JP2007184796A - Portable terminal device with water leak detection function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a water leak detection function by using in common a part of a mechanism equipped in a portable terminal device. <P>SOLUTION: Water leak detecting terminals 25, 26 are provided at positions required to detect a water leak, as a part of a printed circuit board for detecting depression of a key of a portable telephone. The detecting terminal 25 is connected to an output port 23 of a signal output part 21 which outputs the signals of a matrix circuit for detecting key depression, and the detecting terminal 26 is connected to an input port 24 of a signal input part 22 which receives the signals of the same matrix circuit. If the area between the detecting terminals 25, 26 gets wet with water, a key signal to be specified by a signal output line and a signal input line connected to the detecting terminals 25, 26 is inputted to a controller. The controller determines whether the inputted key signal is a normal key input or a signal from the water leak detecting terminal, by the time duration of the input signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a portable terminal device such as a cellular phone having a water wetting detection function for detecting that water has entered the casing due to submersion or the like.

  Current mobile phones store data such as telephone numbers, names, addresses, and e-mail addresses. However, many users do not back up such data. Therefore, when the mobile phone is submerged, the above data is often lost. In order to deal with such a case, there is an approach of improving the waterproof performance of the mobile phone itself. However, since there are various operating parts (for example, key operation part, battery cover, hinge part, earphone jack cover, etc.), it is difficult to achieve perfect waterproofing.

  Conventionally, as means for detecting water that has entered the casing due to water wetting (submersion) of a mobile phone, a water wetting detection label (a label printed with ink that oozes when touched by liquid such as water) Alternatively, it can be attached to a printed circuit board in the case, and a window for checking the attached label from the outside of the case is provided in the case, so that the mobile phone can be checked without disassembling it, thereby detecting the wetness of the mobile phone. There is a way to do it.

  In this method, in general, a water wetness detection label partially colored with water-based ink is attached to a white seal at a place where water wettability easily occurs, and water wetness is determined based on ink bleeding. However, the determination based on the degree of bleeding tends to obscure the reference, and the ink is blurred even in a high-humidity environment where it can normally occur, making accurate water wetting determination difficult. Even if water wetness can be determined, information held by the mobile phone due to water wet is highly likely to be lost.

  As a means to solve such problems, when the mobile phone body is submerged, it can be detected instantly, and the power can be cut off and various data stored in the mobile phone can be protected as much as possible. In order to achieve this, for example, Patent Documents 1 and 2 propose a technique for electrically detecting the wetness of a mobile phone.

  In Patent Document 1, a pair of electrodes driven at a constant voltage are arranged at both ends of a mobile phone where water is easily wet, and the mobile terminal device gets wet with water due to submergence or the like. When the water adheres to the bridging state, a weak current that flows due to the conduction between the pair of electrodes is detected, and the detected data is stored in the current detection storage element, so that the wetness of the mobile phone can be electrically And the date and time of occurrence of water leakage can be specified.

  In Patent Document 2, on a printed wiring board in a mobile phone, a first terminal connected to a ground terminal and a water wetting detection port provided in a CPU via a resistor are connected and fixed via a resistor. The second terminal connected to the voltage power source is placed close to the liquid, and the liquid that has entered the wiring board shorts between the two terminals, so that the voltage of the water wetting detection port provided in the CPU is reduced. It is detected that the water level has become lower than a predetermined level, and it is determined that water has been wet. The detection result is stored in the memory, and an alarm is output and the power is turned off.

JP 2002-1111838 A JP 2004-235724 A

  According to the inventions described in Patent Documents 1 and 2, it is possible to accurately and promptly determine the presence or absence of water due to water intrusion that leads to failure without disassembling the mobile phone set, and the determination result The control unit performs processing such as power-off of the mobile phone based on the above, so that various data stored in the mobile phone can be protected as much as possible. For this reason, a dedicated circuit for detecting water wetting must be provided in the mobile phone, which increases the cost of the mobile phone.

  In view of the above problems, the object of the present invention is to realize a water wetting detection function by sharing a part of a circuit that is always provided in a portable terminal device such as a cellular phone, thereby making it inexpensive, simple, and more accurate. An object of the present invention is to provide a water leak detection means capable of performing detection.

  The cellular phone with water wetting detection function of the present invention has a plurality of output ports, a signal output unit for outputting a key press detection signal different for each output port, and a plurality of outputs derived from the plurality of output ports, respectively. Signal output lines, a plurality of signal input lines intersecting the plurality of signal output lines in a grid pattern, a signal input unit having a plurality of input ports respectively connected to the plurality of signal input lines, and the grid pattern A key for connecting the signal output line and the signal input line which are arranged at each intersection position of a plurality of signal lines intersecting with each other and when the key provided at the upper part of the intersection position is depressed at the intersection position A key press detection signal output from the signal output unit to the signal output line is output to the signal input unit via the signal input line intersecting at the intersection position. Ki In a mobile phone having a key operation input unit for outputting information to a control unit, 2 made of a highly conductive material between at least one of the plurality of signal output lines and at least one of the signal input lines It is characterized in that a water wetting detection terminal composed of one set is connected.

  The water wetting detection terminal is disposed at an appropriate position where water that has entered the housing can be detected, such as being disposed on a printed wiring board inside the mobile phone, and is connected in parallel with the key switch. The control unit has a function of identifying the signal input from the signal input unit as either normal key input or water detection.

  Further, the water wetting detection terminal is disposed at an appropriate position where water that has entered the housing can be detected, such as being disposed on a printed wiring board inside the mobile phone, and the plurality of signal output lines and the plurality of signals Among the intersection positions where the input lines intersect, it is possible to connect to an intersection position not used as the key switch.

  In another embodiment of the cellular phone with water wetting detection function of the present invention, each of the plurality of output ports has a plurality of output ports, and outputs a signal for detecting a key press different for each output port. A signal input unit having a plurality of derived signal output lines, a plurality of signal input lines intersecting with the plurality of signal output lines in a lattice shape, and a plurality of input ports respectively connected to the plurality of signal input lines And the signal output line and the signal input that are arranged at each crossing position of the plurality of signal lines crossing in the lattice shape and crossing at the crossing position when a key provided above the crossing position is pressed. A key switch for connecting a line, and outputting a key press detection signal output from the signal output unit to the signal output line to the signal input unit via the signal input line intersecting at the intersection position. Especially In a portable terminal device having a key operation input unit that outputs pressed key information to the control unit, a plurality of signal output lines respectively led from a plurality of output ports of the signal output unit to the signal input unit An input line dedicated to water wetting detection that intersects and an input port dedicated to water wetting detection for inputting a signal from the input line dedicated to water wetting detection are provided, and the plurality of signal output lines and the input dedicated to water wetting detection are provided. It is characterized in that a water wetting detection terminal composed of a pair made of a highly conductive material is connected to at least one intersection between the lines.

  The cellular phone with a water wetting detection function according to the present invention is also configured to perform predetermined control by detecting each crossing position of the plurality of signal lines intersecting in the lattice form from signals input to the plurality of input ports of the signal input unit. The control unit has a function of determining the occurrence of water wetting when a signal input to the input port to which the water wetting detection terminal is connected satisfies a predetermined pattern. Have.

  According to the present invention, since a part of the key press detection circuit is shared with the water wetting detection system, it contributes to the cost reduction of the device as compared with the case where a separate water wetting detection circuit is provided.

  Since the present invention uses a part of the key input / detection system for the water wetting detection function, it can be made as a part of a circuit board pattern, for example, and is inexpensive, simple and highly accurate. It is possible to provide a water leak detection means capable of performing detection.

  In addition, since the basic system of the present invention uses a key input / detection system, all of the key ports that can identify a predetermined signal pattern that can be used to determine the occurrence of water wetting are also used as the water wetting detection function. Therefore, it is easy to increase the number of water wetting detection locations, and it is possible to improve detection accuracy.

  FIG. 1 is a block diagram showing a circuit configuration of a mobile phone to which the present invention is applied.

  The cellular phone includes an antenna unit 1, a radio unit 2, an audio processing unit 3, a microphone 4, a speaker 5, a control unit 6, a notification unit 7, a buzzer 8, a VIB motor 9, a key operation input unit 10, a display unit 11, and data management. Part 12, memory part 13 and the like. Of these components, the blocks directly related to the present invention are the key operation input unit 10 and the control unit 6. Further, the function as a mobile phone composed of these blocks is well known to those skilled in the art and is not directly related to the present invention, and therefore the detailed configuration and description thereof will be omitted.

  FIG. 2 is a conceptual diagram of a key operation input unit showing the first embodiment of the present invention.

  The signal output unit 21 and the signal input unit 22 are each provided with a plurality of ports. As shown in FIG. 2, the signal lines from the ports of the signal output unit 21 and the signal input unit 22 are arranged in a grid pattern. Then, the terminals of the signal lines are exposed at the crossing positions, and a key having a conductor is arranged so as to straddle the terminals. When those keys are pressed, the conductors held by the keys electrically connect the signal line terminals at the respective intersection positions. The signal output unit 21 outputs different types (contents) of key press detection signals for each output port, and when one of these keys is pressed and the intersection position is electrically connected. The key press detection signal output from the signal output unit 21 to the output port corresponding to the intersection position reaches the input port corresponding to the intersection position of the signal input unit 22.

  The signal input unit 22 determines which key is pressed based on the type (content) of the key press detection signal input from the signal output unit 21 and the port position (number) from which the signal input unit 22 receives the signal. And sent to the control unit 6. Alternatively, the signal input unit 22 sends to the control unit 6 the type (contents) of the key press detection signal input from the signal output unit 21 and the port position (number) information received by the signal input unit 22. The controller 6 determines which key is pressed from the type (contents) of the key press detection signal input from the signal output unit 21 and the port position (number) information from which the signal input unit 22 receives the signal. Determine. The contents so far are well known to those skilled in the art.

  In this embodiment, among these keys, terminals (25, 26) for water wetting detection are connected in parallel with the contact points of the Web key. With this configuration, the web key contact of the key input system is used for water wetting detection. FIG. 3 is a detailed view around the intersection of the “Web & water wet” signal line of FIG.

  In FIG. 3, the terminals 25 and 26 for detecting water wetting are made of a highly conductive metal material, and are provided at desired positions on the printed circuit board as a part of the printed circuit board for the key press detection circuit of the cellular phone. It has been. The detection terminal 25 is connected to the output port 23 of the signal output unit 21 from which the signal of the matrix circuit for detecting key presses is output, and the detection terminal 26 is the input port of the signal input unit 22 that receives the signal of the same matrix circuit. 24. In FIG. 3, the water wetting detection terminals 25 and 26 are shown as being arranged in the vicinity of the contact point of the Web key, but in reality, in the mobile phone physically separated from the contact point of the Web key. It can be arranged at an appropriate position where it is necessary to detect water wetting.

  The water wetting detection terminals 25 and 26 are arranged close to each other. When water adheres across the water wetting detection terminals 25 and 26, the water wetting detection terminals 25 and 26 are brought into conduction. Although theoretical water, that is, “pure water” is non-conductor, it is almost impossible to have pure water in a normal life scene, so it can be regarded as “water = conductor”. Therefore, when water adheres so as to straddle the terminals of the signal lines (water wetting detection terminals 25 and 26 in FIG. 3), the two terminals are electrically connected, and the output port 23 of the signal output unit 21 is connected. The key pressing detection signal emitted from the signal reaches the signal input unit 22 through the input port 24 via the two water wetting detection terminals 25 and 26.

  However, if the two terminals are only electrically connected, it cannot be identified that the web key that was originally assigned is pressed. In addition, there is a possibility of a malfunction due to dust existing inside or a temporary water wetting phenomenon that does not hinder the operation of the mobile phone. Therefore, in this embodiment, in order to determine whether the Web key is pressed or wet, the time during which the signals from the two terminals are continuously connected is measured. If the connected state is longer than the key pressing time set by prediction from the normal key pressing operation time, it is regarded as a wet state, not a Web key pressed, and the control shown in FIG. The unit 6 immediately shuts down its own power source and protects information in the mobile phone. The set time serving as a reference for the determination is not uniquely determined, and can be determined depending on various design conditions, the overall system configuration of the mobile phone, and the like.

  When the cellular phone is turned off (disconnected) and the device is submerged and the inside of the device gets wet, stored data may be reproduced. Therefore, the stored data is protected by detecting water wetting and turning off the power before the function block that controls the information in the actual mobile phone stops functioning due to submersion. At this time, providing a dedicated water wetting detection means as a detection means has a great influence on the manufacturing cost. Therefore, in the present embodiment, as described above, a key pressing detection circuit already used, specifically, Is provided with a water wetting detection pattern / terminal so as to be a circuit connected in parallel with the key detection pattern on the printed circuit board. If the continuity between these terminals can be confirmed for a certain period of time, it is judged as “water wet” and the power supply is forcibly cut to protect data.

  FIG. 4 is a flowchart showing the operation of water wetting detection in this embodiment. The operation of this embodiment will be described below with reference to FIGS.

  The control unit 6 monitors the key input signal from the key operation input unit 10, and when the key input signal is a signal from the Web key that also functions as a wet detection in s11 ("Yes" in s11). In s12, a timer for recording the time of the wet state is initialized (Time = 0), and the timer operation is started in s13. At this time, the count width of the timer is α [ms]. In s14, the signal input from the Web key that is also used to detect water wetting is searched again. It is confirmed whether or not the signal input is maintained in s15. If the input is not maintained ("No" in s15), it is determined as a normal key input, and the assigned key function (Web function). Execute.

  On the other hand, if the input is maintained (“Yes” in s15), it is further determined in s16 whether the timer value exceeds the water wetness determination time (β [ms]). In (Yes in s16), it is determined that water has adhered between the terminals (25, 26) for detecting wetness, and the apparatus is turned off (s17). If not exceeded (“No” in s16), the timer is continuously added (s13), and after the timer count width α [ms], s14 and subsequent steps are executed again. At this time, the count width (unit time) of the timer “α [ms]” and the water wetness determination time “β [ms]” vary depending on the design philosophy and system configuration, but the relationship between “α” and “β” , Α ≦ β.

  Therefore, when the duration of the signal from the Web key is less than α [ms], it is determined that the input is a normal Web key, the Web function is executed, and the duration of the signal from the Web key is β [ms]. When the value exceeds the value, it is determined that the water has been wetted, and the apparatus is turned off.

  In the above embodiment, in order to make the explanation easy to understand, the water wetting detection position (the number of sets of water wetting detection terminals) is set to be one set at the Web key position. Since the key press detection system is also used, for example, a key other than a key assigned with a special function such as “long press” can play a role of water wetting detection. In order to improve the wetness detection accuracy, it is more desirable to perform parallel detection at a plurality of positions.

  FIG. 5 is a conceptual diagram of a key operation input unit showing the second embodiment of the present invention.

  Although the basic configuration of this embodiment is the same as that of the first embodiment, in this embodiment, an input port 33 dedicated to water wetting detection is set in the signal input unit 32, and this water wetting detection only is used. Through the input signal lines connected to the input port 33, it is possible to set the number of water wetting detection points as many as the number of output ports (35 to 40) of the signal output unit 31. Therefore, it is possible to easily improve the detection accuracy of water wetting. In addition, since the input port is dedicated, in principle it is not necessary to worry about other key inputs, so the time β [ms] for determining water wetting shown in the first embodiment is further shortened. It can be set, and the power of the mobile terminal device can be turned off earlier.

  Further, in FIG. 5, the side keys 1 and 2 are connected to the signal input line connected to the input port 34 at a position intersecting with the signal output lines of the output ports 35 and 36 of the signal output unit 31. The positions intersecting the signal output lines of the output ports 37 to 40 of the signal output unit 31 are not used as key switches, but the signal output lines and signals corresponding to the intersecting positions not used as such key switches are used. A water wetting detection terminal can also be connected between the input lines. Also in this case, since it can be used exclusively for water wetness detection, the time β [ms] for the water wetness determination shown in the first embodiment can be set shorter, and the power of the portable terminal device can be turned off earlier. It becomes possible to do.

  FIG. 6 shows an example of an exploded perspective view of a mobile phone to which the present invention is applied. Usually, the casing of a mobile phone is composed of a front case 41 and a rear cover 42, and the front case 41 is provided with a number of keys (buttons). A printed wiring board 43 is included in the mobile phone. The water wetting detection terminal 44 is arranged at a place where water from the outside of the surface of the printed wiring board 43 may possibly enter first. Then, the wiring from the water wetting detection terminal 44 is connected between the signal output line and the signal input line that intersect the grid pattern of the key operation input unit 10.

  When water entering the mobile phone case is detected at any place where the water wetting detection terminal 44 of the printed wiring board 43 is disposed, a signal output line connected to the water wetting detection terminal 44 The key signal specified by the signal input line is input to the control unit 6, and the control unit 6 determines whether the input key signal is a normal key input or a signal from the water wetting detection terminal 44, for example. The determination is made according to the flowchart shown in FIG.

  As described above, according to the present invention, the signal for determining the pressed key that is output from the key signal output unit for determining the key signal is also used as the signal for detecting water wetting. Can be realized at low cost, and the number of water wetting detection terminals can be easily increased, so that highly accurate water leak detection can be realized.

It is a block diagram which shows the circuit structure of the mobile telephone to which this invention is applied. It is a conceptual diagram of the key operation input part which shows the 1st Embodiment of this invention. FIG. 3 is a detailed view of the vicinity of an intersection of “Web & water” of the signal line shown in FIG. 2. It is a flowchart which shows the operation | movement of the water wet detection in this embodiment. It is a conceptual diagram of the key operation input part which shows the 2nd Embodiment of this invention. It is a disassembled perspective view of the mobile phone to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2 Radio | wireless part 3 Audio | voice processing part 4 Microphone 5 Speaker 6 Control part 7 Notification part 8 Buzzer 9 VIB motor 10 Key operation input part 11 Display part 12 Data management part 13 Memory part 21 Signal output part 22 Signal input part 23,35 -40 Output port 24, 33, 34 Input port 25, 26 Wet detection terminal 41 Front case 42 Rear cover 43 Printed circuit board 44 Wet detection terminal

Claims (10)

A signal output unit having a plurality of output ports and outputting different key press detection signals for each output port, a plurality of signal output lines respectively derived from the plurality of output ports, and the plurality of signal output lines A plurality of signal input lines intersecting with each other in a grid, a signal input unit having a plurality of input ports respectively connected to the plurality of signal input lines, and at each intersection position of the plurality of signal lines intersecting with the grid A plurality of key switches that connect the signal output line and the signal input line that are arranged and intersect at the crossing position when a key provided at the top of the crossing position is pressed, and from the signal output unit Key operation for outputting pressed key information to the control unit by outputting the key press detection signal output to the signal output line to the signal input unit via the signal input line intersecting at the intersection position Enter A portable terminal device having a part,
Between the intersecting signal output line and signal input line, a water wetting detection terminal composed of a pair made of a highly conductive material is connected, and the key operation input unit is connected to the control unit. A mobile terminal device with a water wetting detection function, wherein a function for identifying normal key input and water wetting detection is added to a signal input from.   The portable terminal device with a water wetting detection function according to claim 1, wherein the water wetting detection terminal is connected between the plurality of intersecting signal output lines and signal input lines.   The portable terminal device with a water wetting detection function according to claim 1 or 2, wherein the water wetting detection terminal is connected in parallel with the key switch.   The water wetting detection terminal is between a signal output line and a signal input line corresponding to an intersection position not used as the key switch among the intersection positions where the plurality of signal output lines and a plurality of signal input lines intersect. The mobile terminal device with a water wetting detection function according to claim 1 or 2, wherein the mobile terminal device is connected to the water.   The mobile terminal with a water wetness detection function according to any one of claims 1 to 4, wherein the water wettability detection terminal is disposed at an appropriate position on a printed wiring board inside the mobile terminal device. Terminal equipment. A signal output unit having a plurality of output ports and outputting different key press detection signals for each output port, a plurality of signal output lines respectively derived from the plurality of output ports, and the plurality of signal output lines A plurality of signal input lines intersecting with each other in a grid, a signal input unit having a plurality of input ports respectively connected to the plurality of signal input lines, and at each intersection position of the plurality of signal lines intersecting with the grid A key switch that connects the signal output line and the signal input line that are arranged and intersects at the intersection position when a key provided above the intersection position is pressed, and outputs the signal output from the signal output unit A key operation input unit that outputs pressed key information to the control unit by outputting the key press detection signal output to the line to the signal input unit via the signal input line intersecting at the intersection position The In the mobile terminal equipment that,
To the signal input unit, an input line dedicated to water wetting that intersects with a plurality of signal output lines respectively derived from a plurality of output ports of the signal output unit, and a signal from the input line dedicated to water wetting detection An input port dedicated to water wetting detection is provided, and a signal output line corresponding to at least one intersection position between the plurality of signal output lines and the water wetting detection input line and an input dedicated to the water wetting detection A portable terminal device with a water wetting detection function, characterized in that a water wetting detection terminal composed of a pair of two made of a highly conductive material is connected between the wires.   The mobile terminal device with a water wetting detection function according to claim 6, wherein the water wetting detection terminal is disposed at an appropriate position on a printed wiring board inside the mobile terminal device.   The control unit performs key input determination control by detecting each crossing position of the plurality of signal lines intersecting in the lattice form from signals input to the plurality of input ports of the signal input unit, and also detecting the water wetting 8. The signal input to the input port to which the terminal is connected has a function of determining and controlling the occurrence of water wetting when a predetermined pattern is satisfied. 2. A portable terminal device with a water wetting detection function according to claim 1.   The control unit includes means for determining that the predetermined pattern is satisfied when a duration time of a signal input to the input port to which the water wetting detection terminal is connected exceeds a predetermined time. The portable terminal device with a water wetting detection function according to claim 8. The said control part has a function which forcibly cuts off the power supply of the said portable terminal device, when the determination of the said wetness generation | occurrence | production is performed, The water-wet detection function of Claim 8 or 9 characterized by the above-mentioned Mobile terminal device.

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