Electronic timepiece

Abstract

To provide an electronic timepiece with a hand position detection mechanism, capable of pivotally supporting a hand spindle with a tenon frame and suppressing an increase in timepiece size.SOLUTION: An electronic timepiece comprises: an optical sensor having first and second elements; a hand spindle; a detection gear arranged between the first and second elements, and provided with detection holes that allow detection light output from the first or second element to pass through; and a ring row receiver in which a metal tenon frame is incorporated, and which pivotally supports the hand spindle via the tenon frame. The ring row receiver comprises a first opening in which the tenon frame is incorporated, and a second opening. The second element is disposed at a position corresponding to the second opening in plan view, a second distance between a center of the second element and an axial center of the hand spindle is larger than a first distance between a center of the first element and the axial center, and either the first element or the second element, which is an element having a light receiving function, can receive detection light passing through the detection holes of the detection gear and the second opening.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electronic timepiece equipped with a hand position detection mechanism. [Background technology]

[0002] Patent Document 1 discloses an electronic timepiece equipped with a hand position detection mechanism that detects the positions of the hour and minute hands. The hand position detection mechanism includes an optical sensor consisting of a light-emitting element and a light-receiving element. The light-emitting element is mounted on a circuit board arranged on the dial side of the main plate, and the light-receiving element is mounted on a circuit board arranged on the back cover side of the train wheel bridge. The center wheel to which the minute hand is attached and the hour wheel to which the hour hand is attached are provided with detection holes that can be detected by an optical sensor when the hour and minute hands are located at their reference positions, and light from the light-emitting element is received by the light-receiving element through an opening formed in the main plate, a detection hole formed in the center wheel and hour wheel, and an opening formed in the train wheel bridge, making it possible to detect that the hour and minute hands have moved to their reference positions.

[0003] In electronic watches, thicker, longer and heavier hands than before are sometimes used due to the increase in dial size and the design of the hands. When attaching such relatively heavy hands to the hand shaft, it is necessary to increase the pressing force when attaching the hands to the hand shaft in order to increase the fixing force of the hand attachment part. In order to increase the pushing force of the hands, as in Patent Document 2, a metal tenon frame is fitted into a bearing hole formed in a train wheel holder made of a resin material, and the shaft portion of the pointer shaft is inserted into a through hole formed in the tenon frame to provide support, thereby adopting a structure that allows the train wheel holder made of resin to withstand the pushing force of the hands. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-217015 A [Patent Document 2] JP 2015-81866 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in an electronic timepiece that uses a tenon frame to support the pointer axle, if a hand position detection mechanism is to be provided as in Patent Document 1, it is necessary to form an opening for hand position detection and an opening for the tenon frame in the train wheel bridge. If these openings are arranged close to each other, the wall thickness between the openings becomes small, which can cause cracks when the tenon frame is hammered into the train wheel bridge, or it can become difficult to ensure impact resistance due to a decrease in the fixing force of the tenon frame. In order to increase the thickness between the openings, it is also possible to place the light-emitting element and light-receiving element of the hand position detection mechanism away from the axis. In this case, the detection holes for the center wheel and hour wheel must also be formed away from the axis, which requires the diameter of each gear to be increased, creating a new problem of the watch becoming larger. For this reason, in an electronic timepiece having a hand position detection mechanism, there is a demand for a structure that allows the pointer shaft to be supported by a tenon frame while preventing the timepiece from becoming larger in size. [Means for solving the problem]

[0006] The electronic timepiece disclosed herein comprises an optical sensor having a first element having either a light emitting function or a light receiving function, and a second element having the other of the light emitting function or the light receiving function, a pointer shaft to which a hand is attached, a detection gear disposed between the first element and the second element, rotating around the pointer shaft, and provided with a detection hole capable of transmitting detection light output from the first element or the second element, and a train wheel bridge having a metal tenon frame incorporated therein and supporting the pointer shaft via the tenon frame, the train wheel bridge having a metal tenon frame incorporated therein. and a second opening disposed between the first opening and a bridge portion, the second element being disposed at a position corresponding to the second opening in a plan view seen from the axial direction of the pointer shaft, a second distance between a center of the second element and an axial center of the pointer shaft in the plan view being greater than a first distance between a center of the first element and the axial center, and an element having the light receiving function, of the first element or the second element, is capable of receiving the detection light that has passed through the detection hole and the second opening of the detection gear. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing an electronic timepiece according to an embodiment. [Diagram 2] 3 is a cross-sectional view showing a main part of a hand position detection mechanism of the electronic timepiece. FIG. [Diagram 3] FIG. 2 is an exploded perspective view showing a main part of a hand position detection mechanism of the electronic timepiece. [Figure 4] FIG. 2 is a plan view showing the minute hand drive mechanism of the electronic timepiece. [Diagram 5] FIG. 4 is an exploded perspective view showing the fixing structure of the tenon frame of the electronic timepiece. [Figure 6] FIG. 2 is a perspective view showing a tenon frame and a jig of the electronic timepiece. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An electronic timepiece 1 according to an embodiment of the present disclosure will now be described with reference to the drawings. As shown in FIG. 1, the electronic watch 1 is a wristwatch worn on the user's wrist and includes an outer case 2, a circular dial 3, hour hand 4, minute hand 5, and second hand 6 as hands, a date wheel 7, a crown 8, and buttons 9A and 9B.

[0009] 2, a movement 10 is housed inside the exterior case 2 of the electronic timepiece 1. The movement 10 includes a solar panel 11, an antenna 12, a circuit board 13, a main plate 14, a train wheel bridge 15, a circuit block 16, and a magnetic shield 17. Furthermore, at the planar center position of the movement 10, there are coaxially arranged an hour wheel 21, a center wheel 22, and a seconds wheel 23, which are journalled on a synthetic resin main plate 14 and a train wheel bridge 15 and are arranged to pass through openings formed in the solar panel 11, the antenna 12, and the circuit board 13.

[0010] As shown in Figures 2 and 3, the hour wheel 21 is composed of a hour gear 211 and a cylindrical hour wheel body 212 fixed to the hour gear 211, and the hour hand 4 is attached to the tip of the hour wheel body 212 on the dial 3 side. The center wheel & pinion 22 is configured with a center gear 221 and a cylindrical center arbor 222 fixed to the center gear 221, and the minute hand 5 is attached to the tip of the center arbor 222 on the dial 3 side. The second wheel 23 is configured to include a second gear 231 and a second hand shaft 232 fixed to the second gear 231, and the second hand 6 is attached to the tip of the second hand shaft 232 on the dial 3 side.

[0011] A guide pipe 25 fixed to the main plate 14 is inserted into the cylindrical wheel body 212 of the cylindrical wheel 21 , and the cylindrical wheel 21 is supported by the main plate 14 and the guide pipe 25 so as to be freely rotatable. The center arbour 222 of the center wheel & pinion 22 is inserted into the guide pipe 25, and a second hand shaft 232 of the second wheel 23 is inserted into the center arbour 222. Therefore, the hour wheel 21 is supported rotatably by the second wheel 23 and the guide pipe 25. A tenon 233 is provided at the tip of the second hand shaft 232 of the second wheel 23 on the back cover side, and this tenon 233 is journalled on a metal tenon frame 40 attached to a synthetic resin train wheel bridge 15. In addition, the second pinion spring 50 abuts against the tip of the tenon 233. The second pinion spring 50 urges the second hand shaft 232 toward the dial 3 by abutting against the tip of the tenon 233. As a result, the second wheel 23 abuts against the center wheel 22 via the center retainer 225, and the center wheel 22 abuts against the guide pipe 25, so that they rotate stably and the hands such as the second hand 6 and minute hand 5 attached to the second wheel 23 and the center wheel 22 can be prevented from wobbling.

[0012] The movement 10 is equipped with a motor and a wheel train capable of independently driving the hour hand 4, minute hand 5, second hand 6, and date wheel 7. That is, although not shown, the hour hand 4 is driven by rotating the hour wheel 21 with the hour motor and hour wheel train. Similarly, the second hand 6 is driven by rotating the second wheel 23 with the second motor and second wheel train, and the date wheel 7 is driven by rotating the date driving wheel with the calendar motor and calendar wheel train. 4, the minute hand 5 is driven by rotating the center wheel 22 via a minute motor 30 and a minute wheel train. The minute motor 30 includes a rotor 31, and the rotor 31 is provided with a pinion (not shown). The minute wheel train includes a fifth wheel 32 that meshes with the pinion of the rotor 31 of the minute motor 30, and a third wheel 33 that meshes with the pinion 321 of the fifth wheel 32. The pinion 331 of the third wheel 33 meshes with the center gear 221 of the center wheel 22, thereby driving the center wheel 22 and the minute hand 5.

[0013] 2 and 5, the gear train bridge 15 is formed with a first opening 151 into which the metal tenon frame 40 is press-fitted, and a second opening 152 in which the light receiving element 75, which is the second element provided in the circuit block 16, is disposed. The first opening 151 and the second opening 152 are disposed with a bridge portion 155 in between. A step 153 is formed around the first opening 151 on the surface of the gear train bridge 15 facing the main plate 14. The tenon frame 40 has a flange 41 that protrudes from the outer circumferential surface, and is positioned in the axial direction of the second hand shaft 232, i.e., in the thickness direction of the electronic timepiece 1, by abutting this flange 41 against the step 153.

[0014] When attaching the hands (hour hand 4, minute hand 5, second hand 6) to the hour wheel 21, center wheel 22, and second wheel 23, as shown in Figure 6, a jig 60 called an exterior pallet is abutted against the tenon frame 40 from the back cover side of the train wheel bridge 15, and holds the force applied to the tenon frame 40 and the train wheel bridge 15 when the hands are pressed in. Since the pointer is pushed in with the second pinion spring 50 assembled, the jig 60 is formed with a groove 61 so as not to interfere with the second pinion spring 50. This groove 61 opens into a contact surface 62 that contacts the train wheel bridge 15 of the jig 60, and the contact surface 62 is formed in a substantially U-shape. Also, a notched surface 63 is formed on the side surface of the jig 60 so as not to interfere with the light receiving element 75, the circuit block 16, etc. The diameter of the tenon frame 40 must be such that the jig 60 can abut against the outside of the assembled second pinion spring 50, and making the diameter too large will result in the diameter of the watch becoming larger. Therefore, the diameter of the tenon frame 40 is preferably 0.90 mm or more and 1.20 mm or less, and more preferably 1.00 mm or more and 1.1 mm or less.

[0015] [Hand position detection mechanism] Next, the optical sensor of the hand position detection mechanism of this embodiment will be described. In this embodiment, an hour hand optical sensor, a minute hand optical sensor, and a second hand optical sensor that detect the hand positions of the hour hand 4, minute hand 5, and second hand 6 are provided. Although not shown, the hour hand optical sensor is composed of a light emitting element provided on the circuit board 13 and a light receiving element provided on the circuit block 16. The light emitting element and light receiving element of the hour hand optical sensor are arranged across the gear of the hour train wheel that drives the hour wheel 21, thereby detecting that the hour hand 4 is at the reference position, specifically the 12 o'clock position. Although not shown, the second hand optical sensor, like the hour hand optical sensor, is configured with a light emitting element provided on the circuit board 13 and a light receiving element provided on the circuit block 16. The light emitting element and light receiving element of the second hand optical sensor are arranged across the gear of the second wheel train that drives the second wheel 23, thereby detecting that the second hand 6 is at the reference position, specifically the 12 o'clock position. The hour hand optical sensor and the second hand optical sensor are disposed outside the hour wheel 21 and the second wheel 23, and therefore are not provided in a position close to the tenon frame 40.

[0016] 2 to 5, the minute hand optical sensor includes a light-emitting element 71, which is a first element provided on the circuit board 13, and a light-receiving element 75, which is a second element provided on the circuit block 16. The light-emitting element 71 is composed of a rectangular plate-shaped LED chip or the like, and is covered with a light-transmitting sealing resin 72. The light receiving element 75 is composed of a light receiving transistor or the like, and has a light receiving area larger in planar size than the light emitting element 71. The light receiving area is also called an active area, and means an area in the light receiving element 75 where light can be detected. The light receiving area is provided on the surface of the light receiving element 75 facing the light emitting element 71, and is provided over almost the entire surface of the light receiving element 75 excluding the electrodes and the like. The light receiving element 75 is also covered with a translucent sealing resin 76. In addition, an opening 141 that can transmit the detection light output from the light-emitting element 71 is formed in the base plate 14 at a position overlapping with the light-emitting element 71 and the light-receiving element 75 in a plan view. In addition, although not shown, the base plate 14 has openings similar to the opening 141 formed in positions overlapping with the hour hand optical sensor and the second hand optical sensor in a plan view.

[0017] As shown in Figures 2 and 3, the barrel gear 211 of the hour wheel 21, the center gear 221 of the center wheel 22, the third wheel 33, and the fifth wheel 32 are formed with detection holes 213, 223, 333, and 323 which are capable of overlapping with each other in a planar view seen from the axial direction of the second hand axis 232, which is the pointer axis, the second arbor 222, and the barrel wheel body 212, and which are used for detection by the minute hand optical sensor. There are 12 detection holes 213 formed in the hour gear 211 at intervals of 30 degrees in the rotational direction. As a result, one of the detection holes 213 is positioned between the light emitting element 71 and the light receiving element 75 at every hour on the hour when the minute hand 5 indicates the 12 o'clock position. The detection hole 223 formed in the center wheel 221 is formed at a position where it is located between the light emitting element 71 and the light receiving element 75 when the minute hand 5 indicates the 12 o'clock position. The third wheel 33 has two detection holes 333 formed at 180 degree intervals in the rotational direction, and one of the detection holes 333 is positioned between the light-emitting element 71 and the light-receiving element 75 when the minute hand 5 indicates the 12 o'clock position. The detection hole 323 formed in the fifth wheel 32 is formed at a position where it is located between the light emitting element 71 and the light receiving element 75 when the minute hand 5 indicates the 12 o'clock position. Four light transmitting elongated holes 234 are formed at 90 degree intervals in the rotational direction in the second wheel 231 of the second wheel 23. Therefore, when the position detection process for the minute hand 5 is executed while the hands are moving, the position detection process for the minute hand 5 can be executed as long as the elongated holes 234 are positioned between the light emitting element 71 and the light receiving element 75 even if the second wheel 23 moves.

[0018] As described above, when the minute hand 5 indicates the 12 o'clock position, the detection holes 213, 223, 333, 323 and the long hole 234 overlap the light emitting element 71 and the light receiving element 75 in a plan view. Specifically, the planar center C1 of the light emitting element 71 coincides with the planar centers of the detection holes 213, 223, 333, 323 in a plan view. In addition, the areas of the detection holes 213, 223, 333, 323 are made larger than the irradiation area of ​​the detection light output from the light emitting element 71, and are made to have a size that allows the detection light output from the light emitting element 71 to pass through. Therefore, the detection light output from the light emitting element 71 is configured to pass through each of the detection holes 213, 223, 333, 323 and further pass through one of the long holes 234 and be received by the light receiving element 75, thereby making it possible to detect that the minute hand 5 is located at a position indicating the 12 o'clock position, which is the reference position. As shown in Figures 2 and 4, the barrel gear 211 and the second gear 221 rotate around the second hand axis 232, which is the pointer axis, and are detection gears that are arranged in the axial direction of the pointer axis between the light-emitting element 71, which is the first element, and the light-receiving element 75, which is the second element, and are provided with detection holes 213, 223 that can transmit the detection light output from the light-emitting element 71.

[0019] As shown in Figures 2 and 4, if a first distance between a planar center C1 of the light-emitting element 71, which is the first element, and an axial center A of the second wheel 23, which is the pointer axis, is L1, and a second distance between a planar center C2 of the light-receiving element 75, which is the second element, and an axial center A of the second wheel 23, which is the pointer axis, is L2, then L2>L1. 4, the light receiving element 75 has a larger planar size than the light emitting element 71, and the overlapping positions of the light emitting element 71 and the detection holes 213, 223, 333, and 323 in a plan view are set to be within the light receiving area of ​​the light receiving element 75. Therefore, even if the planar center C1 of the light emitting element 71 and the planar center C2 of the light receiving element 75 do not coincide with each other, the detection light output from the light emitting element 71 passes through the detection holes 213, 223, 333, and 323 and further passes through any of the long holes 234 to be received by the light receiving element 75. For this reason, the amount of detection light output from the light-emitting element 71 and the detection sensitivity at the light-receiving element 75 can be made the same as when the planar center C1 of the light-emitting element 71 coincides with the planar center C2 of the light-receiving element 75. In other words, if the light-emitting element 71 and the detection holes 213, 223, 333, 323 are disposed within the light-receiving area of ​​the light-receiving element 75 in a plan view, the planar positions of the light-emitting element 71 and the light-receiving element 75 can be shifted relatively without affecting the detection of the hand position.

[0020] In this embodiment, L2-L1 is set to be 0.10 mm or more and 0.20 mm or less. For example, L1 is 1.6 mm, L2 is 1.75 mm, and L2-L1 is 0.15 mm. The minimum width dimension W of the bridge portion 155 is set to be 0.25 mm or more. Here, if L2-L1 is made larger than 0.20 mm, the overlapping area between the light emitting element 71 and the light receiving area of ​​the light receiving element 75 becomes smaller, and the detection sensitivity of the light receiving element 75 decreases. Furthermore, if L2-L1 is made smaller than 0.10 mm, the planar center C1 of the light-emitting element 71 and the planar center C2 of the light-receiving element 75 must be brought closer together, which would result in a thinner bridge portion 155 and larger barrel gears 211 and other components, resulting in a larger electronic watch 1. For example, if the planar center C2 of the light receiving element 75 is moved closer to the planar center C1 without changing the position of the light emitting element 71, the sealing resin 76 and circuit block 16 will move closer to the axial center A, and it will be necessary to reduce the width dimension W of the bridge portion 155. In this case, the width dimension W of the bridge portion 155 will be smaller, which may cause the bridge portion 155 to crack when the tenon setting 40 is hammered into the first opening 151, or the fixing force of the tenon setting 40 will decrease, making it difficult to ensure shock resistance in the event that the electronic timepiece 1 is dropped. Furthermore, if the planar center C1 of the light-emitting element 71 is moved closer to the planar center C2 without changing the position of the light-receiving element 75, the hole positions of each detection hole 213, 223 and the long hole 234 formed at a position overlapping with the light-emitting element 71 in a planar view will also be positioned away from the axial center A, so that the diameters of gears such as the barrel gear 211, second gear 221, and second gear 231 will also need to be increased, resulting in an increase in the size of the electronic watch 1. In contrast, by setting L2-L1 to 0.10 mm or more and 0.20 mm or less, a decrease in the detection sensitivity of the light receiving element 75 can be prevented, the width dimension W of the bridge portion 155 can be ensured to be 0.25 mm or more, preventing the occurrence of cracks, ensuring impact resistance, and preventing the electronic watch 1 from becoming larger.

[0021] [Effects of the embodiment] In the electronic timepiece 1, a metal tenon frame 40 is provided on the train wheel bridge 15, and the tenon 233 of the second wheel 23 is journaled by the tenon frame 40, so that when the minute hand 5 and second hand 6 are pressed into the pointer shaft such as the center arbor 222 of the center wheel & pinion 222 or the second hand shaft 232 of the second wheel 23, the force applied to the pointer shaft can be received by the tenon frame 40. For this reason, a pointer with a large size, such as a large length or width, or a large weight can be attached to the pointer shaft. Since the second distance L2 between the planar center C2 of the light receiving element 75, which is the second element, in a plan view and the axial center A of the seconds wheel 23, which is the hand axis, is greater than the first distance L1 between the planar center C1 of the light emitting element 71, which is the first element, and the axial center A of the hand axis, the first opening 151 into which the tenon frame 40 is incorporated and the second opening 152 in which the light receiving element 75 is disposed can be disposed apart, and the width dimension W of the bridge portion 155 can also be increased. This makes it possible to prevent cracks from occurring in the train wheel bridge 15 when the tenon frame 40 is hammered into it, ensures the fixing force of the tenon frame 40, and allows it to withstand the pushing force of the hands and improves impact resistance.

[0022] The light receiving element 75 can receive the detection light output from the light emitting element 71 and transmitted through the detection holes 213, 223, 333, 323 of the barrel gear 211, the center gear 221, the third wheel 33, the fifth wheel 32, the long hole 234 of the second gear 231, the opening 141, and the second opening 152, so that the hand position can be detected reliably. Furthermore, since the planar center C2 of the large-sized light receiving element 75 is located farther from the axial center A than the planar center C1 of the light emitting element 71, there is no need to increase the size of the barrel gear 211 and the center gear 221 having the detection holes 213 and 223, or the second gear 231 having the long hole 234, and the planar size of the electronic timepiece 1 can also be prevented from becoming large. Since the light emitting element 71 is provided so as to be able to be placed in the detection holes 213, 223, 333, 323 and the long hole 234 in a plan view, all the detection light output from the light emitting element 71 can be transmitted through the detection holes 213, 223, 333, 323 and the long hole 234. Also, since the light emitting element 71 is arranged in the light receiving area of ​​the light receiving element 75 in a plan view, all the detection light can be irradiated onto the light receiving area. Therefore, compared to a conventional optical sensor in which the planar center C1 of the light emitting element 71 and the planar center C2 of the light receiving element 75 are aligned, there is no need to increase the amount of detection light output from the light emitting element 71 or increase the detection sensitivity of the light receiving element 75. Therefore, the planar position of the light receiving element 75 can be shifted with respect to the light emitting element 71 without affecting the setting of the hand position detection.

[0023] Because the tenon 233 of the seconds wheel 23 has a small radial dimension, the light receiving element 75, which has a large planar size, can be arranged around the tenon frame 40 that supports the tenon 233. Also, because the light emitting element 71, which has a smaller planar size than the light receiving element 75, is arranged around the barrel wheel body 212, which has a larger radial dimension than the tenon 233, it is possible to suppress an increase in the planar size and thickness of the electronic timepiece 1. Furthermore, since a clock IC and the like are also mounted on the circuit block 16, the IC and the light receiving element 75 can be mounted on the same board, facilitating testing of the electrical characteristics of the circuit.

[0024] Since the tenon frame 40 is provided with the flange 41, it can easily receive the force applied to the tenon frame 40, and can support a larger pushing force than a tenon frame without the flange 41.

[0025] [Other embodiments] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention. In the above embodiment, the light emitting element 71 is arranged in the detection holes 213, 223 of the barrel gear 211 and the second gear 221, which are detection gears, in a plan view, and is arranged in the light receiving area of ​​the light receiving element 75, but the light emitting element 71 may be arranged so that a part of the light emitting element 71 is located outside the detection holes 213, 223 and the light receiving area of ​​the light receiving element 75 in a plan view. That is, it is sufficient that at least a part of the detection light output from the light emitting element 71 is transmitted through the detection holes 213, 223 and received in the light receiving area of ​​the light receiving element 75 to perform hand position detection. In this case, the amount of detection light may be increased by changing the type of the light emitting element 71 or increasing the drive current of the light emitting element 71, or the detection sensitivity may be increased by increasing the detection resistance value of the light receiving element 75.

[0026] In the above embodiment, a light-emitting element 71 was used as the first element provided on the circuit board 13 arranged on the dial 3 side of the main plate 14, and a light-receiving element 75 was used as the second element provided on the circuit block 16 arranged on the back cover side of the gear train bridge 15. However, conversely, a light-receiving element may be used as the first element provided on the circuit board 13, and a light-emitting element may be used as the second element provided on the circuit block 16. In the above embodiment, in addition to the detection holes 213, 223 of the barrel gear 211 and the second gear 221, detection holes 333, 323 are also formed in the third wheel 33 and the fifth wheel 32. However, the light-emitting element 71 and the light-receiving element 75 may be arranged in a position that does not overlap with the third wheel 33 and the fifth wheel 32 in a planar view, and the detection light output from the light-emitting element 71 may be transmitted through the detection holes 213, 223 of the barrel gear 211 and the second gear 221 and the long hole 234 of the seconds gear 231 and received by the light-receiving element 75.

[0027] In the above embodiment, the hour hand 4, minute hand 5, and second hand 6 are driven by independent motors and wheel trains, but multiple hands may be driven by a single motor. For example, the hour hand 4 and minute hand 5 may be driven by a single hour / minute hand motor and wheel train, or the hour hand 4, minute hand 5, and second hand 6 may be driven by a single hour / minute / second hand motor and wheel train. The tenon frame 40 is not limited to one having a flange 41, and may be one not having a flange 41.

[0028] [Summary of this disclosure] The electronic timepiece disclosed herein comprises an optical sensor having a first element having either a light emitting function or a light receiving function, and a second element having the other of the light emitting function or the light receiving function, a pointer shaft to which a hand is attached, a detection gear disposed between the first element and the second element, rotating around the pointer shaft, and provided with a detection hole capable of transmitting detection light output from the first element or the second element, and a train wheel bridge having a metal tenon frame incorporated therein and supporting the pointer shaft via the tenon frame, the train wheel bridge having a metal tenon frame incorporated therein. and a second opening disposed between the first opening and a bridge portion, the second element being disposed at a position corresponding to the second opening in a plan view seen from the axial direction of the pointer shaft, a second distance between a center of the second element and an axial center of the pointer shaft in the plan view being greater than a first distance between a center of the first element and the axial center, and an element having the light receiving function, of the first element or the second element, is capable of receiving the detection light that has passed through the detection hole and the second opening of the detection gear. According to the electronic timepiece of the present invention, the train wheel bridge is provided with a metal tenon frame, and the pointer shaft is supported by the tenon frame, so that the force applied to the pointer shaft when the pointer is pushed into the pointer shaft can be received by the tenon frame, and a pointer with a large size and weight can be attached. In addition, the second distance between the center of the second element and the axis center of the pointer shaft in a plan view is larger than the first distance between the center of the first element and the axis center of the pointer shaft, so that the first opening in which the tenon frame is incorporated and the second opening in which the second element of the optical sensor is disposed can be disposed apart, and the width dimension of the bridge portion provided between these openings can also be increased. This makes it possible to prevent the train wheel bridge from cracking when the tenon frame is hammered into the train wheel bridge, ensure the fixing force of the tenon frame, and endure the pushing force of the pointer, and improve impact resistance. In addition, the element with a light receiving function can receive detection light transmitted through the detection hole and the second opening of the detection gear, so that the hand position can be detected reliably. Furthermore, since the second element can be positioned away from the pointer axis relative to the first element as long as it does not affect hand position detection, there is no need to increase the size of the detection gear having the detection hole, and the size of the watch can be prevented from increasing.

[0029] In the electronic watch disclosed herein, it is preferable that the first element is a light-emitting element having the light-emitting function, the second element is a light-receiving element having the light-receiving function, and the light-emitting element is, when viewed in the plane, arranged within the detection hole of the detection gear and within the light-receiving area of ​​the light-receiving element. According to the electronic timepiece of the present disclosure, the light-emitting element is arranged so as to be able to be placed in the detection hole of the detection wheel in a plan view, so that all the detection light output from the light-emitting element can pass through the detection hole. Also, since the light-emitting element is arranged in the light-receiving area of ​​the light-receiving element in a plan view, all the detection light that passes through the detection hole of the detection wheel can be irradiated onto the light-receiving area. Therefore, compared to conventional optical sensors in which the center of the light-emitting element and the center of the light-receiving element are aligned, there is no need to increase the amount of detection light output from the light-emitting element or to increase the detection sensitivity of the light-receiving element. Therefore, the planar position of the light-receiving element, which is the second element, can be shifted relative to the light-emitting element, which is the first element, without affecting the setting of the hand position detection.

[0030] In the electronic timepiece of the present disclosure, if the second distance is L2 and the first distance is L1, it is preferable that L2-L1 be 0.10 mm or more and 0.20 mm or less. According to the electronic watch disclosed herein, it is possible to prevent a decrease in the detection sensitivity of the light receiving element, ensure the width dimension of the bridge portion to prevent cracks, ensure impact resistance, and prevent the electronic watch from becoming larger.

[0031] In the electronic timepiece of the present disclosure, it is preferable that the width dimension of the bridge portion is 0.25 mm or greater. According to the electronic watch disclosed herein, by making the width dimension W of the bridge portion 0.25 mm or more, it is possible to reliably prevent cracks from occurring in the bridge portion when the mortise and tenon setting is hammered into the first opening, and the fixing force of the mortise and tenon setting is also improved, thereby improving the impact resistance if the electronic watch is dropped, for example.

[0032] In the electronic timepiece disclosed herein, it is preferable that the pointer is a minute hand, and the detection gear is a gear that drives the minute hand. According to the electronic timepiece disclosed herein, the metal tenon frame can withstand the force of pushing the minute hand when attaching it to the pointer shaft, as well as the impact force when the watch is dropped, making it possible to use a large minute hand. This allows for greater freedom in the size and weight of the minute hand available while maintaining the size of the electronic timepiece, and also increases the freedom in the design of the electronic timepiece. [Explanation of symbols]

[0033] 1...electronic clock, 4...hour hand, 5...minute hand, 6...second hand, 10...movement, 13...circuit board, 14...main plate, 15...wheel train bridge, 16...circuit block, 21...hour wheel, 22...second wheel, 23...second wheel, 30...minute motor, 32...fifth wheel, 33...third wheel, 40...mortise frame, 41...guard, 50...second pinion spring, 60...jig, 71...light-emitting element, 75...light-receiving element, 151...first opening, 152...second opening, 155...bridge portion, 211...hour gear, 213...detection hole, 221...second gear, 223...detection hole, 231...second gear, 233...mortise, 234...long hole, 323...detection hole, 333...detection hole.

Claims

1. an optical sensor including a first element having one of a light emitting function and a light receiving function, and a second element having the other of the light emitting function and the light receiving function; a pointer shaft on which the pointer is attached; a detection gear disposed between the first element and the second element, rotating around the axis of the pointer, and having a detection hole through which detection light output from the first element or the second element can pass; a train wheel bridge having a metal tenon frame incorporated therein and supporting the pointer shaft via the tenon frame; Equipped with The gear train bridge is a first opening into which the tenon frame is fitted; a second opening disposed across the first opening and a bridge portion; the second element is disposed at a position corresponding to the second opening in a plan view seen from an axial direction of the stick, In the plan view, a second distance between a center of the second element and an axis center of the pointer shaft is greater than a first distance between a center of the first element and the axis center; Of the first element and the second element, the element having the light receiving function is capable of receiving the detection light transmitted through the detection hole and the second opening of the detection gear. An electronic watch characterized by:

2. 2. The electronic timepiece according to claim 1, the first element is a light-emitting element having the light-emitting function, the second element is a light receiving element having the light receiving function, The light emitting element is disposed in a detection hole of the detection gear and in a light receiving area of ​​the light receiving element in the plan view. An electronic watch characterized by:

3. 2. The electronic timepiece according to claim 1, When the second distance is L2 and the first distance is L1, L2-L1 is equal to or greater than 0.10 mm and equal to or less than 0.20 mm. An electronic watch characterized by:

4. 2. The electronic timepiece according to claim 1, The width of the bridge portion is 0.25 mm or more. An electronic watch characterized by:

5. 2. The electronic timepiece according to claim 1, The pointer is a minute hand, The detection gear is the gear that drives the minute hand. An electronic watch characterized by:

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