Electronic clock

Abstract

To provide an electronic clock which can move hour and minute hands functioning as chronograph hour hand and chronograph minute hand, to a measurement start position in short time, when being switched to a chronograph mode.SOLUTION: An electronic clock comprises: a first operation part for performing a mode switching operation of switching between a time display mode and a chronograph mode; a first pointer for displaying hours of time using a 12-hour system in the time display mode, and for displaying hours of measurement time in the chronograph mode; and a display control part for moving the first pointer by rapid feed to a measurement start position in the chronograph mode, on the basis of the mode switching operation for switching to the chronograph mode. The display control part distinguishes and manages each indication position of 0 o'clock and 12 o'clock, and at switching time to the chronograph mode, an indication position with shorter moving time of the first pointer from two indication positions is set to the measurement start position, on the basis of display time of the first pointer at the switching operation time, and then, the first pointer is moved to the set measurement start position.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electronic timepiece. [Background technology]

[0002] Patent Document 1 discloses an electronic timepiece that has a subdial that indicates the time in a selected time zone, separate from the hour and minute hands that indicate the local time. The subdial of this electronic timepiece is a 24-hour clock with a minute hand that makes one rotation per hour and an hour hand that makes one rotation per 24 rotations of the minute hand, i.e., one rotation per 24 hours, and is driven by a single motor.

[0003] The electronic timepiece of Patent Document 1 has a chronograph mode in addition to a time display mode. In the chronograph mode, the subdial functions as a chronograph minute hand and a chronograph hour hand. Therefore, when the chronograph mode is switched to by a user's operation, the hour and minute hands of the subdial move in the faster direction of rotation, either clockwise or counterclockwise, from the position of the hands immediately before switching to the chronograph mode to the reset-to-zero position indicating 0:00. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-200502 Summary of the Invention [Problem to be solved by the invention]

[0005] The electronic timepiece has a problem in that when switched to chronograph mode, it takes a maximum of 12 hours for the hour hand of the subdial to move to the zero-reset position, which takes a long time to complete. For this reason, there is a demand for an electronic timepiece that can move the pointer that functions as the chronograph hour hand to the zero-reset position in a short time when switched to chronograph mode. [Means for solving the problem]

[0006] The electronic watch disclosed herein is an electronic watch having at least two modes, a time display mode and a chronograph mode, and is equipped with a first operating unit for performing a mode switching operation to switch between the modes, a first hand that displays the time in a 12-hour format in the time display mode and displays the measured time in the chronograph mode, and a display control unit that moves the first hand quickly forward to the measurement start position in the chronograph mode based on the mode switching operation to switch to the chronograph mode, and is characterized in that the display control unit distinguishes and manages two indication positions of the first hand in the time display mode: a first indication position where the first hand indicates midnight and a second indication position where the first hand indicates 12 o'clock, and when switching to the chronograph mode, sets the indication position of the two indication positions which the first hand moves to the shorter time as the measurement start position based on the displayed time of the first hand at the time of the switching operation, and moves the first hand to the set measurement start position. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a front view showing an electronic timepiece according to an embodiment. [Figure 2] FIG. 2 is a plan view showing the main parts of the movement of the electronic timepiece according to the embodiment. [Figure 3] FIG. 2 is a plan view showing the main parts of the movement of the electronic timepiece according to the embodiment. [Figure 4] FIG. 1 is a block diagram showing the configuration of an electronic timepiece according to an embodiment. [Figure 5] 10 is a flowchart showing a process of switching to a chronograph mode in the embodiment. [Figure 6] 10 is a flowchart showing a process performed during a split operation according to an embodiment. [Figure 7] 10 is a flowchart illustrating a process after releasing a split according to an embodiment. [Figure 8] 10 is a flowchart illustrating a process for switching to a time display mode according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The electronic timepiece 1 of this embodiment will be described below with reference to the drawings. As shown in Figure 1, the electronic timepiece 1 comprises an exterior case 2, a crown 3 for external operation, and two buttons 4A and 4B. As will be described later, the exterior case 2 houses a dial 5, a movement 10, and other components. The crown 3 is located at the 3 o'clock position of the dial 5 in a plan view, and the buttons 4A and 4B are located at the 2 o'clock and 4 o'clock positions, respectively. The electronic watch 1 has a display unit 40 that displays the time, etc., and includes center hands 6 consisting of an hour hand 61, a minute hand 62, and a second hand 63, a first small hand 71, a second small hand 72, a third small hand 73, and a fourth small hand 74, and a date wheel 50.

[0009] A central through-hole (not shown) that passes through the dial 5 is formed in the center of the plane of the dial 5, and a center hand shaft 60 to which the center hand 6 is attached is disposed in the central through-hole. The dial 5 has three small windows (subdials). That is, as shown in FIG. 1 , the dial 5 has a circular first small window 71A and a first small hand 71 at the 6 o'clock position relative to the planar center where the center hand axis 60 is provided, a circular second small window 72A and a second small hand 72 at the 9 o'clock position, and a circular third small window 73A and a third small hand 73 at the 12 o'clock position. A rectangular date window 51 is provided between 4 o'clock and 5 o'clock (at the 4.5 o'clock position) relative to the planar center of the dial 5. A date wheel 50, which is a calendar wheel, is located on the back side of the dial 5, and the date wheel 50 can be seen through the date window 51. Between the planar center of the dial 5 and the date window 51, a circular fourth small window 74A and a fourth small hand 74 are provided. For this reason, in addition to a central through-hole formed in the center of the plane through which the center hand axis 60 is inserted, the dial 5 is also formed with four through-holes (not shown) through which the small hand axes of the first small hand 71, second small hand 72, third small hand 73, and fourth small hand 74 are inserted, as well as a date window 51.

[0010] The electronic timepiece 1 is configured to be able to select a chronograph mode that executes a stopwatch function in addition to a time display mode. In the chronograph mode, some of the hands function as chronograph hands. The hour hand 61 and minute hand 62 display the local time hours and minutes in both the time display mode and the chronograph mode. The second hand 63 displays the local time seconds in the time display mode, and functions as a second chronograph hand, or second CG hand, in the chronograph mode. In the time display mode, the first small hand 71 is a home time hand that indicates the time in a time zone preset by the user, and is composed of a small hour hand 711 and a small minute hand 712 that operate in conjunction with one motor. In the chronograph mode, the small hour hand 711 and the small minute hand 712 function as hour chronograph hands and minute chronograph hands, that is, hour and minute CG hands. The small hour hand 711 is a 12-hour hand that makes one rotation in 12 hours. Therefore, in this embodiment, the small hour hand 711 is the first hand, and the small minute hand 712 is the second hand. The second hand 63, which functions as the second CG hand in the chronograph mode, is the fourth hand that displays measured times below the second.

[0011] The second small hand 72 is a mode hand that indicates various information. While the information indicated by the second small hand 72 can be set as appropriate, in this embodiment, it functions as a mode hand that indicates two modes: time display mode and chronograph mode. Specifically, in time display mode, the second small hand 72 functions as a day hand that indicates the day of the week, and as a power indicator that indicates low battery power when the battery level is low. The remaining battery power is also displayed when a specific button is pressed. When the watch is switched to chronograph mode, the second small hand 72 points to a scale indicating chronograph mode, such as the letters "CHR." If the electronic timepiece 1 has the ability to receive GPS satellite signals, the second small hand 72 may also indicate the setting of each mode, such as airplane mode, which prohibits reception; timekeeping mode, which receives GPS time information and adjusts the internal time; and positioning mode, which receives GPS time information and orbit information and adjusts the internal time and time zone, in addition to the above functions, or may be used to set daylight saving time. The third small hand 73 is a 1 / 20 second chronograph hand, or 1 / 20 second CG hand, which moves only in the chronograph mode and stops at the 0 second position in the time display mode. This third small hand 73 is a fourth pointer, like the second hand 63, because it displays times measured below the second, or 1 / 20 second, in the chronograph mode. The fourth small hand 74 is an AM / PM hand that indicates whether the home time indicated by the first small hand 71 is in the morning or afternoon. In the chronograph mode, the fourth small hand 74 moves in conjunction with the first small hand 71, but does not have any particular role.

[0012] The display parts, namely, hour hand 61, minute hand 62, second hand 63, first small hand 71 (small hour hand 711, small minute hand 712), second small hand 72, third small hand 73, and date wheel 50, are driven via a motor and train wheel, which will be described later. The fourth small hand 74 is not driven by an independent motor, but is driven in conjunction with the small hour hand 711 of the first small hand 71 by the motor and train wheel that drive the first small hand 71, and is a 24-hour hand that makes one rotation in 24 hours. Therefore, the fourth small hand 74 operates in conjunction with the small hour hand 711, which is the first hand, and is a third hand that makes one rotation in 24 hours.

[0013] The main parts of the movement 10 housed in the exterior case 2 of the electronic timepiece 1 will be described with reference to Figures 2 and 3. Figure 2 is a plan view of the main parts of the movement 10 seen from the back cover side, and Figure 3 is a plan view of the main parts of the movement 10 seen from the dial 5 side. As shown in Figures 2 and 3, the movement 10 includes a main plate 15, a drive mechanism 100 supported by the main plate 15, and a secondary battery 14. The main plate 15 is made of a non-conductive material such as plastic. On the back cover side of the main plate 15, multiple motors and gear trains that make up the drive mechanism 100 are arranged.

[0014] 2 and 3, the drive mechanism 100 has a first motor 101 and a first train wheel 110 that drive the hour hand 61, a second motor 102 and a second train wheel 120 that drive the minute hand 62, and a third motor 103 and a third train wheel 130 that drive the second hand 63. The drive mechanism 100 also has a fourth motor 104 and a fourth train wheel 140 that drive the small hour hand 711 (first small hand 71), the small minute hand 712, and the fourth small hand 74, a fifth motor 105 and a fifth train wheel 150 that drive the second small hand 72, a sixth motor 106 and a sixth train wheel 160 that drive the third small hand 73, and a seventh motor 107 and a seventh train wheel 170 that drive the date indicator 50. Each of the motors 101 to 107 is a step motor for a timepiece, and only the fourth motor 104 is a two-coil step motor having two coils. Each wheel train is supported by a main plate 15 and a wheel train bridge (not shown).

[0015] The first wheel train 110 includes a first intermediate hour wheel 111 that meshes with the rotor pinion of the first motor 101, a second intermediate hour wheel 112 that meshes with the pinion of the first intermediate hour wheel 111, a third intermediate hour wheel 113 that meshes with the pinion of the second intermediate hour wheel 112, and an hour detection wheel 114 and an hour wheel 115 that mesh with the pinion of the third intermediate hour wheel 113. As shown in Figure 3, the hour detection wheel 114 and the hour wheel 115 are arranged on the front side of the main plate 15, i.e., on the dial 5 side. The hour hand 61 is attached to a cylindrical hour hand stem 610 of the hour wheel 115. The first hour intermediate wheel 111, the second hour intermediate wheel 112, and the hour detection wheel 114 are formed with holes for detecting hand positions that are detected by a conventional hand position detection device equipped with a light-emitting unit and a light-receiving unit.

[0016] The second wheel train 120 includes a fifth wheel & pinion 121 that meshes with the rotor pinion of the second motor 102, a third wheel & pinion 122 that meshes with the pinion of the fifth wheel & pinion 121, and a center wheel & pinion 123 that meshes with the pinion of the third wheel & pinion 122. The center wheel & pinion 123 is arranged to overlap with the hour wheel 115 in a plan view. The minute hand 62 is attached to a cylindrical minute hand shaft 620 of the center wheel & pinion 123. The fifth wheel & pinion 121, the third wheel & pinion 122, and the center wheel & pinion 123 have holes formed therein for detecting hand positions that are detected by a hand position detecting device.

[0017] The third wheel train 130 is equipped with an intermediate second wheel 131 that meshes with the rotor pinion of the third motor 103, a second wheel 132 that meshes with the pinion of the intermediate second wheel 131, and a second detection wheel 133 that meshes with the pinion of the intermediate second wheel 131. The second wheel 132 is arranged to overlap the center wheel & pinion 123 and the hour wheel 115 in a plan view. A second hand 63 is attached to a second hand shaft 630 of the second wheel 132. The intermediate second wheel 131 and the second detection wheel 133 are formed with holes for hand position detection that are detected by a hand position detection device. 3, the minute hand shaft 620 is disposed within the cylindrical hour hand shaft 610, and the second hand shaft 630 is disposed within the cylindrical minute hand shaft 620, these constituting the center hand shaft 60. The hour wheel 115 on which the hour hand shaft 610 is provided, the center wheel & pinion 123 on which the minute hand shaft 620 is provided, and the second wheel 132 on which the second hand shaft 630 is provided constitute the center hand wheel.

[0018] The fourth train wheel 140 is a train wheel that drives the small hour hand 711 and small minute hand 712 of the first small hand 71, and is equipped with an HT intermediate wheel 141 that meshes with the rotor pinion of the fourth motor 104, an HT minute wheel 142 that meshes with the pinion of the HT intermediate wheel 141, an HT minute wheel 143 that meshes with the pinion of the HT minute wheel 142, and an HT hour wheel 144 that meshes with the pinion of the HT minute wheel 143. The HT hour wheel 144 overlaps with the HT minute wheel 142 in a plan view, and is arranged on the front side of the main plate 15, as shown in FIG. The first small hand 71 is attached to a first small hand shaft 710 provided in the fourth train wheel 140. Specifically, the small hour hand 711 is attached to an HT hour hand shaft 713 provided in the HT hour wheel 144, and the small minute hand 712 is attached to an HT minute hand shaft 714 provided in the HT minute wheel 142. Therefore, the first small hand shaft 710 is made up of the HT hour hand shaft 713 and the HT minute hand shaft 714, and the HT hour wheel 144 and the HT minute wheel 142 form the first small hand wheel.

[0019] The fourth train wheel 140 further has a train wheel provided on the surface side of the main plate 15 in order to drive the fourth small hand 74, which is the AM / PM hand (24-hour hand). That is, as shown in Fig. 3, the fourth train wheel 140 is provided with a 24-hour hand first intermediate wheel 145 that meshes with the HT hour wheel 144, a 24-hour hand second intermediate wheel 146 that meshes with the 24-hour hand first intermediate wheel 145, a 24-hour hand third intermediate wheel 147 that meshes with the 24-hour hand second intermediate wheel 146, and a 24-hour hand wheel 148 that meshes with the pinion of the 24-hour hand third intermediate wheel 147. A fourth small hand 74 is attached to the 24-hour hand shaft 740 of the 24-hour hand wheel 148.

[0020] The fifth train wheel 150 is a train wheel that drives the second small hand 72, and as shown in Fig. 2, is provided with a first intermediate wheel 151 that meshes with the rotor pinion of the fifth motor 105, and a second small hand wheel 152 that meshes with the pinion of the first intermediate wheel 151. As shown in Fig. 3, the second small hand wheel 152 has a second small hand shaft 720 to which the second small hand 72 is attached.

[0021] The sixth wheel train 160 is a wheel train that drives the third small hand 73, and as shown in Figure 2, is equipped with a first intermediate wheel 161 that meshes with the rotor pinion of the sixth motor 106, and a third small hand wheel 162 that meshes with the pinion of the first intermediate wheel 161. As shown in Figure 3, the third small hand wheel 162 has a third small hand shaft 730 to which the third small hand 73 is attached.

[0022] The seventh wheel train 170 is a wheel train that drives the date wheel 50, and is provided with a first intermediate wheel 171 that meshes with the rotor pinion of the seventh motor 107, a second intermediate wheel 172 that meshes with the pinion of the first intermediate wheel 171, a third intermediate wheel 173 that meshes with the second intermediate wheel 172, a fourth intermediate wheel 174 that is arranged on the surface side of the main plate 15 and meshes with the pinion of the third intermediate wheel 173, and a driving wheel 175 that is arranged on the surface side of the main plate 15 and meshes with the pinion of the fourth intermediate wheel 174.

[0023] 3, the date wheel 50 is a ring-shaped part with internal teeth formed on its inner circumference, and the driving wheel 175 meshes with these internal teeth to rotate the date wheel 50. In addition, the center hand shaft 60, first small hand shaft 710, second small hand shaft 720, and third small hand shaft 730 are arranged on the inner peripheral side of the date wheel 50 so as not to interfere with the date wheel 50.

[0024] The switching device 700 shown in FIG. 2 is a device that operates in conjunction with the operation of the crown 3, and is a general switching mechanism that includes, in addition to the winding stem 701 to which the crown 3 is attached, a setting lever, a yoke, a click spring, a switch lever, a setting lever holder, a switch contact spring body, a switch contact spring, a switch wheel, etc. The winding stem 701 is provided in the movement 10 at the 3 o'clock position of the dial 5 in a plan view. A switching device 700 including a loveseat and the like in addition to the winding stem 701 is arranged along the outer periphery of the dial 5.

[0025] In the movement 10, in addition to the components described above, a gear train bridge, circuit board, antimagnetic plate, circuit retainer, etc. (not shown) are arranged on the back cover side of the main plate 15. In addition to the components described above, in the movement 10, a solar cell (not shown) is arranged on the dial 5 side of the main plate 15.

[0026] 4 is a block diagram showing the configuration of the electronic timepiece 1. The electronic timepiece 1 includes an input device 11, a timing device 12, a power supply device 13, a control device 20, a storage device 30, a display unit 40, and a drive mechanism 100. The input device 11 is configured to include the above-mentioned crown 3, button 4A, and button 4B.

[0027] The timekeeping device 12 includes a crystal oscillator and the like that is driven by power supplied from the power supply device 13, and outputs a clock signal based on the oscillation signal of the crystal oscillator. The power supply device 13 is the power source for the electronic timepiece 1, and in this embodiment is configured to include a solar panel, a charging circuit, and a secondary battery 14. The solar panel is a solar cell used for the timepiece, and is configured by connecting multiple solar cells in series. The charging circuit supplies power generated by the solar panel to the secondary battery 14, charging it. Note that the power supply device 13 is not limited to one that includes a solar panel and secondary battery 14, and may be any device that can supply power to the control device 20, etc.

[0028] The storage device 30 comprises a time data storage unit 31, a measurement time storage unit 32, a reset-to-zero position storage unit 33, and a hand position storage unit 34. The storage device 30 may be configured as a storage area within the timepiece IC, or may be configured as an external memory attached to the timepiece IC. The time data storage unit 31 stores the time displayed by each hand. Note that the electronic timepiece 1 of this embodiment displays the local time displayed by the hour hand 61, minute hand 62, and second hand 63, and the home time displayed by the small hour hand 711 and small minute hand 712 of the first small hand 71, so the time data storage unit 31 stores data for these two types of time. For this reason, the time data storage unit 31 may directly store two types of time data, local time data and home time data, or it may store data from which the two types of time data can be calculated by storing Coordinated Universal Time (UTC), time difference data for the local time, and time difference data for the home time.

[0029] The measured time memory unit 32 stores the time measured in the chronograph mode. In this embodiment, since the third small hand 73, which is a 1 / 20 second CG hand, is provided, the measured time memory unit 32 stores the time in 1 / 20 second units in addition to the measured time in hours, minutes, and seconds.

[0030] The zero-reset position memory unit 33 stores whether the zero-reset position of the first small hand 71 is set to the first indicating position indicating 0:00 or the second indicating position indicating 12:00 in the chronograph mode. The zero-reset position of the first small hand 71 means the hand positions of the small hour hand 711 and small minute hand 712 of the first small hand 71 at the start of measurement in the chronograph mode, i.e., the measurement start position. The small hour hand 711 of the first small hand 71 is a 12-hour hour hand that makes one rotation in 12 hours, and the scale indicated by the small hour hand 711 is the same when it is at a first indicating position indicating midnight and when it is at a second indicating position indicating 12 o'clock. On the other hand, as will be described later, the first small hand 71 is managed as a 24-hour hand position ranging from 0:00 to 23:59, and the first indicating position and the second indicating position are managed separately. Furthermore, because the small hour hand 711 and small minute hand 712 of the first small hand 71 are moved in conjunction with each other by a single fourth motor 104, the measurement start position of the first small hand 71, i.e., the zero-reset position, is set in hours and minutes. Therefore, one of two indication positions, the first indication position indicating 0:00 where the small hour hand 711 and small minute hand 712 are overlapping facing the 12 o'clock direction, or the second indication position indicating 12:00, is selected in the zero-reset position memory unit 33, and is set and stored as the measurement start position of the first small hand 71 in chronograph mode, i.e., the zero-reset position. The zero-reset position memory unit 33 also stores positions indicating 0 seconds as measurement start positions for the second hand 63, which is a second CG hand, and the third small hand 73, which is a 1 / 20 second CG hand.

[0031] The hand position storage unit 34 stores the hand position of each hand. For example, the hand position storage unit 34 has a hand position counter set for each hand driven by each motor 101 to 107, the count value of which is updated each time a drive pulse is input to each motor 101 to 107, and the count value of which is reset when the hand position detection device detects a reference position. For example, the hand position counter for the first small hand 71 driven by the fourth motor 104 is configured as an up / down counter that can count 60 minutes x 24 hours = 1,440 count values ​​because the fourth motor 104 drives the small hour hand 711 and small minute hand 712 in forward and reverse directions. For this reason, the hand position counter for the first small hand 71 is configured to be able to count from "0" to "1239," with the counter value "0" representing the first indicating position where the first small hand 71 points to 0:00, the counter value "720" representing the second indicating position where the first small hand 71 points to 12:00, and the counter value "1239" representing the position where the first small hand 71 points to 23:59. The hand position counter for the first small hand 71 counts up by one each time a drive pulse for forward rotation is input from the drive control unit 25 (described later) to the fourth motor 104, and counts down by one each time a drive pulse for reverse rotation is input from the drive control unit 25 to the fourth motor 104. Furthermore, when the counter value reaches "1239" and a drive pulse for forward rotation is input from the drive control unit 25 to the fourth motor 104, the counter value returns to "0." The hand position counters for the other hands are set in the same way according to each hand.

[0032] The control device 20 is configured with a timepiece IC that controls the electronic timepiece 1. The display control unit of this embodiment is configured with the control device 20. The control device 20 includes an input detection unit 21 , a display time control unit 22 , a chronograph control unit 23 , a mode hand control unit 24 , and a drive control unit 25 .

[0033] The input detection unit 21 detects input operations of the input device 11, and in this embodiment detects the pulled-out position, rotation direction and number of rotations of the crown 3, and the operation of pressing and releasing the buttons 4A and 4B.

[0034] The display time control unit 22 updates the time data in the time data storage unit 31 using the clock signal output from the timing device 12. In addition, in conjunction with updating the time data storage unit 31, the display time control unit 22 drives the drive mechanism 100 via the drive control unit 25 to drive the hour hand 61, minute hand 62, second hand 63, first small hand 71, fourth small hand 74, second small hand 72, and date wheel 50 of the display unit 40.

[0035] In the chronograph mode, the chronograph control unit 23 executes time measurement processing using the clock signal output from the timing device 12, stores the measured time in the measured time memory unit 32, and controls the drive of the third small hand 73, second hand 63, and first small hand 71 used as chronograph hands via the drive control unit 25. The mode hand control unit 24 controls the drive of the second small hand 72 via the drive control unit 25 . The drive control unit 25 outputs drive pulses to the motors 101-107 to control the driving of the motors 101-107.

[0036] [Switching to chronograph mode] Next, we will explain the switching control when a mode switching operation to chronograph mode is performed by the first operating unit in the control device 20, which is the display control unit of the electronic timepiece 1. The mode switching operation is appropriately set according to the input device 11 of the electronic timepiece 1. In this embodiment, in time display mode, the crown 3 is pulled out one position, and then the button 4B is pressed and released. With the second small hand 72 pointing to the "CHR" scale, which indicates chronograph mode, the time display mode is switched to chronograph mode by pushing the crown 3 back. In chronograph mode, pulling out the crown 3 and then pushing it back cancels the chronograph mode and switches to time display mode. Therefore, in this embodiment, the first operating unit that switches between the time display mode and the chronograph mode is composed of the crown 3 and button 4B. Switching to chronograph mode may involve switching directly from time display mode to chronograph mode, or from a mode other than time display mode, such as a time zone selection mode, to chronograph mode.

[0037] When the input detection unit 21 of the control device 20 detects the switching operation to the chronograph mode by the input device 11, the chronograph control unit 23 executes a zero reset process to move the third small hand 73, the second hand 63, the small hour hand 711, and the small minute hand 712 used as chronograph hands to the measurement start position. The third small hand 73, which is a 1 / 20 second CG hand and is a sub-second CG hand, is not used in the time display mode and is therefore stopped at the zero-reset position, i.e., the 0-second position. Therefore, when the chronograph control unit 23 starts the zero-reset process, it is not necessary to move the third small hand 73. However, in this embodiment, the chronograph control unit 23 performs a process of fast-forwarding the third small hand 73 one revolution in the forward direction to the zero-reset position. This allows the third small hand 73, which does not move in the time display mode, to move one revolution at a fast pace, allowing the user to easily recognize that the mode has been switched to chronograph mode. Note that the third small hand 73, which is a 1 / 20 second CG hand, makes one revolution per second during time measurement, so the time required to fast-forward one revolution to the zero-reset position can be set to less than one second, e.g., 0.7 seconds.

[0038] The chronograph control unit 23 starts the zeroing process of the second hand 63, which is the second CG hand, at the same time as starting the zeroing process of the third small hand 73. In this embodiment, the second hand 63, which also serves as the second CG hand, is used as the second hand in the time display mode, and therefore starts the process of moving the second hand 63 at high speed in the forward direction from a hand position indicating the seconds of the current time to the zero-set position, which is the zero-set position. Note that the maximum time required for moving the second hand 63 at high speed in the forward direction to the zero-set position is the time it takes for the second hand 63 to be fast-forwarded in the forward direction from a position indicating the one-second mark to the zero-set position, which is the time it takes for the second hand 63 to be fast-forwarded 59 seconds in the forward direction from a position indicating the one-second mark to the zero-set position, which is, for example, 0.9 seconds. Therefore, after switching to the chronograph mode, the zeroing process of the second hand 63 and the third small hand 73 is completed in less than one second. The reason why the second hand 63 and the third small hand 73 are fast-forwarded in the forward direction is because the third motor 103 and the sixth motor 106 that drive them are motors equipped with a single coil, and the fast-forward speed in the forward direction is faster than the fast-forward speed in the reverse direction, so both the second hand 63 and the third small hand 73 are fast-forwarded in the forward direction to return to zero.

[0039] The chronograph control unit 23 starts the zeroing process for the first small hand 71, which is a sub-clock, at the same time as starting the zeroing process for the second hand 63 and the third small hand 73. The zeroing process for the first small hand 71, which is a sub-clock, will be described with reference to the flowchart in FIG. 5. Note that the zeroing process for the first small hand 71 in this embodiment is performed under the prerequisite that the fourth motor 104 that drives the first small hand 71 has two coils and that the fast-forward frequency, i.e., the fast-forward speed, is the same in the forward and reverse directions. Also, as described above, the hand position of the first small hand 71 is managed by the hand position counter value "0" to "1439."

[0040] The chronograph control unit 23 first acquires the current hand position of the first small hand 71, which is the sub-dial, that is, the hand positions of the small hour hand 711 and small minute hand 712 that display the home time in the time display mode (step S1). Because the current hand position of the first small hand 71 is stored in the hand position memory unit 34, the chronograph control unit 23 acquires the hand position of the first small hand 71 by detecting the value of the hand position counter for the first small hand 71 in the hand position memory unit 34. Next, the chronograph control unit 23 determines whether the current hand position of the first small hand 71 is equal to or greater than 6:00 and less than 18:00 (step S2). Specifically, the chronograph control unit 23 determines whether the hand position counter value acquired in step S1 is equal to or greater than "360" indicating 6:00 and less than "1080" indicating 18:00.

[0041] If the chronograph control unit 23 determines YES in step S2, it sets the reset-to-zero position, i.e., the measurement start position, to the second indicated position of 12:00 (step S3). Then, the chronograph control unit 23 determines whether the current hand position is equal to or less than 12:00 (step S4). If the chronograph control unit 23 determines YES in step S4, it sets the rotation direction to forward (step S5), and if the chronograph control unit 23 determines NO in step S4, it sets the rotation direction to reverse (step S6).

[0042] If the chronograph control unit 23 determines NO in step S2, it sets the reset-to-zero position, i.e., the measurement start position, to the first indicated position of 0:00 (step S7). Then, the chronograph control unit 23 determines whether the current hand position is 18:00 or later or 0:00 (step S8). If the chronograph control unit 23 determines YES in step S8, it sets the rotation direction to forward (step S9), and if the chronograph control unit 23 determines NO in step S8, it sets the rotation direction to reverse (step S10).

[0043] Next, the chronograph control unit 23 saves the reset-to-zero position, that is, the measurement start position, set in steps S3 and S7 in the reset-to-zero position storage unit 33 and updates it (step S11). Next, the chronograph control unit 23 calculates the amount of hand movement, that is, the number of drive pulses of the fourth motor 104, based on the reset-to-zero position and rotation direction set from the current hand position of the first small hand 71 (step S12). Then, the chronograph control unit 23 executes the movement of the first small hand 71, which is the subdial, to the reset-to-zero position based on the set rotation direction and hand movement amount (step S13).

[0044] Through the above-described reset-to-zero processing, the first small hand 71 is reset to the measurement start position, which is either the first indicating position (0:00) or the second indicating position (12:00), whichever is the position that results in the shortest movement time between the first small hand 71, i.e., the small hour hand 711 which is the first pointer, and the small minute hand 712 which is the second pointer. For example, when the current time of the home time indicated by the first small hand 71 is 17:05 and an operation to switch to the chronograph mode is performed, a YES determination is made in step S2 and the reset-to-zero position is set to the second indicating position of 12:00 in step S3, a NO determination is made in step S4 and the rotation direction is set to reverse in step S6. Then, in step S11, the chronograph control unit 23 updates the zero-reset position to the second indicated position of 12:00, and in step S12, calculates the amount of hand movement to 5 hours and 5 minutes based on the relationship between the current hand position of 17:05 and the zero-reset position, and in step S13, moves the fourth motor 104 reversely for 5 hours and 5 minutes via the drive control unit 25. The fourth small hand 74, which is the AM / PM hand, is driven in conjunction with the first small hand 71, and is moved reversely to a downward position indicating 12 o'clock. In this way, the zero-reset position of the first small hand 71 can be selected from the first indication position (0:00) and the second indication position (12:00), and because the fast-forward speed of the fourth motor 104 is the same in both the forward and reverse directions, the time required for the first small hand 71 to move to the measurement start position (reset position) can be minimized when switching to chronograph mode. In other words, because the zero-reset position of the first small hand 71, which is a sub-dial, is the first indication position or the second indication position and can be fast-forwarded at the same speed in both the forward and reverse directions, it can be moved to the zero-reset position with a maximum of six hours' worth of hand movement. In this embodiment, the maximum time required for the small hour hand 711 and small minute hand 712, which are driven by the fourth motor 104, to be fast-forwarded to the zero-reset position is 3.5 seconds.

[0045] [Time measurement control in chronograph mode] After switching to the chronograph mode, the chronograph control unit 23 starts time measurement when the input detection unit 21 detects that a button operation to start time measurement has been performed. In this embodiment, time measurement starts when button 4A is pressed. Therefore, button 4A is a third operation unit that instructs the start of measurement in the chronograph mode. In this embodiment, the condition for permitting button operation to start time measurement is when the second CG hand and fractional second CG hand used in the chronograph have completed moving to the zero-reset position, and even before the first small hand 71 of the subdial has returned to zero, if the second hand 63, which is the second CG hand, and the third small hand 73, which is the 1 / 20 second CG hand, move to the zero-reset position, i.e., the 0-second position, button operation to start time measurement is permitted and time measurement begins. As described above, the maximum time it takes for the second hand 63 to move to the zero-reset position is 0.9 seconds, and the time it takes for the third small hand 73 to make one rotation is 0.7 seconds. Therefore, after the user switches to chronograph mode, button operation to start time measurement is permitted once a maximum of 0.9 seconds has elapsed until the second hand 63 and third small hand 73 return to the zero-reset position, and time measurement can therefore start even before the first small hand 71 has returned to the zero-reset position.

[0046] Conventionally, the following two patterns are known as conditions for permitting a button operation to start time measurement. The first pattern allows measurement to begin even while one of the chronograph hands is moving or resetting to zero. The advantage of this pattern is that the user can start measurement immediately without having to wait for the chronograph mode to be ready. The disadvantage is that because operations can be performed while the hands are moving, it can be difficult to know what the hands are displaying. The second pattern allows measurement to begin only after all the hands used for the chronograph have moved to their zero-reset positions. The advantage of the second pattern is that it is clear that the watch has switched to chronograph mode, it is easy to understand, and it is less likely to be operated incorrectly. The disadvantage is that it takes a long time to wait for the hands to move to their zero-reset positions.

[0047] In contrast, the pattern of this embodiment starts time measurement between the first pattern and the second pattern, and measurement becomes possible once the third small hand 73, which is the sub-second CG hand used in the chronograph, and the second hand 63, which is the second CG hand, have completed moving to their zero-reset positions. Therefore, the advantages and disadvantages of the pattern of this embodiment are intermediate between those of patterns 1 and 2. Specifically, the reason for selecting the second hand 63 and the third small hand 73 as the hands that complete their movement before measurement operation becomes possible is that the first small hand 71, which is a subdial, takes longer to reset to zero than the other hands, so if you wait for the first small hand 71 to complete its movement, the disadvantage of not being able to start measurement immediately after switching modes is significant. On the other hand, for the second hand 63 and the third small hand 73, which are hands smaller than the second hand, it is difficult for the user to know whether measurement has started unless measurement is started from the reset-to-zero position, and yet their movement time is shorter than that of the first small hand 71, which is a subdial, so the disadvantage of waiting time is small. The first small hand 71, which is a subdial, indicates the minutes and hours of the measurement time, so it is not used to display the measurement time until one minute has elapsed. For this reason, even if the first small hand 71, which returns to zero in approximately 3.5 seconds, is moved to return to zero immediately after time measurement begins, the user will be focusing on the second hand 63 and the third small hand 73, so there is little impact even if time measurement begins before the first small hand 71 returns to zero.

[0048] Furthermore, in this embodiment, a sub-second CG hand indicating fractional seconds (e.g., 1 / 100th or 1 / 20th of a second) is provided as a chronograph hand. While this sub-second CG hand is operating or begins to operate, fast-forwarding of the other hands and the date indicator 50 is stopped. For example, when the local time reaches midnight and fast-forwarding of the date indicator 50 is necessary to change the date display, if the sub-second CG hand is operating, fast-forwarding of the date indicator 50 begins after the sub-second CG hand stops. Furthermore, if chronograph measurement is started by an operation while the date indicator 50 is fast-forwarding, and the sub-second CG hand starts to operate, the date indicator 50 is stopped even while it is moving. Another example is when automatic reception by the GPS satellite signal reception function is activated during time measurement, causing fast-forwarding of the hour hand 61, minute hand 62, and date indicator 50. In this case, priority is given to the operation of the sub-second CG hand, so fast-forwarding of the other hands begins after the sub-second CG hand stops. The reason for this control is that if the operation of the sub-second CG hand were controlled by software while maintaining low power consumption, the processing load would be extremely high, and if other operations were performed in parallel, processing time delays would occur, making it difficult for the sub-second CG hand to operate in accordance with the actual measured time. Therefore, as in this embodiment, the processing load can be reduced by stopping the fast forwarding of the other hands when the third small hand 73, which is the 1 / 20 second CG hand, is operating.

[0049] When the chronograph mode is switched to and the second hand 63 and third small hand 73 return to the 0-second position, which is the reset-to-zero position, the chronograph control unit 23 accepts an operation to start time measurement using button 4A. Therefore, when the input detection unit 21 detects that button 4A has been pressed, the chronograph control unit 23 starts time measurement and moves the third small hand 73, second hand 63, and first small hand 71. Note that, in order to reduce the load on the time measurement process, the third small hand 73, which is a 1 / 20-second CG hand, moves for a maximum of one minute from the start of time measurement and then stops at the 0-second position. Furthermore, when a split operation or stop operation, which will be described later, is performed, the second hand 63 and first small hand 71 stop at a position that indicates the measured time at the time of the operation, and the third small hand 73 indicates the seconds at the time of the operation. When button 4A is pressed while time measurement is in progress, chronograph control unit 23 stops time measurement and stops the movement of third small hand 73, second hand 63, and first small hand 71. When button 4A is pressed while time measurement is stopped, chronograph control unit 23 resumes time measurement. Even when time measurement is resumed, third small hand 73 continues to move for only one minute. The chronograph control unit 23 automatically stops time measurement when the measured time of the chronograph reaches 12 hours, that is, when the small hour hand 711 of the first small hand 71 moves one revolution and returns to the reset-to-zero position.

[0050] Pressing button 4B while time measurement is stopped resets the third small hand 73, second hand 63, and first small hand 71, returning them to their zero-reset positions, just as when switching to chronograph mode as shown in Figure 5. For this reason, button 4B is the second operating unit through which the reset operation is performed. For example, if the reset position when switching to chronograph mode is 0:00, and after performing chronograph measurement for nine hours, button 4B is used to perform a reset operation, the position of first small hand 71 immediately before the reset is 9:00, so in the flowchart shown in Figure 5, step S2 is judged as YES, step S4 is judged as YES, first small hand 71 is moved forward to the 12:00 position, and the new reset position is updated to 12:00. Next, if button 4A is pressed to start chronograph measurement, and after measuring for five hours, button 4B is used to perform the reset operation, the position of first small hand 71 immediately before the reset is 17:00, so in the flowchart of Figure 5, step S2 will be judged as YES and step S4 will be judged as NO, first small hand 71 will be moved in the reverse direction to the 12:00 position, and the new zero-reset position will be updated to 12:00. For this reason, the zero-reset position of the first small hand 71 stored in the zero-reset position storage unit 33 of the storage device 30 is updated when switching to the chronograph mode and when resetting time measurement in the chronograph mode. The zero-reset position of the first small hand 71 stored in the zero-reset position storage unit 33 is used when there is a discrepancy between the time measured by the chronograph and the displayed position of the hand, such as when releasing a split, as described below, or when restarting while the chronograph hand is reset to zero.

[0051] When restarting after resetting in chronograph mode, measurement will start even if all chronograph hands have not yet returned to zero. In other words, if a start command is given before the chronograph hands have returned to their zero positions, the hands will operate as follows: The third small hand 73, which is the 1 / 20 second chronograph hand, is fast-forwarded in the forward direction until it returns to zero. However, if a start command is received before the third small hand 73 returns to the zero position, the third small hand 73 does not stop at the zero-return position (0 second position) but continues fast-forward until it catches up with the measured time. Once the third small hand 73 catches up with the measured time, the third small hand 73 begins moving in 1 / 20 second increments. The forward fast-forward frequency of the third small hand 73 is, for example, 85.3 Hz. In this embodiment, the third small hand 73 completes one rotation by inputting 60 drive pulses to the sixth motor 106. Therefore, theoretically, if the fast-forward frequency is 60 Hz or higher, the third small hand 73 can catch up with the measured time. The second hand 63, which is the second CG hand, is quickly advanced in the forward direction to return to zero, but if a start command is given before it returns to the zero position, and the measured time is already 1 second or more, the second hand 63 will not stop at the 0 second position, which is the zero position, but will continue to advance quickly until it catches up with the measured time display, just like the operation of the third small hand 73. As described above, the first small hand 71 of the subdial, which is the hour and minute CG hand, moves quickly to and stops at the zero-reset position that is set by the position of the first small hand 71 immediately before reset. In other words, the first small hand 71 returns to zero in a maximum of about 3.5 seconds, so the first small hand 71 stops at the zero-reset position until one minute of measurement time has elapsed and the first small hand 71 begins to move.

[0052] [Split measurement control] Split measurement is a measurement method that allows you to read the split time, which is the elapsed time from the start, by stopping only the display of the chronograph hands while continuing to measure time with the chronograph. To perform this split measurement, as with normal chronograph time measurement, when the button 4A is pressed after switching to the chronograph mode, the chronograph control unit 23 starts chronograph measurement (step S21), as shown in Fig. 6. Therefore, the second hand 63, third small hand 73, and first small hand 71, which are chronograph hands, are in a moving state (step S22). The chronograph control unit 23 determines whether or not the button 4B has been pressed to perform a split operation while the chronograph hands are moving in step S22 (step S23). If the determination in step S23 is NO, the chronograph control unit 23 continues the state of moving the chronograph hands in step S22, that is, the time measurement state. On the other hand, if the result of the determination in step S23 is YES, that is, if the button 4B is pressed, the chronograph control unit 23 stops the chronograph hands in the split display (step S24). At this time, the chronograph control unit 23 continues time measurement, that is, updating the measured time stored in the measured time storage unit 32. The chronograph control unit 23 determines whether or not the button 4B has been pressed to perform a split release operation while the chronograph hands are stopped in the split display in step S24 (step S25). If the determination in step S25 is NO, the chronograph control unit 23 maintains the state in which the chronograph hands are stopped in the split display in step S24, and continues updating the duration in the measurement time storage unit 32.

[0053] On the other hand, if the answer to step S25 is YES, that is, if the button 4B is pressed to perform the split release operation, the chronograph control unit 23 executes the process of step S30 to fast-forward the chronograph hands to the measured time. The processing of step S30 is shown in the flowchart of Fig. 7. The chronograph control unit 23 acquires the chronograph measurement time by referring to the measurement time storage unit 32 (step S31). Furthermore, the chronograph control unit 23 refers to the reset-to-zero position storage unit 33 and determines whether the reset-to-zero position is the first indicated position, 0:00 (step S32).

[0054] If the chronograph control unit 23 determines NO in step S32, that is, if the reset-to-zero position is 12:00, it adds 12 hours to the chronograph measurement time for hand position conversion (step S33). That is, because the hand position of the first small hand 71 stored in the hand position memory unit 34 is based on a 24-hour system, if the reset-to-zero position is 12:00 and the chronograph measurement time is one hour, the hand position indicated by the first small hand 71 must be 13:00, that is, "780" on the hand position counter. Therefore, by adding a 12-hour offset amount to the chronograph measurement time, it is possible to convert the hand position of the first small hand 71 to that of the 24-hour system. Note that the processing of step S33 is solely for determining the hand position of the first small hand 71, and the measurement time stored in the measurement time memory unit 32 is continuously updated by the clock signal. When the chronograph control unit 23 determines YES in step S32 or after performing the offset process in step S33, it converts the hand positions of the first small hand 71, the second hand 63, and the third small hand 73 based on the chronograph measurement time (step S34). In step S34, the chronograph control unit 23 converts the hour and minute data of the chronograph measurement time set in accordance with the reset-to-zero position into the hand position of the first small hand 71. The chronograph control unit 23 also converts the second and fractional second data (1 / 20 second) of the chronograph measurement time into the hand positions of the second hand 63 and the third small hand 73. Because the reset-to-zero positions of the second hand 63 and the third small hand 73 are always 0 seconds, offset conversion is not necessary.

[0055] Next, the chronograph control unit 23 calculates the amount of movement from the positions of the first small hand 71, second hand 63, and third small hand 73 that were stopped during the split, i.e., the hand positions stored in the hand position memory unit 34, to the hand positions converted in step S34 (step S35). Then, the chronograph control unit 23 controls the fourth motor 104, the third motor 103, and the sixth motor 106 via the drive control unit 25 to start fast-forwarding the first small hand 71, second hand 63, and third small hand 73 in the forward direction by the amount of movement calculated in step S35 (step S36). By this fast-forwarding in step S36, the first small hand 71, second hand 63, and third small hand 73, which are the chronograph hands, are fast-forwarded from the positions where they were stopped during the split to a position that indicates the current chronograph measurement time when the split is released.

[0056] When the processing of step S30 shown in Fig. 7 is completed, the movement of the chronograph hands continues as shown in Fig. 6 (step S26). Pressing button 4B while the chronograph hands are continuing to move causes the display to change to split, and then pressing button 4B again cancels the split. Pressing button 4A while the chronograph hands are moving stops chronograph measurement, and pressing button 4B in this stopped state resets the chronograph measurement time and returns each chronograph hand to zero.

[0057] [Switching to time display mode] Next, we will explain the control when canceling chronograph mode and switching to time display mode. The operation for canceling chronograph mode can be set as desired, but in this embodiment, as described above, pulling out and pushing back the crown 3 cancels chronograph mode and switches to time display mode. At this time, the second small hand 72 switches to displaying the time display mode, for example, the day of the week. Furthermore, because the hour hand 61 and minute hand 62 continue to display the local time even in chronograph mode, they continue to display the time even when chronograph mode is canceled. Meanwhile, the display time control unit 22 switches the second hand 63 to display the seconds of the current time, and the third small hand 73 moves to the zero-reset position, i.e., the 0-second position.

[0058] Furthermore, the display time control unit 22 moves the first small hand 71 of the subdial to the current time position. The control of the movement of this first small hand 71 will be described with reference to the flowchart in FIG. When the chronograph mode is released, the display time control unit 22 acquires the hand position A of the first small hand 71, which is the subdial when the chronograph mode is released, from the hand position storage unit 34 (step S41). Next, the display time control unit 22 acquires the time of the first small hand 71, which is the current subdial, from the time data storage unit 31 (step S42). Next, the display time control unit 22 acquires hand position B of the current subdial time, that is, hand position B indicating the home time (step S43). The display time control unit 22 determines whether the difference between hand position B and hand position A is less than 12 hours (step S44), and if the result of step S44 is YES, sets the direction of rotation to forward (step S45), and if the result of step S44 is NO, sets the direction of rotation to reverse (step S46). Next, the display time control unit 22 calculates the amount of movement of the first small hand 71 according to each rotation direction (step S47), and fast-forwards the first small hand 71 to the current time position in the set rotation direction and amount of movement (step S48).

[0059] For example, if the zero reset position in the chronograph mode is the second indicating position, 12:00, and one hour is measured before the chronograph mode is canceled, hand position A of the first small hand 71 will point to 13:00. Meanwhile, suppose hand position B, the current time indicated by the first small hand 71, i.e., the home time, is 3:15. Hand position BA is calculated by rotating the watch forward from hand position A to hand position B. Therefore, by regarding hand position B as 24 hours + 3 hours 15 minutes, hand position BA becomes 14 hours 15 minutes, which is determined to be more than 12 hours. Therefore, the direction of rotation is set to the reverse direction, and the amount of reverse hand movement from hand position A, 13:00, to hand position B, 3:15, is 9 hours 45 minutes, so the first small hand 71 moves forward 9 hours 45 minutes in the reverse direction. As a result of the above, the watch switches to time display mode, and the hour hand 61, minute hand 62, and second hand 63 display the hours, minutes, and seconds of the local time, the first small hand 71 displays the hours and minutes of the home time, the fourth small hand 74 displays AM or PM of the home time, and the third small hand 73 stops at the zero-return position, i.e., the 0-second position.

[0060] [Effects of the embodiment] In this embodiment, when transitioning to chronograph mode or resetting the measurement display, the first small hand 71 can be set to the first or second position, whichever of the two positions—the first small hand 71 requires the shortest movement time—as the zero-reset position based on the displayed time and measurement time of the first small hand 71. This allows the first small hand 71 to begin zero-reset movement. Therefore, if the zero-reset position for starting measurement in chronograph mode is always set to the first position, 0:00, the maximum movement of the first small hand 71 is 12 hours. However, the maximum movement of the first small hand 71 to the zero-reset position can be reduced to 6 hours, half the required movement time. This reduces the user's waiting time for the display and measurement time during mode switching and the operation, improving user operability and convenience. The same effect can also be achieved when resetting the chronograph after chronograph measurement has been performed.

[0061] The zero-reset position memory unit 33 is provided, which stores the zero-reset position of the first small hand 71 each time it is updated. Therefore, when the display time of the first small hand 71 is to be adjusted to the measured time after the display time differs from the measured time, such as when a split is released, the amount of fast-forward movement of the first small hand 71 can be easily calculated using the zero-reset position memory unit 33 and the measured time memory unit 32, and the fast-forward process can be easily executed. In other words, if the zero-reset position is not stored, the position at the time of split release must be calculated by counting the time from the start of the split to the release of the split and adding this to the hand position to calculate the display position. This requires additional storage space and a timer for time measurement, resulting in heavy resource consumption. In contrast, the provision of the zero-reset position memory unit 33, as in this embodiment, eliminates the need to separately count the time from the start of the split to the release of the split.

[0062] [Variations] The first hand that serves as the hour CG hand in chronograph mode is not limited to the small hour hand 711 of the subdial, and the hour hand 61 may be used as the first hand. Because the hour hand 61 also displays time in 12-hour format, the measurement start position (reset position) can be selected from the first indication position indicating midnight or the second indication position indicating 12 o'clock. Note that the second hand that serves as the minute CG hand in chronograph mode is also not limited to the small minute hand 712, and the minute hand 62 may be used as the second hand. In this case, the minute hand 62 that serves as the minute CG hand is independently driven by the second motor 102, and therefore its measurement start position can be fixed at the position indicating midnight.

[0063] In the above embodiment, the fourth motor 104 with two coils that has the same fast-forward speed in both the forward and reverse directions is used as the motor that drives the first pointer that serves as the hour CG hand in the chronograph mode, but a motor with different fast-forward speeds in each direction may also be used. In this case, the threshold time for selecting the first and second indicated positions that are the return-to-zero positions, i.e., the time for determining the hand positions in steps S2, S4, and S8 in Fig. 5, can be set so that the shorter movement time can be selected taking into account the difference in fast-forward speed between the forward and reverse directions.

[0064] [summary] The electronic watch disclosed herein is an electronic watch having at least two modes, a time display mode and a chronograph mode, and is equipped with a first operating unit for performing a mode switching operation to switch between the modes, a first hand that displays the hour of the time in a 12-hour format in the time display mode and displays the hour of the measured time in the chronograph mode, and a display control unit that moves the first hand quickly forward to the measurement start position in the chronograph mode based on the mode switching operation to switch to the chronograph mode, and is characterized in that the display control unit distinguishes and manages two indication positions of the first hand in the time display mode: a first indication position where the first hand indicates midnight and a second indication position where the first hand indicates 12 o'clock, and when switching to the chronograph mode, sets the indication position of the two indication positions which the first hand moves to the shorter time as the measurement start position based on the displayed time of the first hand at the time of the switching operation, and moves the first hand to the set measurement start position. According to the electronic timepiece of the present disclosure, the display control unit can select and set the measurement start position in chronograph mode from two positions: a first position indicating midnight and a second position indicating 12 o'clock. Therefore, based on the displayed time of the first hand when switching to chronograph mode, the measurement start position that requires the shortest movement time of the first hand can be selected. Therefore, the time required to move the first hand to the measurement start position can be shortened compared to when the measurement start position in chronograph mode is always set to the first position indicating midnight.

[0065] In the electronic timepiece of the present disclosure, it is preferable that in the chronograph mode, a second operating unit is provided in which a reset operation is performed to reset time measurement, and when the reset operation is performed, the display control unit sets the indication position of the two indication positions that has the shorter movement time of the first hand as the measurement start position based on the hand position of the first hand, and moves the first hand to the set measurement start position. According to the electronic timepiece of the present disclosure, the display control unit can set and move the first hand to a measurement start position that requires the shortest movement time from the two indicated positions based on the current position of the first hand, even during a reset operation. Therefore, the time required to move the first hand to the measurement start position can be shortened even during a reset.

[0066] In the electronic timepiece of the present disclosure, it is preferable that the electronic timepiece is provided with a second hand that operates in conjunction with the first hand and displays the minutes, and that the display control unit manages the position where the first hand and the second hand indicate 00:00 as the first indicating position and the position where they indicate 12:00 as the second indicating position, and when switching to the chronograph mode, sets the position of the two indicating positions that takes the first hand and the second hand the shortest to move as the measurement start position based on the displayed time of the first hand and the second hand at the time of switching operation, and moves the first hand and the second hand to the set measurement start position. In the electronic timepiece disclosed herein, the first and second hands move in tandem, allowing them to be driven by a single motor. As a result, the measurement start position when switching modes can be selected from either the first indicating position indicating 0:00 or the second indicating position indicating 12:00, thereby shortening the time it takes to move the first and second hands to their measurement start positions compared to when the measurement start position is always set to the first indicating position.

[0067] The electronic timepiece of the present disclosure preferably includes a third hand that operates in conjunction with the first hand and makes one rotation in 24 hours. The electronic watch disclosed herein is equipped with a third hand that is linked to the first hand and rotates once every 24 hours, allowing the user to easily check whether the first hand is displaying the morning time or the afternoon time.

[0068] In the electronic timepiece of the present disclosure, it is preferable that a motor for driving the first hand is provided, the motor having two coils and being able to drive the first hand in both forward and reverse directions at the same speed. According to the electronic timepiece of the present disclosure, the motor that drives the first hand is equipped with two coils, and can drive the first hand in both the forward and reverse directions at the same speed, thereby minimizing the time it takes for the first hand to move to the measurement start position.

[0069] In the electronic timepiece disclosed herein, it is preferable that the electronic timepiece comprises a fourth hand that displays measured times in seconds or less in the chronograph mode and has a position indicating 0 seconds set as the measurement start position, and a third operating unit that instructs the start of measurement in the chronograph mode, and that the display control unit fast-forwards the fourth hand to the measurement start position based on a mode switching operation to switch to the chronograph mode, and that after the fourth hand has moved to the measurement start position, the display control unit accepts an instruction to start measurement from the third operating unit and starts time measurement of the chronograph. According to the electronic timepiece of the present disclosure, when switching to chronograph mode, the fourth hand quickly moves to the measurement start position indicating 0 seconds, allowing the user to easily confirm that the mode has been switched to chronograph mode. Also, because the fourth hand displays the chronograph measurement time in seconds or less, it takes only a short time to quickly move it to the measurement start position, and chronograph measurement can begin once the fourth hand has moved to the measurement start position. Therefore, time measurement in chronograph mode can begin before the first hand moves to the measurement start position, thereby shortening the wait time until measurement begins.

[0070] In the electronic timepiece of the present disclosure, it is preferable that the upper limit of the time that can be measured in the chronograph mode is 12 hours. According to the electronic watch of the present disclosure, the maximum time that can be measured in chronograph mode is 12 hours, so the first 12-hour hand moves only one revolution from the measurement start position in chronograph mode, allowing the user to easily check the measured time.

[0071] The electronic timepiece of the present disclosure preferably includes a storage unit that stores the time in the time display mode, the measured time in the chronograph mode, and the hand position of the first hand. The electronic watch disclosed herein is equipped with a memory unit that stores the time in time display mode, the measured time in chronograph mode, and the hand position of the first hand, so that when switching between time display mode and chronograph mode using a mode switching operation, the time and measured time can be easily switched and displayed using the first hand.

[0072] In the electronic timepiece of the present disclosure, it is preferable that the storage unit stores the set measurement start position. According to the electronic watch of the present disclosure, the measurement start position set by the display control unit is stored in the memory unit, so if a discrepancy occurs between the measurement time and the time indicated by the chronograph hands during a split operation, for example, it is possible to easily execute a process to fast-forward the chronograph hands to the measurement time when the split is released. [Explanation of symbols]

[0073] 1...electronic timepiece, 3...crown, 4A...button, 4B...button, 10...movement, 11...input device, 12...timing device, 13...power supply device, 14...secondary battery, 20...control device, 21...input detection unit, 22...display time control unit, 23...chronograph control unit, 24...mode hand control unit, 25...drive control unit, 30...storage unit, 31...time data storage unit, 32...measured time storage unit, 33...reset-to-zero position storage unit, 34...hand position storage unit, 40...display unit, 71...first small hand, 74...fourth small hand, 100...drive mechanism, 101...first motor, 102...second motor, 103...third motor, 104...fourth motor, 105...fifth motor, 106...sixth motor, 107...seventh motor, 711...small hour hand, 712...small minute hand.

Claims

1. An electronic timepiece having at least two modes: a time display mode and a chronograph mode, a first operation unit for performing a mode switching operation to switch the mode; a first hand that displays the hour of the time in a 12-hour format in the time display mode and displays the hour of the measured time in the chronograph mode; a display control unit that fast-forwards the first hand to a measurement start position in the chronograph mode based on a mode switching operation for switching to the chronograph mode, The display control unit In the time display mode, the first hand is managed by distinguishing between two indicating positions, namely, a first indicating position where the first hand indicates 0 o'clock and a second indicating position where the first hand indicates 12 o'clock; When switching to the chronograph mode, the indication position of the two indication positions, which has the shorter movement time of the first hand, is set as the measurement start position based on the displayed time of the first hand at the time of switching operation, and the first hand is moved to the set measurement start position. An electronic watch characterized by:

2. 2. The electronic timepiece according to claim 1, a second operation unit for performing a reset operation to reset time measurement in the chronograph mode; When the reset operation is performed, the display control unit sets one of the two indication positions, which has a shorter movement time of the first pointer, as the measurement start position based on the needle position of the first pointer, and moves the first pointer to the set measurement start position. An electronic watch characterized by:

3. 2. The electronic timepiece according to claim 1, a second hand that moves in conjunction with the first hand and displays minutes; The display control unit a position where the first hand and the second hand indicate 0:00 is defined as the first indicating position, and a position where the first hand and the second hand indicate 12:00 is defined as the second indicating position; When switching to the chronograph mode, the measurement start position is set to one of the two indicated positions, which has a shorter movement time of the first hand and the second hand, based on the displayed time of the first hand and the second hand at the time of switching operation, and the first hand and the second hand are moved to the set measurement start position. An electronic watch characterized by:

4. 2. The electronic timepiece according to claim 1, The third hand operates in conjunction with the first hand and makes one rotation in 24 hours. An electronic watch characterized by:

5. 2. The electronic timepiece according to claim 1, a motor that drives the first pointer; The motor has two coils and is capable of driving the first pointer in both forward and reverse directions at the same speed. An electronic watch characterized by:

6. 2. The electronic timepiece according to claim 1, a fourth hand that displays measured time in seconds in the chronograph mode and has a measurement start position set to indicate 0 seconds; a third operation unit for instructing the start of measurement in the chronograph mode, the display control unit moves the fourth hand to the measurement start position at a fast speed based on a mode switching operation for switching to the chronograph mode, After the fourth hand moves to the measurement start position, the display control unit receives an instruction to start measurement from the third operation unit and starts time measurement of the chronograph. An electronic watch characterized by:

7. 2. The electronic timepiece according to claim 1, The maximum time that can be measured in the chronograph mode is 12 hours. An electronic watch characterized by:

8. 2. The electronic timepiece according to claim 1, a memory unit that stores the time in the time display mode, the measured time in the chronograph mode, and the hand position of the first hand; An electronic watch characterized by:

9. 9. The electronic timepiece according to claim 8, The storage unit stores the set measurement start position. An electronic watch characterized by:

Images