Portable electronic device including capacitive water detection means and method of implementation
First Claim
1. A portable electronic device including powering means for powering electronic circuits including a data processing unit, said electronic circuits being housed in an assembly formed by a case closed by a glass, the device further including a pressure sensor and means for detecting the presence of water capable of producing electric signals to be sent to said data processing unit, said detection means including at least one capacitive sensor including a capacitor, one plate of which is formed by an electrode arranged on an inner region of the case-glass assembly and whose capacitance is capable of varying following a modification in nature of the external medium located directly in contact with an external region of the case-glass assembly opposite the electrode, such as said region coming into contact with water, wherein said pressure sensor operates in at least two powering modes, a first called the surface mode and a second called the dive mode and wherein said detection means are periodically activated to carry out measurements of a quantity representative of the value of the capacitance of said capacitor, said electronic circuits further including means for comparing at least two successive measurements of said quantity and producing an electric signal for activating said dive powering mode in response to a variation in said capacitance between two successive measurements of said quantity higher than a predefined value.
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Accused Products
Abstract
There is described a portable device (1) including in particular a case (2) closed by a glass (3) and containing means for detecting the presence of water (20, 22) in contact with an external region of the assembly formed by the case and the glass. In a preferred embodiment, the means for detecting the presence of water include a plurality of capacitive sensors (20) arranged in a peripheral region of the device (1) so as to undergo a variation in their respective capacitances when the latter is immersed in water. Thus, a quantity characteristic of the capacitance value of each sensor (20) is periodically measured and stored. After each measurement, the new value obtained is compared to the preceding one to detect any variation in the corresponding capacitance. When a part of the capacitive sensors (20) simultaneously see their respective capacitances vary considerably between two measurements, detection of the presence of water is validated.
32 Citations
20 Claims
- 1. A portable electronic device including powering means for powering electronic circuits including a data processing unit, said electronic circuits being housed in an assembly formed by a case closed by a glass, the device further including a pressure sensor and means for detecting the presence of water capable of producing electric signals to be sent to said data processing unit, said detection means including at least one capacitive sensor including a capacitor, one plate of which is formed by an electrode arranged on an inner region of the case-glass assembly and whose capacitance is capable of varying following a modification in nature of the external medium located directly in contact with an external region of the case-glass assembly opposite the electrode, such as said region coming into contact with water, wherein said pressure sensor operates in at least two powering modes, a first called the surface mode and a second called the dive mode and wherein said detection means are periodically activated to carry out measurements of a quantity representative of the value of the capacitance of said capacitor, said electronic circuits further including means for comparing at least two successive measurements of said quantity and producing an electric signal for activating said dive powering mode in response to a variation in said capacitance between two successive measurements of said quantity higher than a predefined value.
- 3. A portable electronic device including powering means for powering electronic circuits including, in particular, a data processing unit, said electronic circuits being housed in an assembly formed by a case closed by a glass, the device further including a pressure sensor and means for detecting the presence of water capable of producing electric signals to be sent to said data processing unit, wherein said pressure sensor is capable of operating in at least two powering modes, a first called the surface mode and a second called the dive mode and wherein means for detecting the presence of water include at least a first and a second capacitive sensor each including a capacitor, one plate of which is formed by an electrode arranged on an inner region of the case-glass assembly and whose capacitance is capable of varying following a modification in nature of the external medium located directly in contact with an external region of the case-glass assembly opposite the electrode, such as said region coming into contact with water, said detection means being periodically activated to carry out measurements of a first, respectively a second quantity representative of the value of the capacitance of said first, respectively said second capacitor, said electronic circuits further including means for comparing at least two successive measurements of said first quantity, respectively said second quantity and producing an electric signal for activating said dive powering mode if the variations respectively in said first and second quantities, between two successive measurements, are simultaneously higher than a predefined value.
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15. A method for detecting the presence of water in contact with a portable electronic device including powering means for powering electronic circuits including, in particular, a data processing unit, said electronic circuits being housed in an assembly formed by a case closed by a glass, a pressure sensor operating in at least two powering modes, a first called the surface mode and a second called the dive mode, the device further including detection means capable of producing electric signals to be sent to said data processing unit, said means for detecting the presence of water including at least one capacitive sensor including a capacitor, one plate of which is formed by an electrode arranged on an inner region of the case-glass assembly and whose capacitance is capable of varying following a modification in the nature of the external medium located directly in contact with an external region of the case-glass assembly opposite the electrode, such as said region coming into contact with water, said detection means being periodically activated to carry out measurements of a quantity representative of the value of the capacitance of said capacitor, the method including the periodic steps of:
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a) measuring the value of said quantity;
b) calculating, at each new measurement of said quantity, the variation between its new value and the preceding value;
c) activating the dive powering mode if said variation has a higher value than a predefined value or, if not, starting at step (a) again during the next period. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification