JPS6271889A - Electronic timepiece with bathometer - Google Patents

Abstract

PURPOSE:To remove automatically variation in atmospheric pressure, secular changes of a pressure sensor and a pressure value converting circuit, etc., and to display the depth of water having no error by selecting a bathometer function before entry into water. CONSTITUTION:The output of the pressure sensor 1 when a bathometer function selection signal B is outputted is A/D-converted 3 and a detecting circuit 3 decides whether the converted pressure value is normal or not and stores the value as an initial pressure value in a storage circuit 4 when the value is normal. When the value is abnormal, on the other hand, the abnormality is displayed on a display device 9. Then when the storing operation of the circuit 4 is completed, the difference between the pressure value obtained by the A/D conversion 2 and the initial pressure value which is stored 4 is converted by a converting circuit 5 into the depth of water, which is sent to the display device 9.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electronic timepiece with a depth gauge.

[Conventional technology]

In recent years, fast-conductor pressure sensors have become smaller, and by using the electronic circuit of an electronic clock and a display section such as a liquid crystal display, adding a smaller semiconductor pressure sensor only adds space. Now, it has become possible to create a wristwatch with a depth gauge that combines a wristwatch with a depth gauge, which is an essential item for divers, without compromising the image of a traditional wristwatch.

Conventional electronic water depth gauges convert the output of a pressure sensor into a pressure value by A/D conversion, and convert the difference from a preset pressure value of 1 atm into a water depth value for display.

However, the actual pressure underwater is the sum of the weight of the water from the depth to the water surface and the atmospheric pressure at the water surface, and the depth 11 is given by the following equation.

11=c-fall'-(Ph-PO)ρ h: Actual depth of water (m) ρ: Density of water (9/cpo) Pll: Pressure at 11 m of water bed (atmospheric pressure) Po: Atmospheric pressure (water surface (pressure) (atmospheric pressure) Water density ρ differs between pure water and seawater, but it is generally converted to seawater using a depth gauge for Diaper, and can be considered almost constant underwater. However, the atmospheric pressure Po changes. In the conventional example described above, this T'o is fixed at 1 atm, and depending on the change in atmospheric pressure Po, the water depth is displayed as follows.
This results in an error of Δh=0.103ΔPOρ. As a means for removing this error, there is a method known in Japanese Patent Publication No. 60-53874. That is, as shown in FIG. 53, the output from the pressure sensor 21 is converted into a pressure value by the pressure value conversion circuit 22, and the difference from the pressure value at 1 atm is set in advance in the initial value storage circuit 26. is converted into water depth value by the water depth value conversion circuit 24, and displayed on the display device 27.
The water depth value is displayed. Up to this point, it is the same as the conventional example, and the displayed water depth (haha, it includes an error due to the change in atmospheric pressure).

Next, when the external operating member is operated to set a reference for relative water depth measurement, the water depth value at that time is stored in the reference value storage circuit 25 and becomes the reference value. The 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 a display device 27.
is displayed as a relative depth value. If this reference value setting operation is performed at the water surface and the relative water depth is displayed, the above-mentioned error can be eliminated.

[Problem that the invention seeks to solve]

However, this conventional example has the following problems. The first problem is that if you forget to set the reference value under atmospheric pressure, the water depth value based on 1 atm will be displayed, but if you just read the displayed value, you will not be able to tell whether the value is the 1 atm reference water depth or not. It was impossible to determine the depth of the water, and even if an identification mark was displayed on the display, there was a high risk that dippers, who were constantly exposed to danger, would misread it.

The second problem is that even if the reference value setting operation is carried out under -air pressure, if the reference value setting operation is carried out underwater due to an erroneous operation, the display will have even greater errors.

SUMMARY OF THE INVENTION An object of the present invention is to provide a water depth gauge that solves the above-mentioned conventional problems and always displays a correct water depth value in consideration of atmospheric pressure when the water depth is displayed.

[Means for solving problems]

In order to achieve the above object, the present invention has the following configuration. That is, the electronic timepiece with a depth gauge according to the present invention has at least a depth gauge function including a water depth measurement function, a non-water probe function such as a time function, and a pressure sensor and an output from the pressure sensor. A to convert into pressure value /
A D conversion circuit, a writable and readable memory circuit, a pressure value converted by the A/D conversion circuit, and the above-mentioned t? A water depth value conversion circuit that converts the difference between the V141 pressure values stored in the circuit into a water depth value.At the same time as selecting the water depth gauge function, the initial stage stores the pressure value converted by the D/D conversion circuit at that time in the memory circuit. It consists of a changeover switch for controlling the value setting signal and a display device for displaying the selected function.

[Effect]

According to the second configuration (to display the measured water depth value, when the depth gauge function is selected by the external operation member, the initial value setting signal is output from the changeover switch, and this signal causes
The pressure value obtained by converting the output from the pressure sensor at that time by the A/'D conversion circuit is stored in the memory circuit as an initial pressure value. When measuring water depth, the output from the pressure sensor is converted into a water depth value by the water depth value conversion circuit at a predetermined cycle based on the difference between the pressure value converted by the A/D conversion circuit and the initial pressure value stored in the storage circuit. converted. Since the water depth gauge function has already been selected, the water depth value is displayed on the display device.

〔Example〕

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

FIG. 1 is a block diagram of a depth gauge system for an electronic watch with a depth gauge showing a first embodiment of the present invention. Reference numeral 1 denotes a diaphragm type semiconductor pressure sensor, which outputs an analog signal in accordance with pressure. 2 is an A/D conversion circuit that converts the output of the pressure sensor 1 into a digital quantity. The electronic watch with depth gauge in this embodiment measures the water depth value converted according to the time function 7 possessed by a normal digital watch, such as time, calendar, and alarm, and the pressure detected by the pressure sensor 1. Water depth measurement function 6 (water depth measurement system will be described later)
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 each time the signal A is input by the external operating member, the function selected and displayed in the function selection circuit 8 is the time system function or the depth gauge function selection. The signal B causes the depth gauge function 6 to be displayed, and when the function selected and displayed by the function selection circuit 8 is the depth gauge function 6, the time series function selection signal C causes the time series function to be displayed on the display device 9. ing. The depth gauge function selection signal B (hereinafter abbreviated as signal B) is also an initial value setting signal, and the pressure value converted by the A/D conversion circuit 2 from the output of one pressure sensor when signal B is output is abnormal. The abnormal value detection circuit 6 determines whether or not the pressure is normal, and this value is called an initial pressure value and is stored in the memory circuit 4. When abnormal value detection circuit B determines that the abnormal value is abnormal, the display device 9 indicates that the abnormal value is abnormal. When the initial pressure value has been stored in the storage circuit 4-, a signal is activated to activate the A/D conversion circuit 2 at a predetermined period, and the output from the pressure sensor 1 is converted into an A/D converter.
The difference between the pressure value converted by the conversion circuit 2 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.

Abnormal value detection by the abnormal value detection circuit B described above is based on the maximum change in atmospheric pressure, pressure sensors 1 and A, which can change over a long period of time.
/ The judgment is made based on the sum of changes due to changes over time in the D conversion circuit 2, and is a circuit for detecting abnormal values due to system failure.

Further, the underwater detection circuit 11 is a circuit for detecting whether the water depth value converted by the water depth value conversion circuit 5 is positive or not. When this value is positive, the signal A is inputted by the external operation member. Since the changeover switch 1° is controlled not to operate, the time function is not selected underwater, and furthermore, signal B is not output, so the initial pressure value setting will not be set again due to erroneous operation.

With this embodiment, by selecting the depth gauge function before entering the water, changes in atmospheric pressure and changes over time in the pressure sensor and pressure value conversion circuit can be automatically removed to eliminate errors. The correct water depth value will be displayed.

FIG. 2 is a block diagram of a depth gauge/sdem showing a second embodiment of the present invention. In this embodiment, the water depth meter function 6 has a diving information function 12 in addition to the water depth measurement function described in the first embodiment. The diving information function includes functions other than the depth measurement function that are useful when diving, such as a depth alarm function that sets a target depth in advance and outputs an alarm when the measured depth exceeds the set target depth. It is a generic term. Symbols 1 to 7 are the same as in the first embodiment, so their explanation will be omitted. When the function selected by the function selection circuit 8 is the time-related function 7, the external operation member outputs a signal A and a depth gauge function selection signal [1 (hereinafter referred to as signal B) from the changeover switch 10, and the depth gauge Among the functions 6, the underwater detection circuit 11, which is a diving information function, 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 it is a normal value by the abnormal value detection circuit B, the initial pressure value is stored in the storage circuit 4.

When the initial pressure value setting memorization is completed, switch input control circuit 1
3 is activated, and the water depth measurement start signal E (
(hereinafter abbreviated as signal E) is attached. This signal E is input to the D'/J''-A/D converter circuit 2, which is a signal with a constant cycle, and the A/D converter circuit 2 is activated at a predetermined cycle. The difference between the pressure value converted by the D conversion circuit 2 and the initial pressure value stored in the storage circuit 4 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 This is the same as the first embodiment.

In this embodiment, the diving information function required before diving is called up at atmospheric pressure, so the initial pressure value setting that is automatically done by this calling operation is always done at atmospheric pressure. .

Safer. In addition, diving is not necessarily performed immediately after selecting the depth gauge function, and the pressure value conversion circuit is not activated until the depth gauge i1111 start signal is input manually, so power consumption can be reduced.

Fuyoo 1. Changes in atmospheric pressure in retained water cannot be compensated for, but normal diving is short, and changes in atmospheric pressure do not affect minute drops or depth values. The same applies to changes in the pressure sensor over time.

In the embodiment: ' , it is clear that similar effects can be obtained.

[Invention effect]

As is clear from the above explanation, according to the present invention, changes in the atmosphere can be detected by selecting the depth gauge function under atmospheric pressure.
Accurate water depth values can be obtained by removing the temporal changes of the pressure sensor and pressure value conversion circuit, and the display will also display this accurate water depth value (directly only, so it will not be mistaken for other information (use a safe depth meter). This means that it can be provided to

[Brief explanation of drawings]

Figure 1 is a block diagram of a depth gauge system for an electronic timepiece with a depth gauge showing a first embodiment of the present invention, and Figure W2 is a block diagram of a depth gauge system for an electronic timepiece with a depth gauge showing a second embodiment of the invention. , Figure 3 is a block diagram of a conventional electronic depth gauge system. 1...Pressure sensor, 2...A/D
Conversion circuit, 6... Abnormal value detection circuit, 4...
... Memory circuit, 5 ... Water depth value conversion circuit,
6... Depth gauge function, 7... Time system function, 8... Function selection circuit, 9... Display device, 10... Changeover switch, 11...
... Underwater detection circuit, 12 ... Diving information function, 16 ... Switch input control circuit. Figure 1 Figure 2

Claims (1)

[Claims] A pressure sensor, an A/D conversion circuit that converts the output from the pressure sensor into a pressure value, and a memory circuit that can be written and read; A water depth value conversion circuit that converts the difference between the pressure value converted by the A/D conversion circuit and the initial pressure value stored in the storage circuit into a water depth value, and A/D conversion at the same time as the depth meter function is selected. 1. An electronic timepiece with a depth gauge, comprising a changeover switch for controlling an initial value setting signal for storing a pressure value converted by a circuit in the memory circuit, and a display device for displaying a selected function.