EP4647855A1

EP4647855A1 - Electronic timepiece

Info

Publication number: EP4647855A1
Application number: EP25174662.4A
Authority: EP
Inventors: Takuya Tanabe
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2024-05-10
Filing date: 2025-05-06
Publication date: 2025-11-12
Also published as: JP2025171557A; CN120928668A

Abstract

An electronic timepiece includes a first operation section configured to perform a mode switching operation for switching between a time display mode and a chronograph mode, a first indicating hand configured to display an hour of a time in a 12-hours system in the time display mode and display an hour of a measurement time in the chronograph mode, and a display control section configured to move the first indicating hand to a measurement start position in the chronograph mode by fast forwarding based on the mode switching operation for switching to the chronograph mode, in which the display control section is configured to distinguish and manage each of indicating position of 0 o'clock and 12 o'clock and set, when switching to the chronograph mode, an indicating position having a shorter movement time of the first indicating hand among two indicating positions to the measurement start position, based on a display time of the first indicating hand at a time of the switching operation, and move the first indicating hand to the set measurement start position.

Description

BACKGROUND

1. Technical Field

The present disclosure relates to an electronic timepiece.

2. Related Art

JP-A-2016-200502 discloses an electronic timepiece including a sub-dial that indicates a time of a selected time zone, in addition to an hour hand and a minute hand that indicate a local time. The sub-dial of the electronic timepiece is a 24-hours system clock including a minute hand that makes one rotation in one hour and an hour hand that rotates once when the minute hand rotates 24 times, that is, one rotation in 24 hours, and is driven by one motor.
The electronic timepiece of JP-A-2016-200502 has a chronograph mode in addition to a time display mode. The sub-dial functions as a chronograph minute hand and a chronograph hour hand in the chronograph mode. Therefore, when the mode is switched to the chronograph mode by an operation of a user, the hour and minute hands of the sub-dial move in a faster rotation direction either clockwise or counterclockwise from a hand position immediately before the switching to the chronograph mode to a zero return position indicating 0:00.
In the electronic timepiece, when the mode is switched to the chronograph mode, there is a problem that it is necessary to move the hour hand of the sub-dial by a maximum of 12 hours to move the hour hand to the zero return position, and it takes time to complete the movement. Therefore, an electronic timepiece that can move an indicating hand that functions as a chronograph hour hand to the zero return position in a short time when switched to the chronograph mode is required.

SUMMARY

According to an aspect of the present disclosure, an electronic timepiece having at least two modes of a time display mode and a chronograph mode, includes a first operation section configured to perform a mode switching operation for switching the mode, a first indicating hand configured to display an hour of a time in a 12-hours system in the time display mode and display an hour of a measurement time in the chronograph mode, and a display control section configured to move the first indicating hand to a measurement start position in the chronograph mode by fast forwarding based on the mode switching operation for switching to the chronograph mode, in which the display control section is configured to distinguish and manage two indicating positions of a first indicating position at which the first indicating hand indicates 0 o'clock and of a second indicating position at which the first indicating hand indicates 12 o'clock in the time display mode, and set, when switching to the chronograph mode, an indicating position having a shorter movement time of the first indicating hand among the two indicating positions to the measurement start position, based on a display time of the first indicating hand at a time of the switching operation, and move the first indicating hand to the set measurement start position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing an electronic timepiece according to an embodiment.
FIG. 2 is a plan view showing a main portion of a movement of the electronic timepiece according to the embodiment.
FIG. 3 is a plan view showing a main portion of a movement of the electronic timepiece according to the embodiment.
FIG. 4 is a block diagram showing a configuration of an electronic timepiece according to the embodiment.
FIG. 5 is a flowchart showing a switching process to a chronograph mode of the embodiment.
FIG. 6 is a flowchart showing a process when a split operation is performed in the embodiment.
FIG. 7 is a flowchart showing a process after split is released in the embodiment.
FIG. 8 is a flowchart showing a switching process to a time display mode of the embodiment.

DESCRIPTION OF EMBODIMENTS

In the following, an electronic timepiece 1 of the present embodiment will be described based on the drawings.
As shown in FIG. 1, the electronic timepiece 1 includes an exterior case 2, a crown 3 for an external operation, and two buttons 4A and 4B. As will be described later, a dial 5, a movement 10, and the like are stored in the exterior case 2. The crown 3 is provided at a 3 o'clock direction of the dial 5 in a plan view, and the buttons 4A and 4B are provided at 2 o'clock and 4 o'clock directions, respectively.
The electronic timepiece 1 includes an hour hand 61, a minute hand 62, a seconds hand 63, which are center hands 6, a first small hand 71, a second small hand 72, a third small hand 73, a fourth small hand 74, and a date indicator 50 as a display section 40 that displays the time and the like.
A center through-hole (not shown) penetrating the dial 5 is formed in the planar center of the dial 5, and a center hand shaft 60 to which the center hands 6 are attached is disposed in the center through-hole.
The dial 5 has three small windows (sub-dials). That is, as shown in FIG. 1, the dial 5 is provided with a first small window 71A having a circular shape and a first small hand 71 in the 6 o'clock direction, a second small window 72A having a circular shape and a second small hand 72 in the 9 o'clock direction, and a third small window 73A having a circular shape and a third small hand 73 in the 12 o'clock direction with respect to the planar center provided with the center hand shaft 60. A rectangular date window 51 is provided in a direction between 4 o'clock and 5 o'clock (4.5 o'clock direction) with respect to the planar center of the dial 5. A date indicator 50, which is a calendar wheel, is disposed on a back surface side of the dial 5, and the date indicator 50 is visible from a date window 51.
A fourth small window 74A having a circular shape and a fourth small hand 74 are provided between the planar center of the dial 5 and the date window 51.
Therefore, in the dial 5, in addition to the center through-hole formed in the planar center and into which the center hand shaft 60 is inserted, four through-holes (not shown) into which the small hand shafts of the first small hand 71, the second small hand 72, the third small hand 73, and the fourth small hand 74 are inserted, and the date window 51 are formed.
The electronic timepiece 1 is configured to select a chronograph mode that executes a stopwatch function in addition to the time display mode. In the chronograph mode, some of the indicating hands function as chronograph hands.
The hour hand 61 and the minute hand 62 display the hours and minutes of the local time in both the time display mode and the chronograph mode. The seconds hand 63 displays the seconds of the local time in the time display mode, and functions as a seconds chronograph hand, that is, a seconds CG hand in the chronograph mode.
The first small hand 71 is a home time hand indicating a time of the time zone set in advance by a user in the time display mode, and is configured with a small hour hand 711 and a small minute hand 712 that operate in conjunction with one motor. The small hour hand 711 and the small minute hand 712 function as an hour chronograph hand and a minute chronograph hand, that is, hour and minute CG hands in the chronograph mode. The small hour hand 711 is a 12-hours hand and makes one rotation in 12 hours.
Therefore, in the present embodiment, the small hour hand 711 is a first indicating hand, and the small minute hand 712 is a second indicating hand. In addition, the seconds hand 63 that functions as the seconds CG hand in the chronograph mode is a fourth indicating hand that displays the measurement time of seconds or less.
The second small hand 72 is a mode hand that indicates various information. The information indicated by the second small hand 72 can be set as appropriate, but in the present embodiment, the second small hand 72 functions as a mode hand that indicates two modes of the time display mode and the chronograph mode. Specifically, the second small hand 72 functions as a day hand that indicates the day of the week in the time display mode, and functions as a power indicator that indicates that the remaining battery level is low when the remaining battery level is low. The remaining battery level display is also performed when a predetermined button operation is performed. In addition, when the mode is switched to the chronograph mode, the second small hand 72 indicates an indicator indicating the chronograph mode, for example, the character "CHR". When the electronic timepiece 1 has a function of receiving a GPS satellite signal, the second small hand 72 may display the setting of each mode of an airplane mode, which prohibits reception, a time measurement mode, which receives the GPS time information and corrects the internal time, and a position measurement mode, which receives the GPS time information and the orbit information and corrects the internal time and the time zone, in addition to the above functions, or may be used for setting the daytime.
The third small hand 73 is a 1/20 seconds chronograph hand, that is, a 1/20 seconds CG hand, is moved only in the chronograph mode, and is stopped at the 0 seconds position in the time display mode. The third small hand 73 is also a fourth indicating hand like the seconds hand 63 in order to display the measurement time of seconds or less, that is, 1/20 seconds 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 in the afternoon. The fourth small hand 74 is moved in conjunction with the first small hand 71 in the chronograph mode, but there is no particular role.
The hour hand 61, the minute hand 62, the seconds hand 63, the first small hand 71 (small hour hand 711, small minute hand 712), the second small hand 72, the third small hand 73, and the date indicator 50, which are the display section, are driven via a motor and a train wheel which will be described later. The fourth small hand 74 is not driven by an independent motor, and is driven by the motor and the train wheel for driving the first small hand 71 in conjunction with the small hour hand 711 of the first small hand 71, and is a 24-hours hand that makes one rotation in 24 hours. Therefore, the fourth small hand 74 is a third indicating hand that operates in conjunction with the small hour hand 711, which is a first indicating hand, and makes one rotation in 24 hours.
The main portion of the movement 10 built in the exterior case 2 of the electronic timepiece 1 will be described with reference to FIGS. 2 and 3. FIG. 2 is a plan view of a main portion of the movement 10 viewed from a case back side, and FIG. 3 is a plan view of the main portion of the movement 10 viewed from the dial 5 side.
As shown in FIGS. 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 formed of a non-conductive member such as plastic. A plurality of motors and train wheels constituting the drive mechanism 100 are disposed on the case back side of the main plate 15.
As shown in FIGS. 2 and 3, the drive mechanism 100 includes 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 seconds hand 63. Further, the drive mechanism 100 includes a fourth motor 104 and a fourth train wheel 140 that drive the small hour hand 711, the small minute hand 712, which are the first small hand 71, 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. In addition, each train wheel is supported by the main plate 15 and a train wheel bridge (not shown).
The first train wheel 110 includes a first intermediate hour wheel 111, which meshes with a rotor pinion of the first motor 101, a second intermediate hour wheel 112, which meshes with the pinion of the first intermediate hour wheel 111, a third intermediate hour wheel 113, which meshes with the pinion of the second intermediate hour wheel 112, an hour detection wheel 114, and an hour wheel 115, which meshes with the pinion of the third intermediate hour wheel 113. As shown in FIG. 3, the hour detection wheel 114 and the hour wheel 115 are disposed on a front surface side of the main plate 15, that is, on the dial 5 side. The hour hand 61 is attached to a tubular hour hand shaft 610 of the hour wheel 115.
The first intermediate hour wheel 111, the second intermediate hour wheel 112, and the hour detection wheel 114 are formed with holes for detecting the hand position that are detected by a hand position detection device including a light emitting section and a light receiving section used in the related art.
The second train wheel 120 includes a fifth wheel and pinion 121 that meshes with a rotor pinion of the second motor 102, a third wheel and pinion 122 that meshes with a pinion of the fifth wheel and pinion 121, and a center wheel and pinion 123 that meshes with a pinion of the third wheel and pinion 122. The center wheel and pinion 123 is disposed to overlap the hour wheel 115 in a plan view. The minute hand 62 is attached to a tubular minute hand shaft 620 of the center wheel and pinion 123. The fifth wheel and pinion 121, the third wheel and pinion 122, and the center wheel and pinion 123 are formed with holes for detecting the hand position, which are detected by the hand position detection device.
The third train wheel 130 includes an intermediate seconds wheel 131 that meshes with a rotor pinion of the third motor 103, a seconds wheel 132 that meshes with a pinion of the intermediate seconds wheel 131, and a seconds detection wheel 133 that meshes with the pinion of the intermediate seconds wheel 131. The seconds wheel 132 is disposed to overlap the center wheel and pinion 123 and the hour wheel 115 in a plan view. The seconds hand 63 is attached to the seconds hand shaft 630 of the seconds wheel 132. The intermediate seconds wheel 131 and the seconds detection wheel 133 are formed with holes for detecting the hand position, which are detected by the hand position detection device.
Therefore, as shown in FIG. 3, the minute hand shaft 620 is disposed in the tubular hour hand shaft 610, the seconds hand shaft 630 is disposed in the tubular minute hand shaft 620, and the center hand shaft 60 is configured by these. In addition, the hour wheel 115 provided with the hour hand shaft 610, the center wheel and pinion 123 provided with the minute hand shaft 620, and the seconds wheel 132 provided with the seconds hand shaft 630 constitute the center hand wheel.
The fourth train wheel 140 is a train wheel that drives the small hour hand 711 and the small minute hand 712 of the first small hand 71, and includes an HT intermediate wheel 141 that meshes with the rotor pinion of the fourth motor 104, an HT center 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 center 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 the HT center wheel 142 in a plan view, and is disposed on the front surface side of the main plate 15 as shown in FIG. 3.
The first small hand 71 is attached to the 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 center wheel 142. Therefore, the first small hand shaft 710 is configured with the HT hour hand shaft 713 and the HT minute hand shaft 714, and the first small hand wheel is configured with the HT hour wheel 144 and the HT center wheel 142.
The fourth train wheel 140 further has a train wheel provided on the front surface side of the main plate 15 for driving the fourth small hand 74 which is an AM/PM hand (24-hours hand). That is, as shown in FIG. 3, the fourth train wheel 140 includes a first intermediate 24-hours wheel 145 that meshes with the HT hour wheel 144, a second intermediate 24-hours wheel 146 that meshes with the first intermediate 24-hours wheel 145, a third intermediate 24-hours wheel 147 that meshes with the second intermediate 24-hours wheel 146, and a 24-hours wheel 148 that meshes with the pinion of the third intermediate 24-hours wheel 147.
The fourth small hand 74 is attached to the 24-hours hand shaft 740 of the 24-hours wheel 148.
The fifth train wheel 150 is a train wheel that drives the second small hand 72, and as shown in FIG. 2, includes 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 the second small hand shaft 720 to which the second small hand 72 is attached.
The sixth train wheel 160 is a train wheel that drives the third small hand 73, and as shown in FIG. 2, includes 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 FIG. 3, the third small hand wheel 162 has a third small hand shaft 730 to which the third small hand 73 is attached.
The seventh train wheel 170 is a train wheel that drives the date indicator 50, and includes 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 disposed on the front 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 disposed on the front surface side of the main plate 15 and meshes with the pinion of the fourth intermediate wheel 174.
As shown in FIG. 3, the date indicator 50 is a ring-shaped component, an internal tooth is formed in the inner periphery thereof, and the driving wheel 175 meshes with the internal tooth to rotate the date indicator 50. In addition, the center hand shaft 60, the first small hand shaft 710, the second small hand shaft 720, and the third small hand shaft 730 are disposed on the inner peripheral side of the date indicator 50 so as not to interfere with the date indicator 50.
A 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 including a setting lever, a yoke, a click spring, a switch lever, a setting lever spring, a switch contact spring body, a switch contact spring, a switch wheel, and the like in addition to a setting stem 701 to which the crown 3 is attached.
The setting stem 701 is provided at the 3 o'clock position of the dial 5 in a plan view in the movement 10. In addition, the switching device 700 including the setting lever and the like, in addition to the setting stem 701, is disposed along an outer periphery of the dial 5.
In the movement 10, in addition to the above-described configuration, a train wheel bridge (not shown), a printed wired board, a magnetic shield plate, a circuit cover, and the like are disposed on the case back side of the main plate 15. In addition to the above-described configuration, a solar cell (not shown) is disposed on the dial 5 side of the main plate 15 in the movement 10.
FIG. 4 is a block diagram showing a configuration of the electronic timepiece 1. The electronic timepiece 1 includes an input device 11, a time-measuring device 12, a power supply device 13, a control device 20, a storage device 30, a display section 40, and the drive mechanism 100.
The input device 11 is configured to include the above-described crown 3, the button 4A, and the button 4B.
The time-measuring device 12 includes a crystal oscillator or the like driven by power supplied from the power supply device 13, and outputs a clock signal based on an oscillation signal of the crystal oscillator.
The power supply device 13 is a power source of the electronic timepiece 1, and in the present 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 a timepiece, and is configured by coupling a plurality of solar cells in series. The charging circuit supplies the power generated by the solar panel to the secondary battery 14 and charges the secondary battery 14. The power supply device 13 is not limited to the one including the solar panel and the secondary battery 14, and may be any device that can supply power to the control device 20 or the like.
The storage device 30 includes a time data storage section 31, a measurement time storage section 32, a zero return position storage section 33, and a hand position storage section 34. The storage device 30 may be configured in a storage area within an integrated circuit (IC) for a timepiece, or may be configured with an external memory that is externally attached to the integrated circuit (IC) for a timepiece.
The time data storage section 31 stores the time to be displayed by each indicating hand. In the electronic timepiece 1 of the present embodiment, in order to display the time of the local time displayed by the hour hand 61, the minute hand 62, and the seconds hand 63 and the time of the home time displayed by the small hour hand 711 and the small minute hand 712 of the first small hand 71, the time data storage section 31 stores these two types of time data. Therefore, the time data storage section 31 may directly store, for example, two types of time data, that is, time data of the local time and time data of the home time, or may store data that can calculate the two types of time data by storing the coordinated universal time (UTC), the time difference data of the local time, and the time difference data of the home time.
The measurement time storage section 32 stores a time measured in the chronograph mode. In the present embodiment, since the third small hand 73, which is a 1/20 seconds CG hand, is provided, the measurement time storage section 32 stores the time in units of 1/20 seconds in addition to the hour, minute, and seconds of the measurement time.
The zero return position storage section 33 stores whether a zero return position of the first small hand 71 is set to either a first indicating position indicating 0 o'clock or a second indicating position indicating 12 o'clock in the chronograph mode. The zero return position of the first small hand 71 means hand positions of the small hour hand 711 and the small minute hand 712 of the first small hand 71 at the start of measurement in the chronograph mode, that is, a measurement start position.
The small hour hand 711 of the first small hand 71 is a 12-hours system hour hand that makes one rotation in 12 hours, and the indicator indicated by the small hour hand 711 is the same at the first indicating position indicating 0 o'clock and the second indicating position indicating 12 o'clock. On the other hand, the first small hand 71 is managed at a hand position in a 24-hours system from 0:00 to 23:59, as will be described later, and the first indicating position and the second indicating position are managed separately. Furthermore, since the small hour hand 711 and small minute hand 712 of the first small hand 71 are moved in conjunction with each other by the single fourth motor 104, the measurement start position of the first small hand 71, that is, the zero return position, is set in hours and minutes. Therefore, in the zero return position storage section 33, one of the two indicating positions, that is, the first indicating position indicating 0:00 when the small hour hand 711 and the small minute hand 712 overlap each other in the 12 o'clock direction and the second indicating position indicating 12:00 is selected, and is set and stored as the measurement start position, that is, the zero return position of the first small hand 71 in the chronograph mode. In addition, in the zero return position storage section 33, positions that indicate 0 seconds as the measurement start position for the seconds hand 63 which is a seconds CG hand and the third small hand 73 which is a 1/20 seconds CG hand are also stored.
The hand position storage section 34 stores the hand position of each indicating hand. For example, in the hand position storage section 34, a hand position counter is set for each indicating hand driven by each of the motors 101 to 107, the hand position counter updating a count value each time a drive pulse is input to each of the motors 101 to 107 and resetting the count value when a reference position is detected by the hand position detection device.
For example, the hand position counter for the first small hand 71 driven by the fourth motor 104 is configured to be an up-down counter that can count 60 minutes × 24 hours = 1440 count values because the fourth motor 104 drives the small hour hand 711 and the small minute hand 712 in a forward direction and a reverse direction. Therefore, the hand position counter for the first small hand 71 is configured to count from "0" to "1339", and it is set such that the counter value "0" represents the first indicating position where the first small hand 71 indicates 0:00, the counter value "720" represents the second indicating position where the first small hand 71 indicates 12:00, and the counter value "1339" represents the position where the first small hand 71 indicates 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 a drive control section 25, which will be 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 section 25 to the fourth motor 104. In addition, when the drive pulse for the forward rotation is input from the drive control section 25 to the fourth motor 104 at the counter value "1339" to count up, the counter value returns to "0". The hand position counter for the other indicating hands is also set in the same manner according to each indicating hand.
The control device 20 is configured with an integrated circuit (IC) for a timepiece that controls the electronic timepiece 1. A display control section of the present embodiment is configured by the control device 20.
The control device 20 includes an input detection section 21, a display time control section 22, a chronograph control section 23, a mode hand control section 24, and the drive control section 25.
The input detection section 21 detects an input operation of the input device 11, and in the present embodiment, detects a pulling-out position, a rotation direction, and the number of rotations of the crown 3 and the operation of pressing and releasing the buttons 4A and 4B.
The display time control section 22 updates the time data of the time data storage section 31 by using the clock signal output from the time-measuring device 12. In addition, the display time control section 22 drives the drive mechanism 100 via the drive control section 25 in conjunction with the update of the time data storage section 31, and drives the hour hand 61, the minute hand 62, the seconds hand 63, the first small hand 71 and the fourth small hand 74, the second small hand 72, and the date indicator 50 of the display section 40.
The chronograph control section 23 executes a time measurement process by using the clock signal output from the time-measuring device 12 in the chronograph mode, stores the measurement time in the measurement time storage section 32, and controls the driving of the third small hand 73, the seconds hand 63, and the first small hand 71 used as the chronograph hand via the drive control section 25.
The mode hand control section 24 controls the driving of the second small hand 72 via the drive control section 25.
The drive control section 25 outputs a drive pulse to each of the motors 101 to 107 and controls the driving of each of the motors 101 to 107.

Switching Control to Chronograph Mode

Next, switching control in the control device 20 which is the display control section of the electronic timepiece 1 when a mode switching operation to the chronograph mode is performed by a first operation section will be described. The mode switching operation is set as appropriate according to the input device 11 of the electronic timepiece 1, but in the present embodiment, in the time display mode, the mode is switched from the time display mode to the chronograph mode by pulling out the crown 3 by one stage and pressing and releasing the button 4B to push back the crown 3 in a state where the second small hand 72 indicates the indicator "CHR" that indicates the chronograph mode. In addition, in the chronograph mode, the chronograph mode is released and the mode is switched to the time display mode by pulling out and pushing back the crown 3. Therefore, in the present embodiment, the first operation section that performs the mode switching operation between the time display mode and the chronograph mode is configured to include the crown 3 and the button 4B. In addition, the switching to the chronograph mode may be performed by directly switching from the time display mode to the chronograph mode, or may be performed by switching from a mode other than the time display mode, such as a time zone selection mode, to the chronograph mode.
When the input detection section 21 of the control device 20 detects the switching operation to the chronograph mode by the input device 11, the chronograph control section 23 executes the zero return process of moving the third small hand 73, the seconds hand 63, the small hour hand 711, and the small minute hand 712 used as the chronograph hands to the measurement start position.
The third small hand 73 which is a 1/20 seconds CG hand which is a sub-second CG hand is not used in the time display mode, and thus is stopped at the 0 seconds position which is the zero return position. Therefore, when the zero return process is started, it is not necessary to move the third small hand 73, but in the present embodiment, the chronograph control section 23 performs a process of causing the third small hand 73 to make one rotation in the forward direction by fast forwarding and to move to the 0 seconds position which is the zero return position. As a result, the user can easily recognize that the mode is switched to the chronograph mode by the third small hand 73 that does not move in the time display mode moving one rotation by the fast forwarding. The third small hand 73, which is a 1/20 seconds CG hand, makes one rotation in one second during the time measurement, so the time required to make one rotation by fast forwarding and to move to the zero return position can be set to less than one second, for example, 0.7 seconds.
The chronograph control section 23 starts the zero return process of the seconds hand 63, which is the seconds CG hand, at the same time as the start of the zero return process of the third small hand 73. In the present embodiment, the seconds hand 63, which also serves as the seconds CG hand, is used as the seconds hand in the time display mode, so the process of moving the hand in the forward direction by the fast forwarding from the hand position indicating the seconds of the current time to the 0 seconds position, which is the zero return position, is started. The maximum time required for moving the seconds hand 63 to the zero return position in the forward direction by the fast forwarding is a time until the seconds hand 63 moves to the 0 seconds position which is the zero return position, by fast forwarding 59 seconds in the forward direction from a position indicating the indicator of 1 second, and is, for example, 0.9 seconds.
Therefore, after switching to the chronograph mode, the zero return process of the seconds hand 63 and the third small hand 73 is completed in less than 1 second. The seconds hand 63 and the third small hand 73 are fast-forwarded in the forward direction, because the third motor 103 and the sixth motor 106 that drive these include a motor having one coil, and the fast forward speed in the forward direction is faster than the fast forward speed in the reverse direction. Therefore, the seconds hand 63 and the third small hand 73 are both returned to zero by fast forwarding in the forward direction.
The chronograph control section 23 starts the zero return process of the first small hand 71, which is a sub-dial, at the same time as the start of the zero return process of the seconds hand 63 and the third small hand 73. The zero return process of the first small hand 71, which is the sub-dial, will be described with reference to the flowchart of FIG. 5. The zero return process of the first small hand 71 of the present embodiment is based on the prerequisite that the fourth motor 104 that drives the first small hand 71 has two coils and the fast forward frequency in the forward direction and the reverse direction, that is, the fast forward speed in the forward direction and the reverse direction are the same. In addition, as described above, the hand position of the first small hand 71 is managed by the hand position counter value of "0" to "1339".
First, the chronograph control section 23 acquires a 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 the small minute hand 712 that display the home time in the time display mode (Step S1). Since the current hand position of the first small hand 71 is stored in the hand position storage section 34, the chronograph control section 23 acquires the hand position of the first small hand 71 by detecting a value of the hand position counter for the first small hand 71 in the hand position storage section 34.
Next, the chronograph control section 23 determines whether or not 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 section 23 determines whether or not 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.
When the determination result is YES in Step S2, the chronograph control section 23 sets the zero return position, that is, the measurement start position, to 12:00, which is the second indicating position (Step S3). Then, the chronograph control section 23 determines whether or not the current hand position is equal to or less than 12:00 (Step S4). When the determination result is YES in Step S4, the chronograph control section 23 sets the rotation direction to the forward rotation (Step S5), and when the determination result is NO in Step S4, the chronograph control section 23 sets the rotation direction to the reverse rotation (Step S6).
When the determination result is NO in Step S2, the chronograph control section 23 sets the zero return position, that is, the measurement start position to 0:00, which is the first indicating position (Step S7). Then, the chronograph control section 23 determines whether or not the current hand position is equal to or greater than 18:00 or 0:00 (Step S8). When the determination result is YES in Step S8, the chronograph control section 23 sets the rotation direction to the forward rotation (Step S9), and when the determination result is NO in Step S8, the chronograph control section 23 sets the rotation direction to the reverse rotation (Step S10).
Next, the chronograph control section 23 stores and updates the zero return position, that is, the measurement start position set in steps S3 and S7 in the zero return position storage section 33 (Step S11).
Next, the chronograph control section 23 calculates the hand movement amount, that is, the number of drive pulses of the fourth motor 104, based on the zero return position and the rotation direction set from the current hand position of the first small hand 71 (Step S12).
Then, the chronograph control section 23 performs the hand movement of the first small hand 71, which is the sub-dial, to the zero return position based on the set rotation direction and hand movement amount (Step S13).
Through the above-described zero return process, the first small hand 71 is returned to the measurement start position which is the indicating position having a short movement time between the first small hand 71, that is, the small hour hand 711, which is the first indicating hand, and the small minute hand 712, which is the second indicating hand among the first indicating position (0:00) or the second indicating position (12:00), as the zero return position which is the measurement start position. For example, when the current time of the home time displayed by the first small hand 71 is 17:05, and the switching operation to the chronograph mode is performed, the determination result is YES in Step S2, and the zero return position is set to 12:00, which is the second indicating position in Step S3, the determination result is NO in Step S4, and the rotation direction is set to reverse in Step S6. In Step S11, the chronograph control section 23 updates the zero return position to 12:00, which is the second indicating position, in Step S12, calculates the hand movement amount as 5 hours and 5 minutes based on the relationship between 17:05, which is the current hand position, and the zero return position, and in Step S13, causes the fourth motor 104 to perform the hand movement for 5 hours and 5 minutes in reverse rotation through the drive control section 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 in reverse rotation to a downward position indicating 12 o'clock.
As described above, the zero return position of the first small hand 71 can be selected from the first indicating position (0:00) and the second indicating position (12:00), and the fast forward speed in both the forward and reverse directions by the fourth motor 104 is the same. Therefore, the time required for the first small hand 71 to be moved to the measurement start position (zero return position) when switching to the chronograph mode can be minimized. That is, the first small hand 71, which is a sub-dial, has the zero return position at the first indicating position or the second indicating position, and can be fast-forwarded at the same speed in both the forward and reverse directions. Therefore, the first small hand 71 can be moved to the zero return position by the maximum of six hours of movement. In the present embodiment, the maximum time required for the small hour hand 711 and the small minute hand 712, which are moved by the fourth motor 104, are returned to the zero return position by fast forwarding is 3.5 seconds.

Time Measurement Control in Chronograph Mode

After the switching to the chronograph mode, when the input detection section 21 detects that the button operation for starting the time measurement is performed, the chronograph control section 23 starts the time measurement. In the present embodiment, pressing the button 4A starts the time measurement. Therefore, the button 4A is a third operation section that instructs the start of measurement in the chronograph mode.
In the present embodiment, the condition for permitting the button operation to start time measurement is that, when the seconds CG hand and the sub-second CG hand used in the chronograph have completed moving to the zero return position, even before the first small hand 71 of the sub-dial has returned to zero, the button operation to start time measurement is permitted when the seconds hand 63, which is the seconds CG hand, and the third small hand 73, which is the 1/20 seconds CG hand, move to the zero return position, that is, the 0 seconds position, and time measurement is started. As described above, the maximum time required for the seconds hand 63 to be moved to the zero return position is 0.9 seconds, and the time required for the third small hand 73 to make one rotation is 0.7 seconds. Therefore, when the maximum 0.9 seconds have elapsed until the seconds hand 63 and the third small hand 73 return to the zero return position after the user switches to the chronograph mode, the button operation for starting the time measurement is permitted, and the time measurement can be started even before the first small hand 71 returns to the zero return position.
In the related art, as a condition for permitting the button operation for starting the time measurement, the following two patterns are known.
A first pattern enables the measurement to be started even during the movement or the return to zero of any of the indicating hands used for the chronograph. The advantage of the first pattern is that the measurement can be performed immediately without the user waiting for the preparation of the chronograph mode, and the disadvantage is that the operation can be performed while the hand is operating, and thus it is difficult to grasp what the indicating hand is displaying.
A second pattern enables the measurement to be started after all the indicating hands used for the chronograph move to the zero return position. The advantage of the second pattern is that it is clear that the chronograph mode is switched, and it is easy to understand and erroneous operation is less likely to occur, and the disadvantage is that it takes a longer time to wait until the indicating hand moves to the zero return position.
On the other hand, the pattern of the present embodiment starts the time measurement between the first pattern and the second pattern, and enables the measurement when the movement of the third small hand 73, which is the sub-second CG hand used for the chronograph, and the seconds hand 63, which is the seconds CG hand, to the zero return position is completed. Therefore, the advantage and disadvantage of the pattern of the present embodiment are intermediate between the first and second patterns. That is, the reason for selecting the seconds hand 63 and the third small hand 73 as the hands that complete the movement before the measurement operation becomes possible is that the first small hand 71, which is a sub-dial, takes more time to return to zero than the other hands. Therefore, when waiting for the first small hand 71 to complete the movement, there is a large disadvantage that the measurement cannot be performed immediately after the mode is switched. On the other hand, regarding the seconds hand 63 and the third small hand 73, which are hands of seconds or less, the user cannot easily grasp whether the measurement is started without starting the measurement from the zero return position, and on the other hand, the movement time is also shorter than that of the first small hand 71, which is a sub-dial, and thus the disadvantage of the waiting time is small. Since the first small hand 71, which is a sub-dial, represents the minute and the hour of the measurement time, the first small hand 71 is not used to display the measurement time until the measurement time elapses for one minute. Therefore, even though the first small hand 71 that returns to zero in about 3.5 seconds is moved to return to zero immediately after the time measurement starts, the user gazes at the seconds hand 63 and the third small hand 73, so the influence is small even though the time measurement starts before the first small hand 71 returns to zero.
In the present embodiment, as a chronograph indicating hand, a sub-second CG hand indicating less than a second (for example, 1/100 seconds or 1/20 seconds) is mounted, and when the sub-second CG hand is operating and at the start of the operation, the fast forwarding of the other indicating hands and the date indicator 50 is stopped. For example, when the local time becomes 0:00 AM and the fast forwarding of the date indicator 50 is necessary on a daily basis to change the date display, the fast forwarding of the date indicator 50 is started after the sub-second CG hand is stopped when the sub-second CG hand is operating. In addition, when the measurement of the chronograph is started by an operation while the date indicator 50 is fast forwarding on a daily basis and the sub-second CG hand operates, the date indicator 50 is stopped even in the middle of its movement. In another case, when the automatic reception by the reception function of the GPS satellite signal operates during the time measurement, the hour hand 61, the minute hand 62, and the date indicator 50 may be fast-forwarded. In this case as well, the fast forwarding of the other indicating hands is started after the sub-second CG hand is stopped in order to prioritize the operation of the sub-second CG hand.
The reason why such control is performed is that when the operation of the sub-second CG hand is controlled by the software while maintaining low power consumption, the processing load is extremely high, and when other operations are performed in parallel, the processing time is delayed, and the sub-second CG hand is difficult to operate in accordance with the actual measurement time. Therefore, as in the present embodiment, when the third small hand 73, which is a 1/20 seconds CG hand, operates, the processing load can be reduced by stopping the fast forwarding of the other indicating hands.
When the mode is switched to the chronograph mode and the seconds hand 63 and the third small hand 73 return to the 0 seconds position, which is the zero return position, the chronograph control section 23 receives the operation of starting the time measurement through the button 4A. Therefore, when the input detection section 21 detects that the button 4A is pressed, the chronograph control section 23 starts time measurement and moves the third small hand 73, the seconds hand 63, and the first small hand 71. The third small hand 73, which is the 1/20 seconds CG hand, operates only for a maximum of 1 minute from the start of time measurement, and then stops at the 0 seconds position in order to reduce the load of the time measurement process. When the split operation or the stop operation to be described later is performed, the seconds hand 63 and the first small hand 71 stop at a position where the measurement time at the time of the operation is displayed, and the third small hand 73 displays the seconds at the time of the operation.
When the button 4A is pressed during the time measurement, the chronograph control section 23 stops the time measurement, and stops the movement of the third small hand 73, the seconds hand 63, and the first small hand 71. When the button 4A is pressed while the time measurement is stopped, the chronograph control section 23 restarts the time measurement. Even when the time measurement is restarted, the third small hand 73 operates only for 1 minute.
When the measurement time of the chronograph is 12 hours, that is, when the small hour hand 711 of the first small hand 71 moves one rotation and returns to the zero return position, the chronograph control section 23 automatically stops the time measurement.
When the button 4B is pressed while the time measurement is stopped, the time is reset, and the third small hand 73, the seconds hand 63, and the first small hand 71 are returned to the zero return position in the same manner as when switching to the chronograph mode shown in FIG. 5. Therefore, the button 4B is the second operation section through which the reset operation is performed.
For example, when the zero return position at the time of transition to the chronograph mode is 0:00, the hand position of the first small hand 71 immediately before the reset is 9:00 because the chronograph measurement is performed for 9 hours and then the reset operation is performed with the button 4B. Therefore, in the flowchart shown in FIG. 5, the determination result is YES in Step S2, the determination result is YES in Step S4, the first small hand 71 is moved in the forward rotation to the 12:00 position, and the new zero return position is updated to 12:00.
Subsequently, when the chronograph measurement is started by pressing the button 4A, and the reset operation is performed with the button 4B after 5 hours of measurement, the hand position of the first small hand 71 immediately before the reset is 17:00. Therefore, in the flowchart of FIG. 5, it is determined as YES in Step S2, it is determined as NO in Step S4, the first small hand 71 is moved in the reverse rotation to the 12:00 position, and the new zero return position is updated to 12:00.
Therefore, the zero return position of the first small hand 71 stored in the zero return position storage section 33 of the storage device 30 is updated when the mode is switched to the chronograph mode and when the time measurement in the chronograph mode is reset. The zero return position of the first small hand 71 stored in the zero return position storage section 33 is used when there is a deviation between the time measured by the chronograph and the display position of the hand, such as when releasing the split as described below or when restarting the chronograph hand while the chronograph hand is returned to zero.
When the chronograph mode is reset and restarted, the measurement is started even though all the chronograph hands are not returned to zero. That is, the operation of the indicating hand when the start instruction is given before the chronograph hand returns to the zero return position is as follows.
The third small hand 73, which is a 1/20 seconds chronograph hand, is fast-forwarded in the forward direction and returned to zero, but when there is a start instruction before returning to the zero return position, the third small hand 73 fast-forwards until catching up with the display of the measurement time without stopping at the 0 seconds position, which is the zero return position. When the hand position of the third small hand 73 catches up with the measurement time, the third small hand 73 starts the movement of the 1/20 seconds movement. The forward fast forward frequency of the third small hand 73 is, for example, 85.3 Hz. In the present embodiment, since the third small hand 73 makes one rotation by inputting 60 drive pulses to the sixth motor 106, theoretically, the third small hand 73 can catch up with the display position of the measurement time as long as the fast forward frequency is 60 Hz or more.
The seconds hand 63, which is a seconds CG hand, is fast-forwarded in the forward direction and returned to zero, but when there is a start instruction before returning to the zero return position, the seconds hand 63 fast-forwards until catching up with the display of the measurement time without stopping at the 0 seconds position, which is the zero return position, when the measurement time is already 1 second or more, similar to the operation of the third small hand 73.
As described above, the first small hand 71 of the sub-dial, which is hour and minute CG hands, moves to the zero return position set by the hand position of the first small hand 71 immediately before the reset by the fast forwarding and stops. That is, since the first small hand 71 returns to zero in a maximum of about 3.5 seconds, the first small hand 71 stops at the zero return position until the measurement time elapses for 1 minute and the first small hand 71 starts to move.

Split Measurement Control

The split measurement is a measurement method in which the time measurement of the chronograph is continued, and only the display of the chronograph hand is stopped to read a split time, which is the elapsed time from the start.
To perform the split measurement, similar to normal chronograph time measurement, when the button 4A is pressed after switching to the chronograph mode, the chronograph control section 23 starts chronograph measurement as shown in FIG. 6 (Step S21). Therefore, the seconds hand 63, the third small hand 73, and the first small hand 71, which are the chronograph hands, are in a movement state (Step S22).
The chronograph control section 23 determines whether or not the button 4B is pressed and the split operation is performed during the movement of the chronograph hand in Step S22 (Step S23). When the determination result is NO in Step S23, the chronograph control section 23 continues the movement state of the chronograph hand in Step S22, that is, the time measurement state.
On the other hand, when the determination result in Step S23 is YES, that is, when the button 4B is pressed, the chronograph control section 23 stops the chronograph hand in a split display (Step S24). At this time, the chronograph control section 23 continues the time measurement, that is, updating the measurement time stored in the measurement time storage section 32.
The chronograph control section 23 determines whether or not the button 4B is pressed and the split release operation is performed during the stop in the split display in Step S24 (Step S25). When the determination result is NO in Step S25, the chronograph control section 23 maintains the state where the chronograph hand is stopped in the split display in Step S24, and continues updating the measurement time of the measurement time storage section 32.
On the other hand, when the determination result is YES in Step S25, that is, when the button 4B is pressed and the split release operation is performed, the chronograph control section 23 executes the process of Step S30 of moving the chronograph hand to the measurement time by fast forwarding.
The process of Step S30 is shown in the flowchart of FIG. 7. The chronograph control section 23 refers to the measurement time storage section 32 and acquires the chronograph measurement time (Step S31). In addition, the chronograph control section 23 refers to the zero return position storage section 33, and determines whether or not the zero return position is 0:00, which is the first indicating position (Step S32).
When the determination result is NO in Step S32, that is, when the zero return position is 12:00, the chronograph control section 23 adds 12 hours to the chronograph measurement time for the hand position conversion (Step S33). That is, since the hand position of the first small hand 71 stored in the hand position storage section 34 is in the 24-hours system, when the zero return position is 12:00, and the chronograph measurement time is 1 hour, the hand position indicated by the first small hand 71 is 13:00, that is, the hand position counter needs to be set to "780". Therefore, by adding the offset amount of 12 hours to the chronograph measurement time, the hand position of the first small hand 71 can be converted to the 24-hours system. The process of Step S33 is only for obtaining the hand position of the first small hand 71, and the measurement time stored in the measurement time storage section 32 is continuously updated by the clock signal.
When the determination result is YES in Step S32, or after the offset process of Step S33 is performed, the chronograph control section 23 executes the conversion to the hand positions of the first small hand 71, the seconds hand 63, and the third small hand 73 based on the chronograph measurement time (Step S34). In Step S34, the chronograph control section 23 converts the hour and minute data of the chronograph measurement time set according to the zero return position into the hand position of the first small hand 71. In addition, the chronograph control section 23 converts the data of the seconds and the sub-second (1/20 seconds) of the chronograph measurement time into the hand positions of the seconds hand 63 and the third small hand 73. Since the zero return positions of the seconds hand 63 and the third small hand 73 are always 0 seconds, the offset conversion is not necessary.
Next, the chronograph control section 23 calculates the movement amount to the hand position converted in Step S34 from the hand positions of the first small hand 71, the seconds hand 63, and the third small hand 73, which are stopped by the split, that is, the hand positions stored in the hand position storage section 34 (Step S35). The chronograph control section 23 controls the fourth motor 104, the third motor 103, and the sixth motor 106 via the drive control section 25, and starts the fast forwarding the first small hand 71, the seconds hand 63, and the third small hand 73 in the forward direction by the calculated movement amount in Step S35 (step S36). By fast forwarding in Step S36, the first small hand 71, the seconds hand 63, and the third small hand 73, which are chronograph hands, are moved by fast forwarding from the position where they are stopped during the split to the position where the current chronograph measurement time is indicated when the split is released.
When the process of Step S30 shown in FIG. 7 is completed, the movement state of the chronograph hand is continued as shown in FIG. 6 (Step S26). When the button 4B is pressed while the chronograph hand is in a continuous movement state, a split display is performed, and then, when the button 4B is pressed again, the split is released. When the button 4A is pressed in the movement state of the chronograph hand, the chronograph measurement is stopped, and when the button 4B is pressed in this stopped state, the chronograph measurement time is reset, and each chronograph hand is returned to zero. Switching Control to Time Display Mode
Next, control when releasing the chronograph mode and switching to the time display mode will be described. The operation of releasing the chronograph mode can be set as appropriate, but in the present embodiment, as described above, the chronograph mode is released by pulling out and pushing back the crown 3, and the mode is switched to the time display mode. At this time, the second small hand 72 switches to the display of the time display mode, for example, the day of the week display. In addition, since the hour hand 61 and the minute hand 62 continue to display the local time even in the chronograph mode, the time display continues even after the chronograph mode is released. Meanwhile, the display time control section 22 switches the seconds hand 63 to the seconds display of the current time, and the third small hand 73 moves to the zero return position, that is, the 0 seconds position.
Further, the display time control section 22 moves the first small hand 71 of the sub-dial to the current time position. The movement control of the first small hand 71 will be described with reference to a flowchart of FIG. 8.
When the chronograph mode is released, the display time control section 22 acquires a hand position A of the first small hand 71, which is the sub-dial, at the time of releasing the chronograph mode, from the hand position storage section 34 (Step S41).
Next, the display time control section 22 acquires the current time of the first small hand 71, which is the sub-dial, from the time data storage section 31 (Step S42). Next, the display time control section 22 acquires a hand position B of the current sub-dial time, that is, the hand position B indicating the home time (Step S43).
The display time control section 22 determines whether or not a difference between the hand position B and the hand position A is less than 12 hours (Step S44), sets the rotation direction to the forward rotation when the determination result is YES in Step S44 (Step S45), and sets the rotation direction to the reverse rotation when the determination result is NO in Step S44 (Step S46).
Next, the display time control section 22 calculates the movement amount 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 movement amount (Step S48).
For example, when the zero return position in the chronograph mode is 12:00, which is the second indicating position, and the chronograph mode is released after one hour of measurement, the hand position A of the first small hand 71 is a position indicating 13:00. On the other hand, it is assumed that the current time indicated by the first small hand 71, that is, the hand position B of the home time is 3:15. Since a hand position B-A is calculated as a time required for the hand to reach the hand position B when the hand is rotated in the forward direction from the hand position A, by regarding the hand position B as 24 hours + 3 hours and 15 minutes, the hand position B-A becomes 14 hours and 15 minutes, and it is determined to be 12 hours or more. Therefore, a rotation direction is set to the reverse direction, and the amount of hand movement in the reverse direction from the hand position A at 13:00 to the hand position B at 3:15 is 9 hours and 45 minutes. Therefore, the first small hand 71 is moved in the reverse direction for 9 hours and 45 minutes by fast forwarding.
As described above, the mode is switched to the time display mode, and the hour hand 61, the minute hand 62, and the seconds hand 63 display the hour, minute, and seconds of the local time, the first small hand 71 displays the hour and minute of the home time, the fourth small hand 74 displays the morning or the afternoon of the home time, and the third small hand 73 stops at the zero return position, that is, the 0 seconds position.

Effects of Embodiment

In the present embodiment, at the timing of transitioning to the chronograph mode or the timing of resetting the measurement display, based on the display time and the measurement time of the first small hand 71, an indicating position having a shorter movement time of the first small hand 71 among the two indicating positions of the first indicating position or the second indicating position can be set as the zero return position to start the movement of the hand for zero return. Therefore, when the zero return position at the start of measurement in the chronograph mode is always set to 0:00, which is the first indicating position, the maximum movement amount of the first small hand 71 is 12 hours, but compared to this, the maximum movement amount of the first small hand 71 to the zero return position can be halved to 6 hours, and the movement time can be shortened. Therefore, the time for the user to recognize the display at the time of mode switching and the measurement time and to wait for operation can be shortened, and the operability and convenience of the user can be improved. In addition, the same effect can also be obtained even when the chronograph reset operation is performed after the chronograph measurement is performed.
Since the zero return position storage section 33 for storing the zero return position of the first small hand 71 each time it is updated is provided, when the display time is matched to the measurement time from a state in which the display time and the measurement time of the first small hand 71 are deviated, such as when the split is released, the movement amount for fast forwarding the first small hand 71 can be easily calculated by using the zero return position stored in the zero return position storage section 33 and the measurement time stored in the measurement time storage section 32, and the fast-forward process can be easily executed. That is, when the zero return position is not stored, in order to calculate a position at the time of split release, it is necessary to count the time from the start of the split to the release of the split and to calculate the display position by adding the counted time to the hand position, and it is necessary to use an additional storage area or a timer for time measurement, resulting in a large amount of resources. On the other hand, as in the present embodiment, when the zero return position storage section 33 is provided, the need to separately count the time from the start of the split to the release of the split can be eliminated.

Modification Example

The first indicating hand that serves as the hour CG hand in the chronograph mode is not limited to the small hour hand 711 of the sub-dial, and the hour hand 61 may be used as the first indicating hand. Since the hour hand 61 also displays the time in the 12-hours system, the measurement start position (zero return position) may be selected from the first indicating position indicating 0 o'clock or the second indicating position indicating 12 o'clock. The second indicating hand that serves as the minute CG hand in the chronograph mode is not limited to the small minute hand 712, and the minute hand 62 may be used as the second indicating hand. In this case, since the minute hand 62 that serves as the minute CG hand is independently moved by the second motor 102, the measurement start position thereof can be fixed to the position indicating 0 minutes.
As a motor that drives the first indicating hand that serves as the hour CG hand in the chronograph mode, the fourth motor 104 having two coils having the same fast forward speed in the forward direction and the reverse direction is used, but a motor having a different fast forward speed in each direction may be used. In this case, it is necessary to set a time of a threshold for selecting the first indicating position and the second indicating position, which are the zero return positions, that is, the time of the hand position determination in Steps S2, S4, and S8 in FIG. 5, such that the shorter movement time is selected in consideration of the difference between the fast forward speeds in the forward direction and the reverse direction. Summary
An electronic timepiece of the present disclosure having at least two modes of a time display mode and a chronograph mode, includes a first operation section configured to perform a mode switching operation for switching the mode, a first indicating hand configured to display an hour of a time in a 12-hours system in the time display mode and display an hour of a measurement time in the chronograph mode, and a display control section configured to move the first indicating hand to a measurement start position in the chronograph mode by fast forwarding based on the mode switching operation for switching to the chronograph mode, in which the display control section is configured to distinguish and manage two indicating positions of a first indicating position at which the first indicating hand indicates 0 o'clock and of a second indicating position at which the first indicating hand indicates 12 o'clock in the time display mode, and set, when switching to the chronograph mode, an indicating position having a shorter movement time of the first indicating hand among the two indicating positions to the measurement start position, based on a display time of the first indicating hand at a time of the switching operation, and move the first indicating hand to the set measurement start position.
According to the electronic timepiece of the present disclosure, the display control section is configured to select and set the measurement start position in the chronograph mode from two indicating positions, which are the first indicating position indicating 0 o'clock and the second indicating position indicating 12 o'clock. Therefore, based on the display time of the first indicating hand at the time of mode switching to the chronograph mode, the measurement start position having a shorter movement time of the first indicating hand from the two indicating positions can be selected. Therefore, the time for moving the first indicating hand to the measurement start position can be shortened as compared with a case where the measurement start position in the chronograph mode is always set to the first indicating position indicating 0 o'clock.
In the electronic timepiece according to the present disclosure, it is preferable that a second operation section configured to perform a reset operation for resetting a time measurement in the chronograph mode is further provided and when the reset operation is performed, the display control section is configured to set the indicating position having a shorter movement time of the first indicating hand among the two indicating positions to the measurement start position, based on a hand position of the first indicating hand, and move the first indicating hand to the set measurement start position.
According to the electronic timepiece of the present disclosure, even at the time of the reset operation, the display control section can set and move the measurement start position having the shorter movement time for the first indicating hand from the two indicating positions based on the current hand position of the first indicating hand. Therefore, even at the time of reset, the time for moving the first indicating hand to the measurement start position can be shortened.
In the electronic timepiece according to the present disclosure, it is preferable that a second indicating hand configured to operate in conjunction with the first indicating hand and display minutes is further provided, and the display control section is configured to manage a position at which the first indicating hand and the second indicating hand indicate 0:00 as the first indicating position and a position at which the first indicating hand and the second indicating hand indicate 12:00 as the second indicating position, and set, when switching to the chronograph mode, an indicating position having a shorter movement time of the first indicating hand and the second indicating hand among the two indicating positions to the measurement start position, based on display times of the first indicating hand and the second indicating hand at the time of the switching operation, and move the first indicating hand and the second indicating hand to the set measurement start position.
According to the electronic timepiece of the present disclosure, the first indicating hand and the second indicating hand operate in conjunction with each other, and thus can be driven by one motor. Therefore, the measurement start position at the time of mode switching can be selected from the first indicating position indicating 0:00 and the second indicating position indicating 12:00, and thus the time for moving the first indicating hand and the second indicating hand to the measurement start position can be shortened as compared with a case where the measurement start position is always set to the first indicating position.
In the electronic timepiece according to the present disclosure, it is preferable that a third indicating hand configured to operate in conjunction with the first indicating hand and make one rotation in 24 hours is further provided.
According to the electronic timepiece of the present disclosure, since the third indicating hand that is in conjunction with the first indicating hand and makes one rotation in 24 hours is provided, the user can easily confirm whether the first indicating hand is displaying the time in the morning or the time in the afternoon.
In the electronic timepiece according to the present disclosure, it is preferable that a motor configured to drive the first indicating hand is further provided, and the motor includes two coils and is configured to drive the first indicating hand in a forward direction and a reverse direction at the same speed.
According to the electronic timepiece of the present disclosure, the motor that drives the first indicating hand includes two coils, and the first indicating hand can be driven at the same speed in the forward direction and the reverse direction. Therefore, the movement time of the first indicating hand to the measurement start position can be minimized.
In the electronic timepiece according to the present disclosure, it is preferable that a fourth indicating hand configured to display a measurement time of seconds or less and set to have a position indicating 0 seconds as the measurement start position in the chronograph mode; and a third operation section configured to instruct a measurement start in the chronograph mode are further provided, the display control section is configured to move the fourth indicating hand to the measurement start position by fast forwarding based on the mode switching operation for switching to the chronograph mode, and the display control section is configured to receive the instruction of the measurement start from the third operation section after the fourth indicating hand moves to the measurement start position and start a time measurement of a chronograph.
According to the electronic timepiece of the present disclosure, when switching to the chronograph mode, the fourth indicating hand moves to the measurement start position where the fourth indicating hand indicates 0 seconds by the fast forwarding. Therefore, the user can easily confirm that the chronograph mode is switched. In addition, since the fourth indicating hand displays the measurement time of seconds or less of the chronograph, the time for moving to the measurement start position by the fast forwarding is also a short time, and the measurement of the chronograph can be started when the fourth indicating hand moves to the measurement start position. Therefore, the time measurement in the chronograph mode can be started before the first indicating hand moves to the measurement start position, and the waiting time until the measurement start can be shortened.
In the electronic timepiece according to the present disclosure, it is preferable that an upper limit time measurable in the chronograph mode is 12 hours.
According to the electronic timepiece of the present disclosure, since the upper limit time that can be measured in the chronograph mode is 12 hours, the first indicating hand of the 12-hours system moves only one rotation from the measurement start position in the chronograph mode. Therefore, the user can easily confirm the measurement time.
In the electronic timepiece according to the present disclosure, it is preferable that a storage section configured to store a time in the time display mode, the measurement time in the chronograph mode, and a hand position of the first indicating hand is further provided. According to the electronic timepiece of the present disclosure, the storage section that stores the time in the time display mode, the measurement time in the chronograph mode, and the hand position of the first indicating hand is provided. Therefore, when switching between the time display mode and the chronograph mode in the mode switching operation, the time and the measurement time can be easily switched and displayed with the first indicating hand.
In the electronic timepiece according to the present disclosure, it is preferable that the storage section stores the set measurement start position.
According to the electronic timepiece of the present disclosure, since the storage section stores the measurement start position set by the display control section, when the measurement time and the time indicated by the chronograph hand deviate from each other during the split operation or the like, a process of fast forwarding the chronograph hand to the measurement time at the time of split release can be easily performed.

Claims

An electronic timepiece having at least two modes of a time display mode and a chronograph mode, the electronic timepiece comprising:
a first operation section configured to perform a mode switching operation for switching the mode;

a first indicating hand configured to display an hour of a time in a 12-hours system in the time display mode and display an hour of a measurement time in the chronograph mode; and

a display control section configured to move the first indicating hand to a measurement start position in the chronograph mode by fast forwarding based on the mode switching operation for switching to the chronograph mode, wherein

the display control section is configured to
distinguish and manage two indicating positions of a first indicating position at which the first indicating hand indicates 0 o'clock and of a second indicating position at which the first indicating hand indicates 12 o'clock in the time display mode, and

set, when switching to the chronograph mode, an indicating position having a shorter movement time of the first indicating hand among the two indicating positions to the measurement start position, based on a display time of the first indicating hand at a time of the switching operation, and move the first indicating hand to the set measurement start position.
The electronic timepiece according to claim 1, further comprising:
a second operation section configured to perform a reset operation for resetting a time measurement in the chronograph mode, wherein

when the reset operation is performed, the display control section is configured to set the indicating position having a shorter movement time of the first indicating hand among the two indicating positions to the measurement start position, based on a hand position of the first indicating hand, and move the first indicating hand to the set measurement start position.
The electronic timepiece according to claim 1, further comprising:
a second indicating hand configured to operate in conjunction with the first indicating hand and display minutes, wherein

the display control section is configured to
manage a position at which the first indicating hand and the second indicating hand indicate 0:00 as the first indicating position and a position at which the first indicating hand and the second indicating hand indicate 12:00 as the second indicating position, and

set, when switching to the chronograph mode, an indicating position having a shorter movement time of the first indicating hand and the second indicating hand among the two indicating positions to the measurement start position, based on display times of the first indicating hand and the second indicating hand at the time of the switching operation, and move the first indicating hand and the second indicating hand to the set measurement start position.
The electronic timepiece according to claim 1, further comprising:
a third indicating hand configured to operate in conjunction with the first indicating hand and make one rotation in 24 hours.
The electronic timepiece according to claim 1, further comprising:
a motor configured to drive the first indicating hand, wherein

the motor includes two coils and is configured to drive the first indicating hand in a forward direction and a reverse direction at the same speed.
The electronic timepiece according to claim 1, further comprising:
a fourth indicating hand configured to display a measurement time of seconds or less and set to have a position indicating 0 seconds as the measurement start position in the chronograph mode; and

a third operation section configured to instruct a measurement start in the chronograph mode, wherein

the display control section is configured to move the fourth indicating hand to the measurement start position by fast forwarding based on the mode switching operation for switching to the chronograph mode, and

the display control section is configured to receive the instruction of the measurement start from the third operation section after the fourth indicating hand moves to the measurement start position and start a time measurement of a chronograph.
The electronic timepiece according to claim 1, wherein
an upper limit time measurable in the chronograph mode is 12 hours.
The electronic timepiece according to claim 1, further comprising:
a storage section configured to store a time in the time display mode, the measurement time in the chronograph mode, and a hand position of the first indicating hand.
The electronic timepiece according to claim 8, wherein
the storage section is configured to store the set measurement start position.