JPS6379091A - Switch apparatus of electronic time-piece - Google Patents

Abstract

PURPOSE:To simplify the title apparatus, by a method wherein the signal of the second piezoelectric element generated by the impact force applied to a clock case is detected through a detection circuit and a level discrimination circuit even when an alarm signal is applied to the first piezoelectric element. CONSTITUTION:The alarm signal outputted from the electronic circuit mounted on an electronic circuit board 6 is applied to the electrode 3c of a piezoelectric element 3 through an alarm electrode 6a and an alarm connection spring 4. The electrode 3b of the element 3 is short-circuited to the + electrode of a battery 7 through a back plate 2 and a battery press plate 9. The piezoelectric material 3a of the element 3 receives the application of an alarm signal by electrodes 3b, 3c to generate strain and the back plate 2 vibrates to generate alarm sound. By the strain generated material 3a, voltage is generated in the part where electrodes 3b, 3d are formed in opposed relation to each other. When external impact force is applied to the back plate 2 in this state, a piezoelectric signal is generated between the electrodes 3b, 3d by the vibration due to said impact force and transmitted to the electrode 6b of the board 6 through a detection connection spring 5 to be inputted to the detection circuit of an electronic circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switch device in an electronic timepiece.

[Conventional technology]

The switch structure used in conventional electronic watches uses a mechanical contact system operated by a Bushet button or crown.

However, in recent years, the idea of using a piezoelectric element to use the signal generated when an impact is applied as an input signal for a switch has been considered, and improvements in technology have made it possible to put it into practical use.

The technical idea regarding the piezoelectric element switch as described above is disclosed, for example, in Japanese Patent Application Laid-Open No. 53-80263 (Japanese Patent Application No. 51-155).
As disclosed in No. 749), a piezoelectric element fixed to a part of a watch case is used to operate the watch electronic circuit by striking the watch (and thereby generating an impact signal).

JP-A-53-80263 further applies the above-mentioned technical concept to a device that uses not only the switch function (by switching the switch to connect the electrode to the alarm circuit, it can be operated in conjunction with an alarm sound generator). There is also a description that it can be done.

[Problem that the invention seeks to solve]

However, for example, when trying to use both the functions of an alarm generator and a switch in one electronic watch, if the input signal is applied to the same electrode on one piezoelectric element, when the alarm is sounding, When you hit the clock to stop the alarm, the drive signal for generating the alarm has already been input to the piezoelectric element, so no other input signal can be input. 1) It is difficult to detect the generated signal.

Therefore, this technique cannot be used to stop the alarm from ringing.

On the other hand, according to Japanese Unexamined Patent Publication No. 53-80263, in order to avoid the above-mentioned problems, switching is performed using another switch.
, because tedious operations such as manual operations are added each time, even a good cutting angle technique becomes half-dead and cannot produce effective results.

The object of the present invention has been made in view of the above-mentioned viewpoints, and is to provide a switch mechanism with a simple structure that is activated by applying an impact even when one function such as an alarm is in operation.

[Means for solving problems]

In order to achieve the above object, the present invention includes a first piezoelectric element fixed to a part of a watch case member for generating an alarm sound;
A second piezoelectric element for detecting an impact applied to a watch case, a detection circuit for detecting a voltage signal generated by the second piezoelectric element, and a detection circuit for outputting only a signal having a level higher than a part of the output signals of the detection circuit. In an electronic clock with an alarm, which has a level discrimination circuit and a clock circuit for performing timekeeping, etc., even when the clock circuit is applying an alarm signal for generating the first (1) alarm sound, ,
The timepiece circuit is operated by an impact signal that detects a voltage signal of the second piezoelectric element generated by an impact force applied to the watch case via the detection circuit and the level discrimination circuit. The second piezoelectric element and the second piezoelectric element are constructed by providing independent electrodes on the upper surface of the same piezoelectric material.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

1 to 5 are drawings of an embodiment of the present invention. FIG. 1 is a sectional view of essential parts showing the sectional structure of the electronic timepiece of this embodiment. 2 is a plan view of the electronic timepiece shown in FIG. 1, viewed from the back cover side with the back cover member shown in FIG. 3 removed. FIG. 3 is a plan view of the back cover member of the electronic timepiece shown in FIG. 1 viewed from the inside as described above.

That is, the electronic timepiece shown in FIG. 1 is completed by stacking the back cover member shown in FIG. 3 on the plan view shown in FIG. 2. Note that the sectional view shown in FIG. 1 corresponds to the AA cross section of the plan view shown in FIG. 2. First, the structure of this embodiment will be explained. In FIGS. 1 to 3, 1 is a watch case body. As shown in FIG. 2, the watch case body 1 has four screw holes 1a at each corner of the watch case body 1 for screwing the back cover plate 2. 2 is the back cover plate. As shown in Fig. 3, a screw hole 2a is provided and the watch case body 1 is fixed to the watch case body 1 with a screw (not shown).3 is a piezoelectric material 6a such as PZT.
This is a piezoelectric element with electrodes formed on its front and back surfaces. In the piezoelectric element B, an electrode 6b is formed almost entirely on the surface in contact with the back cover plate 2, and two independent electrodes 6c and 6d are formed on the other surface as shown in FIG. The piezoelectric element 6 is closely fixed to the back cover plate 2 on the electrode 6b side with adhesive.The upper surface of the electrodes 3C and 3d is provided to prevent electrical short circuit with other parts. In order to an alarm electrode 6a for applying a voltage signal for emitting an alarm sound, and a detection electrode 6b for inputting a voltage signal generated by the piezoelectric element 6.
is provided. 4 is an alarm connection spring for connecting the alarm electrode 6a and the electrode 3C of the piezoelectric element B, and 5 is a detection connection spring for connecting the detection electrode 6b and the electrode 6d of the piezoelectric element 3.

7 is a battery. 8 indicates a clock module. 9 is a battery pressing plate for fixing the battery 7 to the watch module 8. The battery pressing plate 9 has a convex portion 9a for connecting the poles of the battery 7 to the back cover plate 2, and is fixed to the timepiece module 8 by two peninsular portions 9b.

Therefore, when the back cover plate 2 shown in FIG. 3 is superimposed on the electronic watch shown in FIG. and the alarm connection spring 4 provided on the clock module 8 are connected correspondingly, and at the same time, the exposed portion of the insulating member 3e of the electrode 6C provided on the piezoelectric element B is also connected to the detection connection provided on the clock module 8. The corresponding connection with the spring 5 results in a connected state as shown in FIG. In FIG. 1, an alarm signal output from the electronic circuit mounted on the electronic circuit board B is applied from the alarm electrode 6a to the electrode 3C of the piezoelectric element 3 via the alarm connection spring 4. Further, the electrode 3b of the piezoelectric element 6 is short-circuited to the (-)1 electrode of the battery 7 by a battery pressing plate 9 via the back cover plate 2. Therefore, the piezoelectric material 6a of the piezoelectric element B is
An alarm signal voltage is applied by the electrodes 3b and 3C, and distortion is generated due to the piezoelectric phenomenon, which causes the back cover plate 2 to vibrate and generate an alarm sound. On the other hand, due to the strain generated in the piezoelectric material 3a, the electrode 6 of the piezoelectric element 6
In the part where the electrode 6d and the electrode 6d face each other, as is well known, a voltage is generated in response to a change in strain. This is a voltage signal that is generated simultaneously when an alarm is sounding. When an external force shock is applied to the watch case body 1 or the back cover plate 2 in this state, the vibration is transmitted to the piezoelectric element B via the back cover plate 2.The vibration also causes the piezoelectric element 3 to
A voltage signal is generated between the electrode 3b and the electrode 3d. The voltage signal generated at the electrode 3d as described above is transmitted to the electrode 6b of the electronic circuit board 6 connected via the detection connection spring 5. Thereafter, the signal is input to a detection circuit of an electronic circuit mounted on the electronic circuit board 6, which will be described later. Next, Figures 4 and 5
A method of detecting only a voltage signal generated by an external force impact and inputting it to the electronic circuit described above will be described with reference to the drawings.

FIG. 4 is a system circuit diagram, and FIG. 5 is a waveform diagram showing waveforms at each terminal of the system circuit diagram (FIG. 4).

In FIG. 4, 3a, 3b, 3C13d, and 7 indicate the same constituent elements as those explained in FIGS. 1 to 3, so their explanation will be omitted. 10 is an alarm signal amplification circuit, 11
is a detection circuit for detecting a voltage signal generated by the piezoelectric material 6a. The detection circuit 11 includes an electrode 6b of the piezoelectric element B.
It is constituted by a capacitance co due to the area of the piezoelectric material 6a sandwiched between the electrode 6d and the resistor R0. 12 is
This is a level discrimination circuit which inputs the detection signal A of the detection circuit 11, accepts only signals of a certain level or more among the detection signals, and outputs a pulse signal of a certain width or more. The level determination circuit 12 includes a field effect type MO8 transistor (hereinafter referred to as MO8 transistor) that determines the level.
Tr, resistance R1 and capacitance C for determining the pulse width
I and a buffer 12a for pulsing. 16 is a clock circuit. In the clock circuit 13,
An alarm output terminal AL for outputting an alarm signal to the alarm signal amplification circuit 10, a switch input terminal SW, a power terminal ■tlI), and a power terminal Va! are provided.

Now, an alarm signal is output from the alarm output terminal AL of the clock circuit 16 and input to the alarm signal amplification circuit 10. Then, the alarm signal amplification circuit 10 converts the signal into a signal with a relatively constant voltage and high frequency in order to vibrate the piezoelectric element 6. The alarm signal amplification circuit 10 has its output terminal AL0.
When a voltage signal is applied to the electrode 3c of the piezoelectric element 3, distortion occurs in the piezoelectric element 3 due to the piezoelectric effect, and an alarm sound is emitted. At this time, in the detection circuit 11, a voltage signal is generated at the electrode 3d of the piezoelectric element B due to the distortion caused by the alarm sound.

In the detection circuit 11, a bypass filter circuit is formed by a capacitor C6 and a resistor R0. by this,
Signals caused by the piezoelectric element 3 being compressed at low frequencies are cut off, and only signals above a certain frequency are sent to the detection circuit 1.
Since the voltage signal generated by the alarm sound is at a low level, it is not output as the detection signal A. Here, the voltage waveform of the detection signal A is shown in FIG. 5 (4). In FIG. 5, Al is an alarm detection signal by an alarm sound.

The voltage value of the alarm detection signal At is vAL.

Here, a state in which an external force impact is applied will be explained. When an external force shock is applied, the shock is transmitted to the back cover plate 2 shown in FIG. 1 and vibrates, causing distortion in the piezoelectric element B. The impact detection signal generated by this impact is shown in Figure 5 (Al
As shown in OA2.

The voltage value of the impact detection signal A2 is V. It is. Here, to explain the reason why the voltage value V of the shock detection signal A2 is larger than the voltage value VAL of the alarm detection signal A1, it is generally better to convert mechanical energy to electrical energy than to convert electrical energy to mechanical energy. It is known that the conversion efficiency is much better, and for this reason, the voltage value vllK is thicker than the voltage value ■,t.

Therefore, the detection signal A passes the impact detection signal A2 detected by the detection circuit 11 and is input to the level discrimination circuit 12. In the level determination circuit 12, first, the signal is input to the gate terminal of the MOS transistor Tr. In this way, when a signal exceeding the threshold value VB1 is input to the gate of the MOS transistor Tr, the drain-source becomes ON, and the B terminal approaches the VDD power supply which is (+O)V (that is, the fifth As is clear from the figure, the peak value ■1 of the alarm detection signal A1 is the peak value V of the shock detection signal A20.
. It is clear from the previous explanation and experimentally that it is much smaller than the threshold value vth, and it is possible to set it to be smaller than the threshold value vth.Therefore, it is possible to generate a high voltage by applying a small impact to the impact detection signal A2. Can be done. Therefore, the voltage value V of the impact detection signal A2 is set to the critical value V.
V□ at the point when tb crosses from high level to low level
, and conversely, the point of crossing from low level to high level is Vl.
l(2), when the alarm detection signal A1 is input, the source-gate voltage of the MOS transistor Tr is small and is in the OFF state.Next, at the time of V□, the MOS transistor Tr A signal exceeding the threshold value vth is input, the source-gate voltage is turned on, the capacitor C7 is charged, and the B terminal becomes the (0)v level. Next, at time 702, a voltage below the threshold value is applied to the gate of the MOS transistor Tr, and the source-gate becomes OFF. Therefore, capacitor C
The charge stored in I decreases to the (-V) level according to the discharge characteristics of capacitor C8 and resistor R1 (shown in Figure 5 (V of Bl). The voltage waveform shows the appearance as shown in Figure 5.Next, the signal as shown in Figure 5 (Bl) is converted into a pulse by the threshold voltage vth2 of the buffer 12a, and becomes the pulse signal shown in Figure 5. and inputs it to the switch input terminal sW of the clock circuit 13.The pulse width t of the pulse signal needs to have a sufficient time width for the clock circuit 13 to read it, and the pulse width t is determined by each of the resistor R1 and capacitor C1. The clock circuit 13 performs a designated switch operation by reading and inputting a pulse signal.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the voltage signal generated at the electrode 3d of the piezoelectric element 6 due to the impact force applied to the watch case body 1 or the back cover plate 2, that is, the impact detection signal A2, is transmitted to the piezoelectric element 6. is separated from the voltage signal generated at the electrode 3C, that is, the alarm detection signal AI due to vibration distortion caused by the generation of the alarm sound, and is used as a switch signal for the clock circuit 13, so that it can also be used as a switch signal to stop the alarm sound. Can be used. This prevents the user from getting confused when the alarm starts ringing during a meeting (or by tapping the clock, the alarm stops ringing), making it very easy to use with a simple configuration.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention. Figure 1 is a cross-sectional view of an electronic timepiece, Figure 2 is a plan view with the back cover removed, and Figure 3 is a plan view of the back cover. , Figure 4 is a system configuration diagram,
FIG. 5 is a signal waveform diagram showing signal waveforms at each terminal. 1... Watch case body, 2... Back cover plate, 6... Piezoelectric element, 4... Alarm connection spring, 5... Detection connection spring, 6...
Electronic circuit board, 7...Battery, 11...
Detection circuit, 12...Level discrimination circuit. ! a1 Figure 7 JS21Z 3rd leap

Claims (2)

[Claims] (1) A first piezoelectric element fixed to a part of the watch case member for generating an alarm sound, a second piezoelectric element for detecting an impact applied to the watch case, and a voltage signal generated by the second piezoelectric element. In an electronic watch with an alarm, the electronic watch with an alarm has a detection circuit that detects a signal, a level discrimination circuit that outputs only a signal above a certain level among the output signals of the detection circuit, and a clock circuit that performs clock timekeeping, etc. Even when an alarm signal for generating an alarm sound is applied to the first piezoelectric element, the voltage signal of the second piezoelectric element generated by the impact force applied to the watch case is determined by the detection circuit and the level. A switch device for an electronic timepiece, characterized in that the timepiece circuit is operated by an impact signal detected via the circuit. (2) In the switch device for an electronic timepiece according to claim 1, the first piezoelectric element and the second piezoelectric element are provided with a common electrode on the first surface of the same piezoelectric material, and a common electrode is provided on the first surface of the same piezoelectric material; Two independent electrodes are provided on the surface, the first surface is crimped to the watch case, one electrode provided on the second surface is used as the first piezoelectric element, and the other electrode is used as the electrode of the second piezoelectric element. A switch device for an electronic watch characterized by comprising: