JP2682971B2 - Electronic device with depth gauge - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device with a depth gauge having both a non-depth gauge function and a depth gauge function. 2. Description of the Related Art In recent years, miniaturization of semiconductor pressure sensors has progressed,
By combining an electronic circuit owned by an electronic device such as an electronic timepiece with a display unit such as a liquid crystal display,
An electronic water depth meter that integrates the depth gauge function and the non-water depth function, which are essential items for divers, without damaging the image of conventional electronic equipment by simply adding a mounting space for a miniaturized semiconductor pressure sensor. Equipment is becoming possible. An electronic timepiece will be described below as an example of the non-water depth function. [0003] In the conventional electronic water depth gauge, the output of the pressure sensor is A / D converted into a pressure value, and the difference from the preset pressure value at 1 atm is converted into a water depth value for display. It was However, the actual pressure in water is the sum of the weight of water from the water depth to the water surface and the atmospheric pressure on the water surface, and the water depth h is given by the formula shown in Formula 1. Where h: actual water depth (m) ρ: water density (g / cm ³ ) Ph: pressure at water depth hm (atmospheric pressure) Po: atmospheric pressure (pressure on the water surface) (atmospheric pressure) Although the density ρ of water differs between pure water and seawater,
Generally, the depth gauge for divers is converted to seawater and can be considered to be almost constant in the sea. However, the atmospheric pressure P
o changes. In the above-mentioned conventional example, this Po is fixed at 1 atm, and due to the change in atmospheric pressure ΔPo, the water depth display will cause an error as shown in the equation (2). As a means for eliminating this error, Japanese Patent Laid-Open No. Sho 60 has been proposed.
-53874 is available. That is, as shown in FIG. 3, the output from the pressure sensor 21 is converted into a pressure value by the pressure value conversion circuit 22, and the water depth value is calculated from the difference with the pressure value at 1 atmosphere set in the initial value storage circuit 23 in advance. The water depth value is converted by the conversion circuit 24, and the water depth value is displayed on the display device 27. The process up to this point is the same as that of the conventional example, and the displayed water depth value includes an error due to the change in atmospheric pressure. Next, when the external operating member 28 is operated to set the reference for measuring the relative water depth, the water depth value at that time is stored in the reference value storage circuit 25 and becomes the reference value.
After that, the relative water depth value conversion circuit 26 displays the difference between the reference value and the water depth value converted by the water depth value conversion circuit 24 on the display device 27 as a relative water depth value. If the reference value setting operation is performed on the water surface and the relative water depth is displayed, the above error can be eliminated. It should be noted that, in FIG. 3, the initial pressure value is determined by the first detection value of the water depth sensor when water is detected by the water sensor, rather than by manually operating the external operating member to store the reference value. There is also a technique to do so, which is described in JP-A-59-18415. However, the conventional example as shown in FIG. 3 has the following problems. The first problem is that if you forget to set the reference value at atmospheric pressure, the water depth value based on 1 atm will be displayed. However, if you just read the displayed value, the value will be relative to the 1 atm reference water depth. Even if the identification mark is displayed on the display device because it is not possible to determine whether the water is deep, there is a high risk of misreading by the diver who is always in danger. The second problem is that even if the reference value setting operation is performed once under the atmospheric pressure, if the reference value setting operation is performed underwater due to an erroneous operation or the like, the display will have a larger error. was there. Further, in the case of the technique disclosed in Japanese Patent Laid-Open No. 59-18415, the water sensor must always be in the detection standby state. This is because if you happen to be in the water while not in the detection standby state, you will be rushed into the water for the amount of time required to reach the detection state, and you must accurately measure the initial pressure value on the water surface. I can't. In order to solve this, it is sufficient to keep the detection standby state at all times, but in this state, the current is always flowing, and the current consumption becomes large, which is a big drawback especially for small electronic devices. The present invention solves the above-mentioned various conventional problems, and in the water depth display state, it always displays the correct water depth value in consideration of the atmospheric pressure, and the water depth meter does not cause an erroneous operation during the water depth measurement. It is intended to provide an electronic device with a built-in electronic device. In order to achieve the above object, the present invention has the following constitution. That has a non-water depth meter functions such as time-based function and a possible depth gauge function of depth measuring, the water depth meter function converts a pressure sensor, the output from the pressure sensor to the pressure value A / D conversion circuit, writable / readable storage circuit, water depth value conversion circuit
It also has a depth gauge function circuit with a dive information function circuit.
In addition, a switching signal between the non-depth gauge function and the depth gauge function is set.
Output changeover switch and machine that functions according to the changeover signal
Function selection circuit and a display device for displaying the selected function.
In an electronic timepiece with a water depth gauge equipped with
With the circuit has a function for converting the difference between the initial pressure value stored in the storage circuit and converted pressure value by the A / D converter circuit into depth value, the changeover switch is a depth meter function A signal system for storing the pressure value converted by the A / D conversion circuit by the selection signal to be selected in the storage circuit, an underwater detection circuit for detecting whether or not the water pressure is present in the water, and a water depth. Measurement started
And a measurement start signal for
The diving information machine according to the selection signal for selecting the depth gauge function
Display the dive information of the Noh circuit and input the measurement start signal
Together to measure the water depth of the stored pressure values in the storage circuit as the initial pressure value, by the previous SL-water detecting circuit selector switch when detecting that the water actuated by
The feature is to control not to do . In order to display the measured water depth value with the above structure, when the water depth gauge function mode is selected by the external operation member , the changeover switch is operated by a selection signal for selecting the water depth gauge function.
While displaying the diving information, the message from the changeover switch is displayed.
The initial pressure value is stored in the storage circuit according to the number. Depth gauge
At the time of measurement, by inputting the measurement start signal to the memory circuit
When the water depth is measured with the stored pressure value as the initial pressure value
Both detect underwater by underwater detection circuit
And controlling so that the changeover switch does not operate
It is. Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of a water depth gauge system of an electronic timepiece as a typical example of the electronic equipment with a water depth gauge showing the first embodiment of the present invention. Reference numeral 1 is a diaphragm-type semiconductor pressure sensor, which outputs a signal in an analog manner according to the pressure. Reference numeral 2 is an A / D conversion circuit for converting the output of the pressure sensor 1 into a digital quantity. The electronic timepiece with a water depth gauge in the present embodiment is converted according to the time system function 7 as a non-water depth system function unit possessed by a normal digital timepiece such as time, calendar, alarm and the pressure detected by the pressure sensor 1. It has a depth gauge function 6 (a depth measurement system will be described later) which is a depth gauge function part for measuring the depth value, and the function selected by the function selection circuit 8 is displayed on the display device 9. The function selection circuit 8 is activated by the signal output from the changeover switch 10, and the signal A generated by the external operating member is used.
When the function selected and displayed in the function selection circuit 8 is the time system function 7 for each input of, the depth gauge function 6 is selected by the depth gauge function selection signal B, and the function selected and displayed in the function selection circuit 8 is changed. When the water depth meter function 6 is used, the time-related functions are displayed on the display device 9 by the time-related function selection signal C. The water depth gauge function selection signal B (hereinafter abbreviated as signal B) is also an initial value setting signal, and the output from the pressure sensor 1 when the signal B is output is abnormal due to the pressure value converted by the A / D conversion circuit 2. It is determined by the abnormal value detection circuit 3 whether or not there is, and if it is a normal value, this value is called an initial pressure value and stored in the storage circuit 4. If the determination of the abnormal value detection circuit 3 is abnormal, the display device 9 indicates that it is abnormal.
When the storage of the initial pressure value in the storage circuit 4 is completed, the signal D for operating the A / D conversion circuit 2 is activated at a predetermined cycle, and the output from the pressure sensor 1 is converted by the A / D conversion circuit 2. The difference between the pressure value and the initial pressure value stored in the storage circuit 4 is converted into a water depth value by the water depth value conversion circuit 5, and the value is displayed on the display device 9. The detection of the abnormal value by the abnormal value detection circuit 3 described above is based on the sum of the maximum change amount of the atmospheric pressure that can change over a long period of time and the change amount of the pressure sensor 1 and the A / D conversion circuit 2 over time. It is a circuit for detecting an abnormal value due to a system failure. Further, the underwater detection circuit 11 is a water depth value conversion circuit 5
This is a detection circuit for detecting whether or not the water depth value converted by is positive, and when water pressure is applied, this value becomes positive and it is possible to detect that the water is in water. When this value is positive, the changeover switch 10 is controlled so as not to operate even if the signal A is input by the external operating member, so the time system function is not selected in water, let alone the signal B is output. Since it is not performed, the initial pressure value setting will not be reset again by an erroneous operation. According to the present embodiment, by selecting the water depth meter function performed before entering water, changes in atmospheric pressure and changes with time in the pressure sensor and the pressure value conversion circuit are automatically removed. The correct depth value without error is displayed, and the underwater detection circuit that operates by the output signal of the depth gauge function unit prevents the switch from operating even if the changeover switch is operated when the depth gauge is underwater. It is possible to prevent malfunction. FIG. 2 is a block diagram of a depth gauge system showing a second embodiment of the present invention. In the present embodiment, the depth gauge function 6 as the depth gauge function unit has a diving information function 12 in addition to the depth measurement function described in the first embodiment. The dive information function sets a target water depth in advance, and when the measured water depth exceeds the set target water depth, it has a function to output an alarm. It is a generic term. The symbols 1 to 7 are the same as those in the first embodiment, and therefore their explanations are omitted. When the function selected by the function selection circuit 8 is the time system function 7 which is the non-water depth system function, the signal A by the external operating member causes the changeover switch 10 to select the depth gauge function selection signal B.
(Hereinafter referred to as signal B) is output, and the diving information function 12 which is the diving information function of the depth gauge function 6 is selected and displayed on the display device 9. This signal B is also an initial pressure value setting signal as in the first embodiment, and when the abnormal value detection circuit 3 has a normal value, the initial pressure value is stored in the memory circuit 4. The initial pressure value memory is activated switch input control circuit 13 when complete, receives an external operation member such as by depth measuring start signal E (hereinafter abbreviated as signal E).
By this signal E, the display device 9 switches the display signal from the diving information function 12 to the display signal from the water depth value conversion circuit 5 by the function selection circuit 8, and at the same time, D, which is a signal having a constant cycle, is A / D. The pressure value converted by the A / D conversion circuit 2 by the water depth value conversion circuit 5 and the initial pressure value stored in the storage circuit 4 are input to the conversion circuit 2 and the A / D conversion circuit 2 operates at a predetermined cycle. Is converted into a water depth value and displayed on the display device 9. The time-system function selection signal C and the underwater detection circuit 11 are the same as those in the first embodiment. According to the present embodiment, not only the accurate initial pressure value is obtained and no malfunction occurs, but also the diving information function required before diving is called in atmospheric pressure. The automatic setting of the initial pressure value is always performed at atmospheric pressure, which is safer. Further, the diving action is not always performed immediately after the depth gauge function is selected, and since the pressure conversion circuit is not operated until the depth measurement start signal E is input, power consumption can be reduced. It should be noted that although changes in atmospheric pressure during diving cannot be corrected, normal diving takes only a short time and changes in atmospheric pressure are minute, so the depth value is not affected. The same applies to changes over time in the pressure sensor. In the embodiment, the initial pressure value is stored when the water depth gauge function is selected from the time-of-day function, but the same effect can be obtained as long as it is the state of the non-water depth gauge function including the non-display state in addition to the time-of-day function. That is clear. As is apparent from the above description, according to the present invention, a change in atmospheric pressure and a change over time in the pressure sensor and the pressure value conversion circuit can be achieved by the operation of selecting the depth gauge function performed at atmospheric pressure. can obtain an accurate initial pressure value removed, displayed and only accurate depth values for measuring based on the initial pressure value is displayed. Moreover, it will not be misread as other information, and since the changeover switch sets the initial pressure value by the signal that selects the depth gauge function, it is not necessary to keep an eye on the signal until the initial pressure value is set. The current consumption can be reduced, and it has a great effect as a small electronic device with a depth gauge. Moreover, since the switch for mode switching and the switch for setting the initial pressure value are made common, an extra switch can be omitted, which is more effective for a small device. Furthermore, the depth gauge function mode can be controlled by an external operating member.
When you select, the dive information is displayed first to display the dive information.
The reading and input of information is reliable, and at the time of water depth measurement
Starts water depth measurement by inputting a measurement start signal
Also the measuring operation to be ensured to, also, by detecting that the depth gauge function is started reliably measured, the water detecting circuit as the selector switch detects does not operate that depth gauge is in the water Since it is provided, it is possible to provide a safe electronic device with a depth gauge without causing malfunction.
Can Ru.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a water depth gauge system of an electronic timepiece with a water depth gauge showing a first embodiment of the present invention. FIG. 2 is a block diagram of a water depth gauge system of an electronic timepiece with a water depth gauge showing a second embodiment of the present invention. FIG. 3 is a block diagram of a conventional electronic depth gauge system. [Explanation of Codes] 1 Pressure sensor 2 A / D conversion circuit 3 Abnormal value detection circuit 4 Memory circuit 5 Water depth value conversion circuit 6 Water depth function 7 Time system function 8 Function selection circuit 9 Display device 10 Changeover switch 11 Underwater detection circuit 12 Diving information function 13 Switch input control circuit

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Kuniichi Mochida               6-12 Hommachi, Tanashi City, Tokyo               Dung Watch Co., Ltd. Tanashi Factory                    Examiner Kazuhito Ijima                (56) References JP-A-59-18415 (JP, A)                 JP-A-57-101786 (JP, A)                 US Patent 4533256 (US, A)

Claims (1)

(57) [Claims] Has a non-water depth meter functions such as time-based function and a possible depth gauge function of depth measuring, the water depth meter function converts a pressure sensor, the output from the pressure sensor to a pressure value A / D
Conversion circuit, writable and readable memory circuit, water depth change
It has a depth gauge function circuit with a conversion circuit and a diving information function circuit.
And, also, a changeover switch which outputs a switching signal of the the non-water depth meter function the depth gauge function, a function selection circuit functioning by said switching signal, and a display device for displaying the selected function In an electronic timepiece equipped with a water depth gauge, the water
The depth value conversion circuit uses the pressure converted by the A / D conversion circuit.
Difference between the force value and the initial pressure value stored in the memory circuit
Has a function of converting the depth value, the the selection signal the change-over switch selects the depth gauge function A /
A signal system for storing the pressure value converted by the D conversion circuit in the storage circuit, an underwater detection circuit for detecting whether or not it is underwater by detecting the water pressure, and water depth measurement.
A measurement start signal for starting is provided, the switching Sui
The dive by selecting signal
The diving information of the information function circuit is displayed, and the measurement start signal is displayed.
The selector switch when detecting that together, there by the previous SL-water detecting circuit in water to measure the water depth of the stored pressure values in the storage circuit as the initial pressure value by the input of
An electronic device with a water depth gauge, characterized in that it is controlled so as not to operate .