JPH02284092A - Analog electronic watch - Google Patents

Abstract

PURPOSE:To expand the degree of freedom in the disposition of mechanical parts by disposing a disk-shaped oscillator in such a manner that the central axis thereof is in parallel with the central axis of rotation of the hand and rotating a wheel train by the friction torque received by a rotor brought into pressurized contact with the outer periphery of the oscillator. CONSTITUTION:An Al ring 7 is integrally fitted to the outer periphery of the ceramics oscillator 6. Since a friction spring 10 presses an upper tenon 12 of the rotor, the tapered part on the outer periphery of the ring 7 is surely brought into pressurized contact with the tapered part of a lower tenon 9 of the rotor 8. the rotor 8 brought into pressurized contact with the lower tenon 9 receives the friction torque generated by the centroid rotation and is thereby rotated when the oscillator 6 acts as an ultrasonic rotating oscillator. The rotation of the rotor 8 is transmitted in the route of a fifth wheel 13a, a fifth pinion 13b and a fourth wheel 14a and the second hand 4 mounted to the front end of the fourth wheel and pinion 14 is driven (rotated). The excitation period of the oscillator 6, i.e. the time when a sinusoidal wave is impressed to an electrode, is set (on/off) in such a manner that the second hand 3 rotates at the prescribed angle of a mechanical angle on a dial 2 at every second.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for driving hands for time display of an analog electronic watch.

[Conventional technology]

Conventional analog electronic watches transmit the rotation of the rotor of an electromagnetic step motor placed on the main plate through a fifth wheel and a fourth wheel to drive the second hand, and a fifth wheel that engages with the fourth wheel. It is well known that the minute hand is driven through the fifth wheel, and the hour hand is driven through the opening wheel and hour wheel that mesh with the fifth wheel, and is currently widely used in practice. In this conventional method, the front wheel train and step motor other than the hour wheel are placed on the front side of the main plate, and the dial and hands are placed on the main plate, taking into consideration the thinness of analog electronic watches and the space efficiency of component placement. It is placed on the back side.

[Problem to be solved by the invention]

However, conventional analog electronic watches have the following problems.

In other words, because the step motor is located on the same side of the main plate as the so-called front gear train, such as the fourth wheel and fifth wheel, the step motor occupies a relatively large space in the layout, and The degree of freedom in arranging parts (for example, switching mechanisms, batteries, etc.) is reduced. This is particularly noticeable in women's analog Miko watches, which have a small main plate. Furthermore, it is difficult to significantly reduce the size of the current level in order to ensure enough torque to withstand load fluctuations in the wheel train and to keep current consumption low. However, placing the step motor on the same side of the main plate as the dial (opposite the front wheel train) hinders the ability to make analog electronic watches thinner.
Not practical.

Furthermore, step motors have many components such as magnets, stators, and coil blocks, and are expensive.

In addition to these problems, since conventional analog electronic watches use electromagnetic step motors, they also have the problem of being affected by external magnetic fields, such as making mistakes and stopping. For this reason, parts such as a magnetic shield plate and a magnetic shield frame are required, which is an obstacle to making analog electronic watches thinner and lower in cost.

The present invention is intended to solve the above-mentioned problems.The purpose of the present invention is to eliminate the conventional electromagnetic step motor, increase the degree of freedom in the arrangement of wheel trains and other mechanical parts, and provide an analog electronic clock. The goal is to achieve thinner, lower cost, and higher magnetic resistance.

[Means to solve the problem]

The analog electronic timepiece of the present invention has at least a main plate, a dial, a pointer, and a wheel train for driving the pointer. The wheel train is arranged so that its center axis is substantially parallel to the rotation center axis of the pointer, and the wheel train is rotated by the friction torque received by a rotor that is crimped to the outer periphery of the disc-shaped ceramic vibrator.

[Embodiment] FIG. 1 is a sectional view of the main parts of an analog electronic timepiece showing an embodiment of the present invention. 1 is a base plate made of a resin molding material such as polycarbonate, 2 is a dial plate, and 3, 4, and 5 are a second hand, a minute hand, and an hour hand, respectively.

Reference numeral 6 denotes a disc-shaped ceramic vibrator made of a piezoelectric material such as lead zirconate titanate, which is placed between the dial plate 2 and the main plate 1, and is fixed by press-fitting its inner periphery into the main plate 1. . Also, 7 is an aluminum ring,
It is fitted and integrated with the outer periphery of the ceramic vibrator 6. Further, the outer periphery of the ring 7 is tapered. 8 is a rotor, and the groove 9 below the rotor has the same taper processing as the ring 7. Reference numeral 10 denotes a presser spring, one end of which is fixed on the train wheel bridge [1], and one end of which presses down the upper slot 12 of the rotor 8. As a result, the outer circumferential tapered portion of the ring and the tapered portion of the lower groove 9 of the rotor 8 are securely pressed against each other. 13 is the fifth wheel, 14 is the fourth wheel, 15 is the second wheel, and 16 is the hour wheel.

FIG. 2 is a plan view showing details of the disc-shaped ceramic vibrator 6. As shown in FIG. The vibrator is a radial vibrator polarized in the thickness direction, and the disk is polarized so that each semicircle has opposite polarity (positive/negative). An electrode 18 (referred to as a ground electrode) is formed on almost the entire surface on one side, and fan-shaped electrodes 19, 20, 21, 2 are formed on the positive and negative domains of the other side, each opening at a right angle to a quarter circle.
2, the positive electrodes 19.20 are shown with a (+) sign, and the negative electrodes 21.22 are shown with a (-) sign in the figure. A method such as screen stamping is used to form such electrodes.

As shown in FIG. 2, electrode 20.22 and electrode 19.2
1, respectively, and connect the lead wires 23 and 24 to the ground electrode 1.
Two-phase sinusoidal voltage v with a phase difference of 90″ each between 8
1, when v2 is applied, the disc-shaped ceramic resonator 6 becomes
It is known that near the resonance frequency, the movement of the center of gravity due to vibration causes the ultrasonic rotating transducer to rotate eccentrically with respect to the center of the original circle. (Unexamined Japanese Patent Publication No. 63-18
1676.181677) When the ceramic vibrator 6 operates as an ultrasonic rotary vibrator in this way, the rotor 8 whose lower groove 9 is pressed against the ring 7 integrated with the ceramic vibrator 6 in FIG.
The uke rotates due to the massat torque caused by the rotation of the center of gravity. Rotor 8
The rotation of 5th gear 13a, 5th pinion 13b1, 4th gear 1
The second hand 3 attached to the tip of the fourth wheel & pinion 14 is driven.

The excitation period of the ceramic oscillator 6, that is, the time during which a sinusoidal voltage is applied to the electrodes, is such that the second hand 3 moves on the dial by 6 mechanical angles every second.
Supplementary setting (ONloFF) for rotation is made. Further, instead of moving the second hand 3 in steps as described above, the ceramic vibrator 6 may be continuously excited to move the second hand 3 in a smooth sweeping motion.

The rotation of the fourth die 14 is transmitted to the second gear 15a via a fifth wheel (not shown) at a reduction ratio of 1/60, thereby driving the minute hand 4. The rotation of the fifth wheel & pinion 15 is transmitted to the hour wheel 16 at a reduction ratio of 1/12 via a head wheel (not shown), thereby driving the hour hand 5. Since this minute hand and hour hand drive structure is well known in general analog electronic watches, detailed explanation will be omitted.

In this embodiment, the inner periphery of the ceramic vibrator 6 is fixed to the base plate 1 in a positive manner, but the inner periphery may be fixed by adhesive with a clearance fit. Further, although this embodiment uses a three-hand analog electronic watch as an example, the present invention does not go beyond the scope of the present invention if it is applied to a two-hand analog electronic watch without a second hand.

Further, in this embodiment, the central axis of the ceramic vibrator 6 is configured to coincide with the rotation center of the pointer, that is, the axis of the No. 4 die 14. It is sufficient if it is approximately parallel to the rotation center axis.

〔Effect of the invention〕

As described above, according to the present invention, in an analog electronic watch having at least a main plate, a dial, hands, and a wheel train for driving the hands, a disc-shaped ceramic whose center of gravity rotates in accordance with a rotating electric field is used. By arranging the vibrator so that its central axis is approximately parallel to the rotation center axis of the pointer, and rotating the wheel train by the friction torque received by the rotor crimped to the outer periphery of the disc-shaped ceramic vibrator, This eliminates the need for a conventional electromagnetic step motor, increases the degree of freedom in arranging the wheel train and other mechanical parts, and has the advantage of making analog electronic watches smaller and thinner.

Furthermore, since a ceramic vibrator is used, the movement of the hands is not affected by external magnetic fields, and a magnetically resistant watch can be realized without using separate parts such as a magnetically resistant plate.

As described above, the practical effects of the present invention are great.

[Brief explanation of drawings]

FIG. 1 shows an analog electronic 17 illustrating an embodiment of the present invention.
・If you press the second, more than 1...Main plate 2...Dial 3...Second hand 4...Minute hand 5...Hour hand 6...Ceramic vibrator 7...Ring 8・φ・Rotor 10・... Pusher spring 11 ... Gear train bridge 13 ... Fifth wheel & pinion 14 ... Fourth type 15 ... Fifth wheel & pinion 16 ... Hour wheel applicant Seiko Epson Co., Ltd. agent Patent attorney Suzuki Kisanbe (1 other person) 2nd alt
to) Figure 2G)

Claims (1)

[Claims] In an analog electronic watch that has at least a main plate, a dial, a pointer, and a wheel train that drives the pointers, a disc-shaped ceramic vibrator whose center of gravity rotates in response to a rotating electric field is used, and its center axis is the pointer. Arranged so that it is approximately parallel to the rotation center axis,
An analog electronic timepiece characterized in that the wheel train is rotated by frictional torque received by a rotor that is crimped onto the outer periphery of the disc-shaped ceramic vibrator.