in the first drive coil L1 (first coil) or the second drive coil L2 (second coil) by the rotation of the rotor of the stepping motor 111 while in a standby state (waiting state) with at least one of the circuits of the first coil or the second coil closed.

[0053] Returning to Figure 6, if the determination circuit 104 determines that the rotor is rotating (or vibrating) (step S230; YES), the control circuit 103 proceeds to step S240. If the determination circuit 104 determines that the rotor is not rotating (or vibrating) (step S230; NO), the control circuit 103 proceeds to step S260.

[0054] (Step S240) The control circuit 103 puts the drive circuit 106 into a braking state.

[0055] (2) Braking state Figure 9 shows an example of the state of the drive circuit 106 in the braking state of this embodiment. In the braking state, the control circuit 103 turns on switch element PTr1 and switch element NTr2, and turns off switch element NTr1 and switch element PTr2, among the switch elements of the first drive circuit 106-11. As a result, current continues to be supplied to the first drive coil L1 from the power supply, and braking torque is generated. In the braking state, the current supplied to the drive coil by the control of the drive circuit 106 is also called the lock pulse. In the braking state, the state in which the lock pulse is supplied to the drive coil by the control of the drive circuit 106 is also called the locked state. In the braking state, the second drive circuit 106-12 is put into a sampling standby state and continues to detect the rotation (or vibration) of the rotor.

[0056] In other words, the clock 1 includes a drive circuit 106 (pulse generating unit) that supplies drive pulses for driving the pointers and lock pulses for braking the pointers to multiple motors, respectively. The drive circuit 106 (pulse generation unit) supplies a lock pulse to the stepping motor 111 (motor) when the control circuit 103 (control unit) switches the operating mode to the tactile mode. In this context, "when the operating mode is switched to tactile mode" includes both the moment immediately after the operating mode switches to tactile mode and the moment after the operating mode switches to tactile mode and the device enters a braking state.

[0057] As described above, the clock 1 is equipped with a boost circuit 107 (boost unit) that boosts the lock pulse. In tactile mode, the boosted voltage VOUT is supplied to the first drive circuit 106-11. Therefore, the lock pulse supplied by the first drive circuit 106-11 to the first drive coil L1 has a larger current value compared to when an unboosted power supply voltage is supplied. Consequently, the control circuit 103 can brake the rotor more strongly in tactile mode.

[0058] Furthermore, as described above, each stepping motor 111 (motor) is a two-coil motor equipped with a first drive coil L1 (first coil) and a second drive coil L2 (second coil). The lock pulse energizes only the first coil of the two coils. That is, in the braking state, the first drive circuit 106-11 is locked, while the second drive circuit 106-12 is not locked.

[0059] In the braking state, the second drive circuit 106-12 is described as being in a sampling standby state, but this is not limited to this. In the braking state, both the first drive circuit 106-11 and the second drive circuit 106-12 may be in a locked state.

[0060] (Step S250) Returning to Figure 6, the control circuit 103 determines whether or not the rotor of the stepping motor 111 has rotated (or vibrated) using the second drive circuit 106-12, which is in a sampling standby state.

[0061] As an example, as shown in Figure 7, the determination circuit 104 compares a predetermined determination threshold voltage Vcomp with the magnitude of the induced voltage generated in the second drive coil L2. The determination circuit 104 determines that the rotor is rotating (or vibrating) if the magnitude of the induced voltage generated in the second drive coil L2 exceeds the determination threshold voltage Vcomp. In the example shown in Figure 7, at timing t6, the magnitude of the induced voltage Vrs1 exceeds the determination threshold voltage Vcomp (pulse tb in Figure 7). In this case, the determination circuit 104 determines that the rotor has rotated (or vibrated). At timing t8, the magnitude of the induced voltage Vrs1 is less than or equal to the determination threshold voltage Vcomp (pulse tf in Figure 7). In this case, the determination circuit 104 determines that the rotor is not rotating (or vibrating).

[0062] Furthermore, once the determination circuit 104 determines that the rotor has rotated (or vibrated), it continues to determine that the rotor has rotated (or vibrated) for a predetermined time (for example, 1 second), regardless of the magnitude of the induced voltage Vrs1. The determination circuit 104 determines that the rotor is not rotating (or vibrating) if the magnitude of the induced voltage Vrs1 remains below the determination threshold voltage Vcomp for a predetermined period of time (for example, 1 second) or longer (for example, timing t9 in Figure 7).

[0063] Returning to Figure 6, if the determination circuit 104 determines that the rotor is rotating (or vibrating) (step S230; NO), the control circuit 103 returns to step S240 and continues the braking state. If the determination circuit 104 determines that the rotor is not rotating (or vibrating) (step S230; YES), the control circuit 103 releases the braking state and proceeds to step S260.

[0064] In other words, the control circuit 103 (control unit) stops outputting the lock pulse after it stops detecting the electromotive force generated in the second drive coil L2 (second coil) by the rotation of the rotor of the stepping motor 111 (motor) during the output of the lock pulse.

[0065] (Step S260) The control circuit 103 determines whether the lid 5 is closed or not based on the detection result of the open / close detection circuit 108. If the control circuit 103 determines that the lid 5 is not closed (Step S260; NO), it returns to step S220. If the control circuit 103 determines that the lid 5 is closed (Step S260; YES), it proceeds to step S310.

[0066] [Differentiation] In the embodiments described above, the clock switches from the normal hand movement mode to the tactile reading mode when the lid 5 is opened, but this is not the only option. For example, the clock 1 does not need to have a lid 5. In this case, the clock 1 may switch from the normal hand movement mode to the tactile reading mode when the user's finger approaches (or touches) the dial 4.

[0067] Figure 10 shows a modified example of the detection of switching to tactile mode. In this modified example, the control circuit 103 includes a detection voltage supply terminal 1031 and a capacitance detection terminal 1032. A detection resistor R is connected between the detection voltage supply terminal 1031 and the capacitance detection terminal 1032. The capacitance detection terminal 1032 is connected to the character plate 4 and detects changes in capacitance between the character plate 4 and the GND potential. For example, when the user's finger is not touching the character plate 4, the capacitance between the character plate 4 and the GND potential is capacitance Ca. If the capacitance between the user's finger and the GND potential is capacitance Cb, then when the user's finger approaches (or touches) the character plate 4, the capacitance between the character plate 4 and the GND potential becomes capacitance Ca + capacitance Cb. By detecting this change in capacitance, the control circuit 103 can determine whether or not the user's finger has approached (or touched) the character plate 4. In this modified example, the control circuit 103 switches from the normal hand movement mode to the tactile reading mode when it determines that the user's finger has approached (or touched) the dial 4. In other words, the control circuit 103 functions as a capacitance detection unit that detects the capacitance of the dial 4. Based on the change in capacitance detected by the capacitance detection unit, the control circuit 103 switches to tactile reading mode.

[0068] [Needle position correction mode] In tactile mode, the control circuit 103 stops the movement of the pointer. Therefore, when tactile mode ends, the position of the pointer (i.e., the time indicated by the pointer on the dial 4) may differ from the actual time. When tactile mode ends, the control circuit 103 switches its operating mode to the pointer position correction mode and corrects the position of the pointer to the actual time.

[0069] (Step S310) Returning to Figure 6, the control circuit 103 switches the operating mode from tactile mode to needle position correction mode. In needle position correction mode, there are two methods for correcting the position of the pointer performed by the control circuit 103: one based on the stored pointer position and one based on the detected pointer position.

[0070] (1) Correction based on the position of the memorized pointer The control circuit 103 reads from the memory unit 109 the time stored in the memory unit 109 in step S210 (i.e., the time when the pointer movement was stopped). The control circuit 103 calculates the difference between the time read from the memory unit 109 and the current time during timing. The control circuit 103 corrects the position of the pointer by outputting a drive pulse corresponding to the calculated difference from the drive circuit 106. As a result, the position of the pointer matches the current time.

[0071] (2) Correction based on the location of the detected indicator The control circuit 103 detects the position of the pointer. Known methods such as position detection based on torque changes of the load gear or optical position detection using a photosensor are used to detect the position of the pointer. In the position detection method using load gears, a load gear is provided in part of the gear train (or a gear that rotates outside the gear train in conjunction with the rotor's rotation) that has load teeth with a different rotational load than the other teeth. The position of the pointer is detected based on the positional relationship between the position where the torque change due to the load teeth occurs and the position of the pointer. In the position detection method using a photosensor, a detection gear is provided in part of the gear train (or a gear that rotates outside the gear train in conjunction with the rotor's rotation) whose optical properties differ from other parts depending on its rotational position (for example, a light-transmitting hole is drilled at a predetermined position). The position of the pointer is detected based on the positional relationship between the position where the change in optical properties occurs and the position of the pointer. Furthermore, the method for detecting the position of the pointer is not limited to this.

[0072] In other words, the clock 1 further includes a hand position detection unit such as a load gear or a photosensor that detects the indicated position of the hands. The operating modes include a hand position correction mode, and the control circuit 103 (control unit) switches to the hand position correction mode after the output of the lock pulse ends and corrects the time based on the detection result of the indicated position of the hands by the hand position detection unit.

[0073] In tactile mode, if the user touches the pointer and a force greater than the braking torque in the locked state is applied to the pointer, the position of the pointer may change. In this case, the pointer will show a time different from the time stored in the memory unit 109 in step S210 (i.e., the time when the pointer's movement was stopped). Even in such a case, the control circuit 103 can correct the position of the pointer to show the current time.

[0074] As described above, the clock 1 of this embodiment supplies a lock pulse to the stepping motor 111 when it switches to tactile mode. With the clock 1 of this embodiment configured in this way, since the lock pulse is supplied only in tactile mode, it is possible to apply braking force to the pointer while reducing power consumption.

[0075] Furthermore, tactile watches are generally prone to misalignment of the hands due to the user touching them. Therefore, it is desirable to have a time correction function that automatically adjusts the hands to the actual time. When performing a time correction function, the position of the hands is detected. If this position detection is performed by changing the load or optical characteristics of the gears as described above, adopting an independent hour and minute gearbox that drives the hour and minute hands with separate motors can improve the accuracy of position detection and allow for quick alignment of the hands. On the other hand, an independent hour and minute gearbox has a relatively smaller gear ratio (reduction ratio) compared to a so-called two-hand gear train. Therefore, when an independent hour and minute gearbox is adopted, the holding force (holding torque) that maintains the position of the hands is relatively small, making the hands more prone to misalignment. The clock 1 of this embodiment employs an independent gearbox for the hour and minute hands, and by providing a lock pulse in tactile mode, it is possible to improve the accuracy of position detection, enabling quick alignment of the hands and reducing misalignment of the hands.

[0076] Furthermore, the clock 1 of this embodiment detects when the lid 5 (cover) is opened and switches to tactile mode, so it can switch to tactile mode before the user touches the hands. Furthermore, as described above, the clock 1 of this embodiment may also be equipped with a capacitance detection unit that detects the capacitance of the dial 4. In this case, even if the clock 1 is not equipped with a lid 5 (cover), it can detect the user's attempt to touch the hands and switch to tactile mode before the user touches the hands.

[0077] Furthermore, the clock 1 of this embodiment detects the rotation (or vibration) of the rotor while the lock pulse is being output. With the clock 1 configured in this way, if the rotor stops rotating (or vibrating) while the lock pulse is being output, the lock pulse can be stopped immediately. Therefore, the clock 1 of this embodiment can prevent the lock pulse from continuing unnecessarily, thereby reducing power consumption.

[0078] Furthermore, the clock 1 of this embodiment is equipped with a boost circuit that increases the voltage of the lock pulse. With the clock 1 configured in this way, the braking force of the pointer can be further increased, and the misalignment of the pointer can be further reduced.

[0079] Although embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications can be made as appropriate without departing from the spirit of the present invention. The configurations described in each of the above embodiments may also be combined.

[0080] Furthermore, each component of the device in the above embodiment may be implemented by dedicated hardware, or it may be implemented by memory and a microprocessor.

[0081] Furthermore, each component of each device may consist of memory and a CPU (Central Processing Unit), and its functions may be realized by loading a program into memory and executing it to realize the functions of each component of each device.

[0082] Alternatively, programs for realizing the functions of each part of each device may be recorded on a computer-readable recording medium, and the programs recorded on this recording medium may be loaded into a computer system and executed to perform processing by the parts of the control unit. The term "computer system" here includes hardware such as the operating system and peripheral devices.

[0083] Furthermore, "computer system" shall also include the homepage provisioning environment (or display environment) if a WWW system is being used. Furthermore, "computer-readable recording media" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. In addition, "computer-readable recording media" also includes those that dynamically hold programs for a short period of time, such as communication lines used when transmitting programs over networks such as the Internet or communication lines such as telephone lines, and those that hold programs for a certain period of time, such as volatile memory inside computer systems that act as servers or clients in such cases. Moreover, the above-mentioned programs may be for the purpose of realizing some of the functions described above, and may also be able to realize the above-mentioned functions in combination with programs already recorded in the computer system. [Explanation of symbols]

[0084] 1...Watch, 2...Case body, 3...Movement, 4...Dial, 5...Lid, 6...Hour hand, 7...Minute hand, 100...Stepping motor control circuit, 101...Oscillation circuit, 102...Frequency divider circuit, 103...Control circuit, 104...Determination circuit, 105...Voltage detection circuit, 106...Motor drive circuit, 107...Boost circuit, 108...Open / close detection circuit, 109...Memory unit, 110...Pointer drive unit, 111...Stepping motor

Claims

1. Multiple guidelines, A dial on which the pointer moves, A capacitance detection unit for detecting the capacitance of the dial, Multiple motors for driving or braking each of the multiple pointers, A pulse generating unit that supplies drive pulses for driving the pointer and lock pulses for braking the pointer to the plurality of motors, A control unit that controls the operating modes, including a normal needle movement mode and a tactile reading mode, Equipped with, The control unit switches to the tactile reading mode based on the change in capacitance detected by the capacitance detection unit. The pulse generating unit supplies the lock pulse to the motor when the control unit switches the operating mode to the tactile reading mode. clock.

2. Open / close switch for detecting the opening and closing of the cover of the aforementioned indicator Furthermore, The control unit, upon detecting that the cover has been opened by the opening / closing switch, switches to the tactile reading mode. The clock according to claim 1.

3. Each of the aforementioned motors is a two-coil motor comprising a first coil and a second coil, The lock pulse energizes only the first coil. The clock according to claim 1.

4. The control unit stops outputting the lock pulse after it stops detecting the electromotive force generated in the second coil by the rotation of the motor rotor during the output of the lock pulse. The clock according to claim 3.

5. Needle position detection unit for detecting the indicated position of the pointer Furthermore, The operating modes include a needle position correction mode. After the output of the lock pulse ends, the control unit switches to the needle position correction mode and corrects the time based on the detection result of the indicated position by the needle position detection unit. The clock according to claim 4.

6. Multiple guidelines, A two-coil motor, each having a first coil and a second coil, comprising a plurality of motors for driving or braking each of the plurality of pointers, A pulse generating unit supplies drive pulses for driving the plurality of pointers and lock pulses for braking the plurality of pointers to the plurality of motors, A control unit that controls the operating modes, including a normal needle movement mode and a tactile reading mode, Equipped with, In the tactile mode, the control unit, in a standby state with the circuit of the first coil open and the circuit of the second coil closed, detects the electromotive force generated in the second coil by the rotation of the motor rotor and energizes it with the lock pulse. clock.

7. Multiple guidelines, A two-coil motor, each having a first coil and a second coil, comprising a plurality of motors for driving or braking each of the plurality of pointers, A pulse generating unit supplies drive pulses for driving the plurality of pointers and lock pulses for braking the plurality of pointers to the plurality of motors, A control unit that controls the operating modes, including a normal needle movement mode and a tactile reading mode, Equipped with, In the tactile mode, when the control unit detects an electromotive force generated in the first coil or the second coil by the rotation of the motor rotor while in a standby state with at least one of the circuits of the first coil or the second coil closed, it energizes only the first coil with the lock pulse. clock.

8. Booster section for boosting the lock pulse Furthermore, The clock according to claim 7.

9. The control unit stops outputting the lock pulse after it stops detecting the electromotive force generated in the second coil by the rotation of the rotor during the output of the lock pulse. The clock according to claim 7 or 8.

10. Needle position detection unit for detecting the indicated position of the pointer Furthermore, The operating modes include a needle position correction mode. After the output of the lock pulse ends, the control unit switches to the needle position correction mode and corrects the time based on the detection result of the indicated position by the needle position detection unit. The clock according to claim 9.

Images