JPH0664160B2 - Pressure sensor-Built-in electronic watch - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electronic timepiece having a built-in pressure sensor.

[Prior art]

As the pressure sensor, a resistance change type that converts a pressure change into a resistance value change, a capacitance change type that changes into a capacitance change, an inductance change type that changes into an inductance change, and a crystal that changes into a change in the oscillation frequency of a crystal resonator are used. Oscillation frequency change type. These pressure sensors are widely put to practical use in general measuring instruments, robots and the like. However, when it is applied to a wristwatch, various difficulties arise. That is, it has a small size that can be built into a wristwatch with limited mounting space, can drive at a low voltage using a 1.5V silver battery or a 3V lithium battery, and consumes less current. Low cost, etc. Conventionally, there is nothing that satisfies these conditions, and especially in size, it reaches the wristwatch size only with the sensor unit, and the application of the pressure sensor to the wristwatch is such as water depth measurement, altitude measurement, or atmospheric pressure measurement. While high-value-added functions can be considered, practical application has been difficult.

〔Purpose〕

The present invention solves such a drawback, and its purpose is to be sufficiently small for a wristwatch where only a limited space is allowed, to be able to be driven at a low voltage, to consume a small amount of current, and to have a low power consumption. The purpose is to propose an electronic timepiece with a built-in pressure sensor, which is the cost, and has high-value-added measurement functions such as water depth measurement, altitude condition measurement, or barometric pressure measurement.

〔Overview〕

The electronic timepiece with a built-in pressure sensor of the present invention constitutes a capacitive pressure sensor using a diaphragm, a support, and an electrode of a transparent member, and is attached to the case opening located above the wristwatch display with airtightness. , An oscillating circuit including the capacity of the conductive member and the pressure sensor for electrically connecting the pressure sensor and the electronic circuit inside the case, a signal processing arithmetic circuit for processing the signal from the oscillating circuit, a signal from the signal processing arithmetic circuit And a display means for connecting to the display.

〔Example〕

Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

FIG. 1 is a schematic sectional view of an electronic wrist watch to which the present invention is applied. A capacitive pressure sensor 3 is hermetically attached to an opening of a liquid crystal display device or a watch case 2 located above the display portion 1 by a pointer via an airtight member 4 such as a plastic ring or a rubber packing. Reference numeral 5 is a conductive member such as a coil spring, a leaf spring, leads, a conductive rubber, etc. for electrically connecting the pressure sensor 3 and the electronic circuit 6 inside the timepiece, and an example of the coil spring is shown in the drawing. Reference numeral 7 is a back cover of the watch, and 7a is a packing for keeping airtightness between the case and the back cover. Next, the capacitive pressure sensor 3 will be described in detail with reference to FIGS.

FIG. 2 is a sectional view showing the periphery of the capacitive pressure sensor 3 in an enlarged manner. Reference numeral 8 is a diaphragm, and 9 is a support, which are made of transparent members such as glass, crystal, transparent plastic, and transparent ceramics. Reference numeral 11 is an electrode formed on the diaphragm, and 12 is an electrode formed on the support. These electrodes are transparent electrodes made of SnO ₂ , ITO, In ₂ O ₃ or the like. 14,15 are transparent electrodes 11,12
This is a lead pattern formed on the support in order to electrically connect the conductive member 5 with the conductive member 5, and is transparently formed of SnO ₂ , ITO, In ₂ O _3, or the like.

Reference numeral 10 is a sealing portion for sealing the diaphragm 8 and the support body 9 with a predetermined space therebetween.

FIG. 3 and FIG. 4 are three-dimensional illustrations of the relationship between the diaphragm, the support, the electrodes, and the lead pattern from the electrodes, and the structure in order to make it easier to understand. FIG. 3 (a) shows a diaphragm, (b) shows a support, and (c) shows a state in which both are sealed.

FIG. 4 is a view of FIG. 3c viewed from the back side. The transparent electrodes 11 and 12 are formed on the diaphragm 8 and the support 9 so as to overlap the opposite surfaces in a plane, and form both electrodes of the capacitor. One-dot chain line 13 shown in FIG. 3 (b)
Indicates that the sealing portion 9 reaches up to 13 from the peripheral edge. Further, 14 emitted from the transparent electrode 12 formed on the support is a lead pattern of the transparent electrode 12, and is formed through the peripheral edge of the support to the back side of the support as shown in FIG. . Reference numeral 15 is a lead pattern of the transparent electrode 11 on the diaphragm, and similarly to 14, is formed up to the back side of the support through the peripheral edge of the support. In this case, the transparent electrode 11 and the lead pattern 14 on the diaphragm are the protruding pattern portions (FIG. 3 (a)) provided on a part of the transparent electrode.
16) and the lead pattern 14 are formed so as to overlap each other in a plane, and an electrical connection member is provided there to make an electrical connection. FIGS. 5 and 6 show how the lead pattern 14 and the transparent electrode are electrically connected and sealed.

FIG. 5 (a) shows the lead pattern 14 shown in FIG. 3 (c).
5 shows a cross section of the peripheral portion, and FIG. 5 (b) shows a plane. A connecting member 17 electrically connects the transparent electrode 11 and the lead pattern 15 described above.
In addition, 18 indicates a planar overlapping portion of the transparent electrodes 11 and 12,
Reference numeral 19 indicates a planar overlap between the protrusion 16 of the transparent electrode and the lead pattern 14.

FIG. 6A shows the lead pattern 15 shown in FIG. 3C.
6 shows a cross section of the peripheral portion, and FIG. 6 (b) shows a plane.

As described above, the capacitive pressure sensor 3 of the present invention is shown in FIG.
As described in detail with reference to FIG. 6, as shown in the drawing, the planar shapes of the diaphragm, the support, and the electrodes are not limited to the rectangular shape, but may be any shape such as a round shape and a double circular shape. Conceivable. In addition, the lead pattern is not necessarily drawn in the same direction as the lead pattern that conducts from the electrode on the diaphragm and the lead pattern that conducts from the electrode on the support. Then, both sides may be pulled out at an angle.
Further, FIG. 5 shows an example in which the connecting portion 17 is also located inside the sealing portion and within the planar overlapping portion between the projecting portion 16 of the transparent electrode 11 and the lead pattern 14. As shown in FIG. 7, inside the sealing portion (FIG. 7A), outside the sealing portion (FIG. 7B), the protrusion 16 of the transparent electrode 11 and the lead pattern 15 are formed. Part of it may protrude from the planar overlapping portion of the above (FIG. 7 (c)).

Next, a schematic circuit configuration of the electronic wrist watch configured as shown in FIG. 1 will be described.

FIG. 8 shows a circuit block diagram. 20 is a reference oscillation circuit that oscillates and outputs the reference signal, 21 is a frequency divider that divides the signal from the reference oscillation circuit, 22 is a 1 Hz signal from the frequency divider, and the hour, minute, and second times are counted. A clock counter 23 for obtaining information is a decoder driver circuit for decoding the output of the clock counter and driving the display device, and 24 is a display device. Reference numeral 25 is a CR oscillation circuit including the capacity of the pressure sensor.

Reference numeral 26 is a time reference circuit that defines the time and drive interval for driving the CR oscillation circuit based on the signal obtained by the frequency divider 21, and when the clock switch 27 is input, the drive pulse 32 is set to 25
To drive the CR oscillator circuit. The CR oscillator circuit is the ninth
As shown in the figure, the pressure sensor includes a capacitor 30, a resistor 31, inverters 32 and 33, and a NAND gate 34. Drive pulse
32 is shown in FIG. 10 (a), and the oscillation waveform is shown in FIG. 10 (b).

When the driving pulse becomes high level and is input to the input terminal 35 of the NAND gate 34 of the CR oscillation circuit, CR oscillation occurs. On the other hand, when the drive pulse becomes low level, the output of the NAND gate 34 always becomes low level and oscillation does not occur. The oscillation waveform is input to the counter 28 from the output terminal 36 of the CR oscillation circuit,
The oscillation frequency is counted, and further, the arithmetic processing circuit 29
The count number is converted into a numerical value that physically corresponds to the water depth, atmospheric pressure, etc., and is displayed by the display device 24 via the decoder driver 23.

〔effect〕

According to the present invention, the lead pattern B is formed on the support so that the cross section of the support passes through the peripheral edge of the support so as to wrap the support in order to establish electrical conduction from the transparent electrode formed on the diaphragm. An electrical connection member is provided for achieving electrical conduction with the transparent electrode formed on the diaphragm, and the thickness of the sealing portion for sealing the electrical conduction member to the diaphragm and the support is determined. By adopting the configuration used for this purpose, it is possible to provide an electronic timepiece with a built-in pressure sensor that can maintain the capacitance of the capacitive pressure sensor at an accurate value.

[Brief description of drawings]

1 is a schematic sectional view of an electronic wrist watch to which the present invention is applied. FIG. 2 is an enlarged sectional view of a capacitive pressure sensor according to the present invention. FIGS. 3 (a) to (c) are capacitive types according to the present invention. FIG. 4 is a three-dimensional view of constituent elements of the pressure sensor. FIG. 4 is a three-dimensional view of FIG. 3 (c) viewed from the back side. FIGS. 5 (a) and 5 (b) are electrical connections between the lead pattern and the transparent electrode. FIG. 6 (a) and FIG. 6 (b): Electrical connection between the lead pattern and the transparent electrode, and FIG. 7 (a) (a) ( B), (b) (a) (b),
(C) (a) (b): another embodiment of electrical connection between the lead pattern and the transparent electrode and sealing FIG. 8: Block diagram showing circuit configuration FIG. 9: Pressure sensor Fig.10: A diagram showing the CR oscillator circuit including the capacitance Fig. 10: A diagram showing the drive pulses and oscillation waveforms of the CR oscillator circuit shown in Fig. 9 Capacitive pressure sensor 4 Airtight member 5 Conductive member 6 Electronic circuit 7 Back cover 7a Packing 8 Diaphragm 9 Support 10 Sealing part 11 Transparent electrode 12 ...... Transparent electrode 13 ...... Position where the sealing part reaches from the peripheral edge 14 ...... Lead pattern 15 ...... Lead pattern 16 ...... Projection pattern part provided on a part of the transparent electrode 17 ...... Electrical connection member 18 ...... Planar overlapping part of transparent electrodes 11 and 19 …… Transparent electrode protrusion 16 and lead Plane overlap with pattern 14 …… Reference oscillator circuit 21 …… Divider 22 …… Time counter 23 …… Decoder driver circuit 24 …… Display device 25 …… CR oscillator circuit 26 …… Time reference circuit 27 …… Measurement switch 28 …… Counter 29 …… Arithmetic processing circuit 30 …… Pressure sensor capacity 31 …… Resistance 32 …… Inverter 33 …… Inverter 34 …… NAND gate 35 …… NAND gate 34 input terminal 36… … CR oscillator output terminal

Claims (1)

[Claims] 1. A diaphragm made of a transparent member, a support made of a transparent member, a sealing portion that seals the diaphragm and the support at the entire circumference with a predetermined gap, and the diaphragm and the support. Transparent electrodes formed on the respective opposite surfaces, lead pattern A which is an electrical connection terminal between the transparent electrode and an external electronic circuit, and lead pattern B, and transparent formed on the lead pattern B and the diaphragm. A capacitance change type pressure sensor is formed by an electrical connection member that is arranged between the electrodes and determines electrical connection and determines the thickness of the sealing portion, and the capacitance change type pressure sensor is a digital or analog display. The electronic circuit is mounted airtightly in the case opening located on the upper surface of the part, and the electronic circuit includes an oscillation circuit including the capacitance of the capacitance change type pressure sensor. The lead pattern A is formed on the support so as to radiate to the transparent electrode formed on the support and have a cross-section that surrounds the support through a peripheral edge portion of the support. Built-in pressure sensor, characterized in that a cross section is formed on the support so as to enclose the support through the peripheral edge of the support in order to establish electrical conduction from the transparent electrode formed on the diaphragm. Electronic clock.