JP2012222858A - Portable information device, electronic device, and connection detection mechanism - Google Patents

Abstract

An object of the present invention is to provide a portable information device that is less likely to cause electrochemical corrosion of a terminal side connection terminal even when moisture adheres and can be realized at low cost.
A terminal side connection terminal, an internal circuit including a secondary battery serving as an operating power source, a switch element provided between the terminal side connection terminal and the internal circuit, a control Unit 31, and the control unit 31 applies an intermittent pulse voltage to the detection terminal pin 34 of the terminal-side connection terminal 13, and measures a change in potential of the pulse voltage, whereby the terminal It is detected whether or not a connection terminal of an external device is connected to the side connection terminal 13, and when the connection terminal of the external device is connected to the terminal side connection terminal 13, the switch element 17 is operated. The terminal side connection terminal 13 and the internal circuit 15 are connected.
[Selection] Figure 4

Description

  The present invention relates to a portable information device having a terminal-side connection terminal connected to an external device, an electronic device having a portable information device and an expansion device, and a connection for detecting that the connection terminal of the external device is connected to the connection terminal In particular, the present invention relates to a portable information device, an electronic device, and a connection detection mechanism that can suppress corrosion of the terminal even in a state where moisture is attached to the connection terminal and can obtain high connection reliability.

  In recent years, so-called mobile use portable information devices such as notebook personal computers, PDAs (Personal Digital Assistants), navigation systems, mobile phones, and portable game devices are becoming widespread. In addition, as portable devices used at home, such as intercoms, handset of fixed telephones, and small television receivers, many portable use portable information devices that can be used anywhere are used.

  A rechargeable secondary battery is used as a power source for a mobile information device for mobile use or portable use. The cradle is used to charge the secondary battery and transfer data between the portable information device and another electronic device, for example, displaying image data of the portable information device on a stationary television device. An extension device called is used.

  The cradle has a receiving structure on which a portable information device can be placed, and by mounting the portable information device on the cradle, a terminal side connection terminal provided on the portable information device and a device side connection terminal provided on the cradle are provided. A charging current for charging the secondary battery of the portable information device is supplied from the cradle, and necessary information is transferred between the portable information device and the cradle.

  Along with the advancement of waterproof technology, portable information devices that can be used in environments that are subject to rainwater and severe environments with large temperature changes that cause condensation have appeared. Conventionally, in a portable information device that can be used under such severe environmental conditions, it is common to cover the terminal-side connection terminal with a waterproof cover. However, depending on the application of the portable information device, the device may be quickly mounted on the cradle to transfer the internal data, so the terminal connection terminal must always be exposed without being covered with a waterproof cover. There is something.

  In such portable information devices with terminal-side connection terminals exposed, moisture adheres to the exposed terminal pins, causing electrochemical corrosion, increasing the surface resistance of the terminal pins, and connecting the terminal-side connection terminals to the cradle. When connected to the device side connection terminal, there is a problem that normal electrical connection cannot be secured.

  As a means for solving such a problem, in a portable information device that operates with a secondary battery, the current is not reversed between the terminal pins of the terminal side connection terminal between the secondary battery and the terminal side connection terminal. A diode is placed, a magnet is placed in the housing of the portable information device, and a magnetic sensor having a switch that can be operated by magnetism placed in the cradle detects that the portable information device is mounted on the cradle and generates a charging current. The technique of supplying has been proposed (see Patent Document 1).

JP 2004-342611 A

  In the technology described in Patent Document 1, since the diode prevents the current from flowing backward between the terminal-side connection terminal and the secondary battery, the terminal-side connection terminal provided exposed to the portable information device Even when a conductive fluid such as moisture adheres to the electrode, current from the secondary battery does not flow to the terminal pin, and electrochemical corrosion of the terminal pin can be prevented. In addition, when the magnetic sensor of the cradle senses the magnetic force of the magnet provided in the portable information device and the portable information device is mounted on the cradle, a charging current flowing in the forward direction of the diode is applied. The secondary battery of the portable information device can be charged without any trouble.

  However, since the conventional portable information device described in Patent Document 1 is configured to detect on the cradle side that the portable information device is mounted on the cradle, a switch for supplying a detection mechanism and a charging current to the cradle. It becomes necessary to provide a mechanism, and the structure of the cradle becomes complicated.

  Further, since magnetic means is used as means for detecting that the portable information device is mounted on the cradle, it is necessary to provide an expensive magnet and a magnetic detection element such as a Hall element. It cannot be avoided that the cost of the system increases. Furthermore, when a metal is used as the casing of the portable information device, the magnetic field of the magnet inside the portable information device casing cannot be detected by the cradle, so that the portable information device is used in a harsh environment. Nevertheless, there is a restriction that a high-strength metal casing cannot be used.

  The present invention solves such a problem of the prior art, and even when moisture adheres to the portable information device, the terminal side connection terminal is less likely to be electrochemically corroded and can be realized at low cost, and the portable information device. It is an object of the present invention to obtain an electronic device including an extension device and a connection detection mechanism that can detect that a connection terminal is connected to an external connection terminal.

  In order to solve the above problems, a portable information device of the present invention is provided between a terminal-side connection terminal, an internal circuit including a secondary battery as an operation power supply, and the terminal-side connection terminal and the internal circuit. A switch element; and a control unit, wherein the control unit applies an intermittent pulse voltage to the detection terminal pin of the terminal-side connection terminal, and measures a change in potential of the pulse voltage, It is detected whether or not a connection terminal of an external device is connected to the terminal side connection terminal. When the connection terminal of the external device is connected to the terminal side connection terminal, the terminal is operated by operating the switch element. A side connection terminal and the internal circuit are connected.

  The electronic device of the present invention includes a terminal side connection terminal, an internal circuit including a secondary battery as an operation power supply, a switch element provided between the terminal side connection terminal and the internal circuit, and a control unit. A portable information device, and a device-side connection terminal connected to the terminal-side connection terminal of the portable information device when the portable information device is mounted, at least through the device-side connection terminal. An expansion device that supplies a charging current for charging the secondary battery of the information device, and the control unit of the portable information device applies an intermittent pulse voltage to the detection terminal pin of the terminal-side connection terminal. Then, by measuring a change in potential of the pulse voltage, it is detected whether the device side connection terminal of the extension device is connected to the terminal side connection terminal, and the device side connection is connected to the terminal side connection terminal. Terminals are connected If you are, characterized in that by operating the switching element connecting the internal circuit and the terminal-side connection terminal.

  Furthermore, the connection detection mechanism of the present invention includes an output unit that outputs an intermittent pulse voltage applied to the detection terminal pin of the terminal side connection terminal, and a predetermined time after the output unit applies the pulse voltage. A measurement unit that measures the potential of the detection terminal pin after elapses, and a detection that detects whether the terminal-side connection terminal is connected to a connection terminal of another device based on the potential measured by the measurement unit And a portion.

  In the portable information device of the present invention, the control unit detects whether or not the connection terminal of the external device is connected to the terminal side connection terminal by applying an intermittent pulse voltage to the detection terminal pin. For this reason, even when moisture or the like adheres to the exposed terminal-side connection terminals, electrochemical corrosion hardly occurs, and a portable information device with high connection reliability can be realized at low cost.

  In the electronic device of the present invention, the control unit of the portable information device detects that the device side connection terminal of the expansion device is connected to the terminal side connection terminal by applying an intermittent pulse voltage, Connect the side connection terminal to the internal circuit. For this reason, an electronic device including a portable information terminal with high connection reliability that can hardly be corroded even when moisture or the like adheres to the terminal-side connection terminal and an expansion device that can charge it is obtained at low cost. be able to.

  Furthermore, the connection detection mechanism of the present invention is measured by the output unit that applies intermittent pulse voltage to the detection terminal pin of the terminal side connection terminal, the measurement unit that measures the potential of the detection terminal pin, and the measurement unit. And a detection unit that detects whether the terminal-side connection terminal is connected to a connection terminal of another device based on the potential. For this reason, the average current amount of the current applied to the detection terminal pins in order to detect the connection can be reduced, and corrosion of the terminal side connection terminals can be effectively suppressed.

It is a perspective view which shows the state which mounted the notebook computer concerning embodiment of this invention in the cradle. It is a top view which shows the bottom face in which the terminal side connection terminal part of the notebook computer concerning embodiment of this invention is provided. It is a perspective view which shows the structure of the cradle in which the notebook computer concerning embodiment of this invention is mounted. It is a block diagram which shows the circuit structure of the notebook personal computer and cradle concerning embodiment of this invention. It is a block diagram which shows the structure of the connection detection mechanism in the control part of the notebook computer concerning embodiment of this invention. It is a figure which shows the voltage waveform applied to the detection terminal pin of a terminal side connection terminal part in the notebook computer concerning embodiment of this invention. It is a figure explaining the change of the electric potential of the detection terminal pin of a terminal side connection terminal part in the notebook computer concerning embodiment of this invention. It is a figure which shows the effect which can suppress the corrosion of the terminal pin of a connection terminal by applying a pulse-form voltage to a detection terminal pin.

  A portable information device of the present invention includes a terminal side connection terminal, an internal circuit including a secondary battery as an operation power supply, a switch element provided between the terminal side connection terminal and the internal circuit, and a control unit. The controller is configured to apply an intermittent pulse voltage to the detection terminal pin of the terminal side connection terminal and measure a change in potential of the pulse voltage to connect the external device to the terminal side connection terminal. It is detected whether or not a connection terminal is connected, and when the connection terminal of the external device is connected to the terminal side connection terminal, the terminal side connection terminal and the internal circuit are operated by operating the switch element. Connect.

  Since the portable information device of the present invention has the above-described configuration, the voltage applied to the detection terminal pin of the terminal-side connection terminal is intermittently pulsed. Even when is attached, the average amount of current flowing between the terminal pins of the terminal-side connecting terminal can be kept low, and the electrochemical corrosion of the terminal pins can be suppressed. For this reason, the portable information apparatus provided with the terminal side connection terminal which has high conduction | electrical_connection reliability between the connection terminals of an external apparatus can be obtained. In addition, since it is possible to detect whether or not the connection terminal of the external device is connected to the terminal side connection terminal without using magnetic means, it is possible to use a metal housing at low cost. A portable information terminal can be realized.

  In the portable information terminal according to the present invention, the pulse voltage preferably has an on-time duty ratio of 1/1000 or less, and the pulse voltage has an on-time duty ratio of 10,000 minutes. More preferably, it is 1 or less. By doing in this way, the average electric current amount which flows into the detection terminal pin of a terminal side connection terminal can be brought close to a non-energized state, and the electrochemical corrosion of a terminal pin can be suppressed effectively.

  Moreover, it is preferable that the said control part measures the change of the electric potential of the said pulsed voltage using the said detection terminal pin to which the said pulsed voltage was applied. By doing in this way, it is possible to detect whether or not the connection terminal of the external device is connected to the terminal side connection terminal with one detection terminal pin, so the connection terminals of both the terminal connection terminal and the external device can be detected. Miniaturization can be realized.

  An electronic device according to the present invention includes a terminal-side connection terminal, an internal circuit including a secondary battery as an operation power supply, a switch element provided between the terminal-side connection terminal and the internal circuit, and a control unit. A portable information device, and a device-side connection terminal connected to the terminal-side connection terminal of the portable information device when the portable information device is mounted, and at least the portable information device via the device-side connection terminal An extension device that supplies a charging current for charging the secondary battery, and the control unit of the portable information device applies an intermittent pulse voltage to the detection terminal pin of the terminal-side connection terminal, By measuring the change in potential of the pulse voltage, it is detected whether the device side connection terminal of the extension device is connected to the terminal side connection terminal, and the device side connection terminal is connected to the terminal side connection terminal. It is connected The case, connecting the internal circuit and the terminal-side connection terminal by operating the switch element.

  Thus, in the electronic device of the present invention, the control unit of the portable information device applies an intermittent pulse voltage with a small average current amount, and the device side connection terminal of the expansion device is connected to the terminal side connection terminal. Can be detected and the terminal side connection terminal and the internal circuit can be connected by operating the switch element. For this reason, it has a portable information terminal with high connection reliability that is unlikely to cause corrosion of the terminal pins even if moisture adheres to the terminal-side connection terminal, and an expansion device that can be easily charged by mounting it. An electronic device can be realized. In addition, since the configuration of the expansion device can be simplified without using magnetic means that cause high costs, an electronic device can be realized at a low cost, and a metal case can be used as a casing of a portable information device. Materials can also be used.

  In the electronic device of the present invention, the device-side detection terminal pin of the device-side connection terminal of the extension device connected to the detection terminal pin of the terminal-side connection terminal is grounded, and the control of the portable information device It is preferable that the unit measures a change in potential of the pulse voltage using the detection terminal pin to which the pulse voltage is applied. By doing in this way, it can be surely detected by the detection terminal pin that the terminal side connection terminal is connected to the connection terminal of the expansion device, and the terminal side connection terminal and the device side connection terminal can be made small at the same time. And further downsizing of the electronic device can be realized.

  Furthermore, the connection detection mechanism of the present invention includes an output unit that outputs an intermittent pulse voltage applied to the detection terminal pin of the terminal side connection terminal, and a predetermined time after the output unit applies the pulse voltage. A measurement unit that measures the potential of the detection terminal pin after elapses, and a detection that detects whether the terminal-side connection terminal is connected to a connection terminal of another device based on the potential measured by the measurement unit Department.

  With this configuration, the connection detection mechanism of the present invention can reduce the average amount of current applied to the detection terminal pin of the terminal-side connection terminal for connection detection. For this reason, even when moisture or the like adheres to the terminal-side connection terminal, the electrochemical corrosion of the terminal pin can be effectively suppressed.

  Further, it is preferable that the output unit forcibly applies a Lo level potential to the detection terminal pin after the measurement unit measures the potential of the detection terminal pin. By doing in this way, even when the connection terminal of another apparatus is not connected to the terminal side connection terminal, it is possible to avoid the occurrence of a measurement error by stabilizing the potential of the detection terminal pin.

  Further, in the detection unit, the terminal side connection terminal is connected to the connection terminal of the external device when the potential of the measurement terminal pin measured by the measurement unit is continuously at the Lo level three times. It is preferable to judge that. By doing so, it is possible to realize a practically sufficient response and avoidance of detection errors.

  Hereinafter, as an embodiment of the electronic device according to the present invention, a mobile personal computer as a portable information device, a cradle as an expansion device that supplies a charging current to the mobile personal computer and serves as a connection port with other peripheral devices, An example including the above will be described.

  FIG. 1 is a perspective view showing the overall configuration of an electronic device in a state where the mobile personal computer of the present embodiment is mounted on a cradle.

  The electronic device 100 according to this embodiment includes a mobile personal computer 10 and a cradle 20. As shown in FIG. 1, by mounting the mobile personal computer 10 on the cradle 20, an expansion connector of the mobile personal computer 10 described later and a connection connector of the cradle 20 are connected. For this reason, by mounting the mobile personal computer 10 on the cradle 20, a charging current for charging a secondary battery (not shown), which is an operation power source of the mobile personal computer 10, is supplied via the cradle 20. Data can be transferred by connecting to an external device via an input / output terminal 21 for connecting to an external device such as a USB port, a LAN connector, or a serial connector.

  Note that the mobile personal computer 10 of the electronic device 100 of the present embodiment is illustrated as including the image display surface 11 and the operation buttons 12. However, the form of the mobile personal computer 10 is not limited, and the number of the operation buttons 12 is not limited. The arrangement position and the like are matters to be appropriately designed according to the use. For this reason, the operation buttons may be arranged on a surface different from the surface on which the image display surface 11 of the mobile personal computer 10 is formed, and a keyboard may be provided instead of the operation buttons 12.

  Moreover, although the example which has arrange | positioned the input / output terminal 21 in the side which the image display surface 11 faces as the cradle 20 of the electronic device 100 of this embodiment when the mobile personal computer 10 is mounted was shown. There are no restrictions on the position, number, and contents of the arrangement. For example, video output and audio output terminals can be provided so that an image can be displayed on an external large monitor. Furthermore, the cradle 20 can be provided with an optical disk drive device, a hard disk drive (HDD), and various functions and configurations necessary for improving the use and user convenience.

  FIG. 2 is a plan view showing a bottom surface 10a of the electronic device 100 of the present embodiment when the electronic device 100 is mounted on the cradle 20 shown in FIG.

  As shown in FIG. 2, an expansion connector 13 that is a terminal-side connection terminal for connecting to the cradle 20 is disposed on the bottom surface 10 a of the mobile personal computer 10. The expansion connector 13 includes a plurality of terminal pins 14.

  FIG. 3 is a perspective view showing the cradle 20 of the electronic device 100 of the present embodiment.

  As illustrated in FIG. 3, the cradle 20 according to the present embodiment has a connection connector 23 that is a device-side connection terminal on a mounting surface 22 on which the mobile personal computer 10 is mounted. The connection connector 23 corresponds to the expansion connector 13 of the mobile personal computer 10 in terms of its shape and the arrangement of the terminal pins 24. When the mobile personal computer 10 is mounted on the mounting surface 21 of the cradle 20, the connection connector 23 is provided on the bottom surface 10a of the mobile personal computer 10. The extension connector 13 and the connection connector 23 on the mounting surface 22 of the cradle 20 are fitted and connected.

  FIG. 4 is a block diagram showing a circuit configuration of the electronic apparatus 100 according to the present embodiment.

  As shown in FIG. 4, the electronic apparatus 100 according to the present embodiment is configured such that the mobile personal computer 10 and the cradle 20 are connected to each other by an extension connector 13 and a connection connector 23 that are connection terminals. is doing.

  The mobile personal computer 10 includes a main body circuit 15 that is an internal circuit that functions as a personal computer. In the mobile personal computer 10 of the present embodiment, the main circuit 15 is a personal computer such as a CPU, a circuit for displaying an image, various memories for storing data such as a hard disk drive, a circuit for driving the data, and a circuit related to an interface such as a LAN board. Since this is a circuit group normally provided, a detailed description thereof will be omitted. In FIG. 4, the main circuit 15 is shown as one block for the sake of convenience, but this does not indicate that the main circuit 15 is composed of a single board, but is included in the normal personal computer. The circuit group is merely illustrated as a group.

  In addition, in the electronic device 100 or the mobile personal computer 10 of the present embodiment, the internal circuit is a concept including at least a secondary battery 18 that is a driving power source of the mobile personal computer 10 in addition to the main circuit 15.

  In the mobile personal computer 10 of the present embodiment, switch elements 17 are provided in connection wirings that connect the input / output terminals 16 of the main circuit 15 and the terminal pins 14 of the expansion connector 13, respectively. The controller 31 controls the on / off.

  The control unit 31 detects that the connection connector 23 of the cradle 20 is connected to the expansion connector 13 (corresponding to a connection detection mechanism), and the detection mechanism 32 connects to the expansion connector 13 and the connection connector 23 of the cradle 20. Is connected to the expansion connector 13 and the input / output terminal 16 of the main circuit 15 when the switch element 17 is detected. As the control unit 31 performing such a function, an electronic circuit having a normal control function such as a microcomputer can be used.

  In FIG. 4, the main body circuit 15 and the control unit 31 are shown as separate circuit blocks as circuit blocks in the mobile personal computer 10, but this is functionally different as circuit blocks that perform different functions. It merely indicates that it can be grasped as a thing, and does not indicate that another circuit board is physically configured. For this reason, at least a part of the control unit 31 is not prevented from being formed as a part of the microcomputer chip constituting the main body circuit 15.

  The detection mechanism 32 of the control unit 31 is connected to one detection terminal pin 34 constituting the expansion connector 13.

  The cradle 20 includes a connection connector 23 and a cradle circuit 25.

  The connection connector 23 includes terminal pins 24 each connected to the cradle circuit 25 and is connected to the corresponding terminal pin 14 of the expansion connector 13 of the mobile personal computer 10. When the switch operating unit 33 of the control unit 31 of the mobile personal computer 10 turns on the switch element 17, the main circuit 15 and the cradle circuit 25 are connected via the expansion connector 13 of the mobile personal computer 10 and the connection connector 23 of the cradle 20. Is connected. When the main circuit 15 and the cradle circuit 25 are connected, a charging current for charging the secondary battery 18 of the mobile personal computer 10 is supplied, and data communication between the mobile personal computer 10 and other devices connected to the cradle 20 is performed. Is possible.

  The cradle circuit 25 is provided in accordance with the functions performed by the cradle 20 such as supply of charging current to the mobile personal computer 10, connection to various external memory devices such as monitors, hard disk drives, and Internet lines. The connection terminals, connectors, data conversion circuit, and the like are provided as circuit elements, but the contents thereof can be used as they are, and their illustration and detailed description are omitted. In addition, when the cradle 20 is provided with a hard disk drive or an optical disk drive device, various circuit configurations and various electronic devices required to perform these functions are also included in the cradle circuit 25 in the present embodiment. Is done.

  Further, FIG. 4 shows an example in which the cradle circuit 25 includes an AC cord 26 connected to an external commercial power source. However, the operating power source of the cradle 20 is not limited to a commercial AC power source, and the cradle 20 itself is externally connected. In consideration of the possibility of taking it out and using it, a secondary battery provided in the cradle can be used as a power source.

  The connection connector 23 of the cradle 20 includes device-side detection terminal pins 35 that are connected to the detection terminal pins 34 of the mobile personal computer 10. As shown in the figure, in the electronic device 100 of this embodiment, the device-side detection terminal pin 35 is grounded (GND) inside the cradle 10.

  FIG. 5 is a block diagram illustrating a configuration of a detection mechanism 32 that detects that the connection connector 23 of the cradle 20 is connected to the expansion connector 13 of the mobile personal computer 10 in the electronic device 100 of the present embodiment.

  As shown in FIG. 5, the detection mechanism 32 of the mobile personal computer 10 according to the present embodiment includes an output unit 36, a measurement unit 37, a detection unit 38, a resistor R connected to the output unit 36 and the measurement unit 37, and this. And a capacitor C to be clamped.

  The output unit 36 applies an intermittent pulse voltage. FIG. 6 shows an example of the waveform of the pulse voltage applied by the output unit 36 to the detection terminal pin 34.

  As shown in FIG. 6, the output unit 36 in the mobile personal computer 10 of the present embodiment generates an intermittent pulse voltage having an ON time 42 of 2 μs, a period 43 of 20 ms, and an ON time duty ratio of 1/10000. Applied. Note that the voltage value (V) of the applied voltage is not particularly limited, and the output unit 36 of this embodiment uses 3.3V, which is the operating power supply voltage of the microcomputer on which the detection mechanism 32 is mounted, as it is. Used.

  When the output unit 36 finishes outputting the pulse voltage, for example, after waiting for 1 μs or longer, the output unit 36 connected to the detection terminal pin 34 is disconnected, and instead the measurement unit 37 is connected. Is done. Then, the measurement unit 37 measures the voltage at the detection terminal pin 34.

  FIG. 7 is a diagram illustrating the principle of the detection mechanism 32 that detects that the connection connector 23 of the cradle 20 is connected to the expansion connector 13 of the mobile personal computer 10 in the configuration of the detection mechanism 32 of the present embodiment.

  Reference numeral 41 shown in FIG. 7 is a pulse voltage waveform from the output unit 36 described in FIG.

  Since the pulsed voltage waveform 41 is turned off after the on-time 42 which is 2 μs in the present embodiment, the voltage applied to the detection terminal pin 34 is 0V. As for the signal voltage level in this embodiment, this 0V is the Lo level, and the pulsed voltage potential 3.3V is the Hi level.

  When the detection terminal pin 34 of the expansion connector 13 is connected to the device side detection terminal pin 35 of the connection connector 23 of the cradle 20, the device side detection terminal pin 35 is grounded in the cradle 20, The voltage at the detection terminal pin 34 immediately drops to indicate the Lo level as shown at 44 in FIG. On the other hand, when the detection terminal pin 34 of the extension connector 13 is not connected to the device-side detection terminal pin 35 of the connection connector 23 of the cradle 20, the detection terminal pin 34 is clamped by the capacitor C. The voltage keeps the Hi level without decreasing as shown by 45 in FIG.

  Therefore, after the pulse voltage 41 is applied, in the present embodiment, as described above, for example, after the waiting time 46 of 1 μs or longer has elapsed, the potential of the detection terminal pin 34 is measured, so that the potential becomes the Hi level. In this case, when the connection connector 23 is not connected to the expansion connector 13 and the potential is Lo level, it can be detected that the connection connector 23 is connected to the expansion connector 13.

  As described above, the detection unit 38 of the detection mechanism 32 determines whether the potential of the detection terminal pin 34 measured by the measurement unit 37 is at the Hi level or the Lo level after the predetermined waiting time 46 has elapsed. Thus, it is detected whether or not the connection connector 23 is connected to the expansion connector 13.

  Here, the detection unit 38 of the present embodiment has the connection connector 23 connected to the expansion connector 13 when the potential of the pulse voltage applied by the input unit 36 to the detection terminal pin 34 becomes the Lo level three times in succession. It is determined that they are connected, and a signal is sent to the switch operation unit 33 so that the switch operation unit 33 turns on the switch element 17.

  As described above, when the potential of the detection terminal pin 34 becomes the Lo level three times in succession, it is determined that the connection connector 23 is connected to the expansion connector 13 for the first time with only one signal. This is because there may be a case of malfunction or noise, and there are cases where it is not completely reliable. Even if the signal is received three times, as shown in FIG. 6, the output unit 36 of this embodiment applies a pulse voltage to the detection terminal pin 34 at a cycle of 20 μs. It can be detected in 60 μs after the connection connector 23 is connected, and the practical time lag is not a problem.

  Note that the number of signals required until it is determined that the connection connector 23 is connected to the expansion connector 13 is not limited to three, and the period of the pulse voltage applied by the output unit 36 to the detection terminal pin 34, the expansion connector 13 and the like. The number of necessary signals may be determined appropriately in consideration of the timing of signal processing after the connection connector 23 is connected.

  Further, as shown in FIG. 7, the detection mechanism 32 of the present embodiment is configured so that, after the measurement unit 37 measures the potential of the detection terminal pin 34, for example, after a certain time 47 of 2 to 3 μs has elapsed, the output unit 36 The electric potential of 0V which is Lo level is applied. By doing in this way, in the state 45 in which the connection connector 23 is not connected to the expansion connector 13, it is possible to reset the state in which the detection terminal pin 34 maintains the Hi level potential, and at the next cycle. The detection accuracy when a pulse voltage is applied can be improved.

  Further, in the detection mechanism 32 of the present embodiment, after detecting that the connection connector 23 is connected to the expansion connector 13, a pulse voltage is continuously applied from the input unit 36 to the detection terminal pin 34, and the predetermined time 46. After the elapse of time, the measurement unit 37 continues to detect the potential. When the detection unit 38 detects that the potential of the detection terminal pin 34 measured at the measurement unit 37 has become Hi level, the detection unit 38 determines that the connection between the expansion connector 13 and the connection connector 23 has been canceled, and switches the operation. A signal is sent to the unit 33, and the switch operation unit 33 turns off the switch element 17. In this way, when the connection connector 23 is not connected to the expansion connector 13, the connection between the expansion connector 13 and the main body circuit 15 of the mobile personal computer 10 is canceled.

  FIG. 8 shows experimental results confirming the effect of applying an intermittent pulse voltage in order to detect that the connection connector 23 is connected to the expansion connector 13 in the mobile personal computer 10 of the present embodiment. Show.

  FIG. 8 shows the experimental results of confirming the degree of the electrochemical corrosion of the terminal pins 14 caused by the attached moisture on the extension connector 13 of the mobile personal computer 10.

  In the experiment, when the expansion connector 13 is left in water overnight (about 15 hours) in a state where a voltage is applied to the terminal pin of the expansion connector 13 at a predetermined duty ratio, the terminals at the portions where the respective voltages are applied The state of the pin 14 is shown.

  FIG. 8A shows the entire expansion connector 13. FIG. 8B is an enlarged view of the terminal pin 14 of the expansion connector 13 at the upper right portion in the drawing shown as 51 in FIG. 8A. Since the voltage is continuously applied to the terminal pin 14 in the portion shown in FIG. 8B, the duty ratio of the on time is 1.

  FIG. 8C is an enlarged view of the terminal pin 14 of the expansion connector 13 in the lower right part of the drawing shown as 52 in FIG. A voltage having a pulse width of 2 μs and a period of 20 ms was applied to the terminal pin 14 shown in FIG. 8C as in the detection terminal pin 34 of the present embodiment. The duty ratio of the on-time of the voltage applied to the portion shown in FIG. 8C is 1/10000.

    FIG. 8D is an enlarged view of the terminal pin 14 of the extension connector 13 in the lower left part of the drawing shown as 53 in FIG. A voltage is not applied to the terminal pin 14 in the portion shown in FIG. 8D, and the on-time duty ratio corresponds to zero.

  8 (a), FIG. 8 (b), FIG. 8 (c), and FIG. 8 (d), as is clear from the comparison between FIG. 8 (a) and FIG. In the portion 51), the electrochemical corrosion of the terminal pin 14 proceeds due to the current flowing between the terminal pins 14, and the terminal pin 14 turns green due to the generation of patina. Therefore, in FIG. 8B, which is an enlarged view, the terminal pin 14 is confirmed as compared with FIG. 8D, which is an enlarged view of the portion 53 in FIG. 8A where no voltage is applied. It's getting harder.

  On the other hand, like the detection terminal pin 34 of the present embodiment, the portion 52 in FIG. 8A showing a state in which a voltage with a duty ratio of on-time of 1/10000 is applied is almost electrochemical. There is no corrosion. In FIG. 8C, which is an enlarged view, the terminal pin 14 should be clearly confirmed as in FIG. 8D, which is an enlarged view of the portion 53 in FIG. 8A where no voltage is applied. Can do.

  As described above, according to the detection mechanism 32 of the mobile personal computer 10 of the present embodiment, the voltage for detecting whether or not the connection terminal is connected is used as a gap pulse voltage to reduce the duty ratio of the on-time. Thus, it is possible to detect whether or not the connection terminal is connected while effectively preventing electrochemical corrosion when a conductive substance such as moisture adheres to the terminal pin 14.

  As shown in FIGS. 6 and 7, in the mobile personal computer 10 of the present embodiment, the duty of the intermittent pulse voltage applied to the detection terminal pin 34 by the output unit 36 of the detection mechanism 32 of the control unit 31. The ratio was 1 / 10,000. However, the duty ratio of the pulse voltage is not limited to 1 / 10,000. As shown in FIG. 8, the terminal pin 14 is in a state where the electrochemical corrosion of the terminal pin 14 progresses to produce patina. If there is no. Specifically, when the duty ratio of the on-time is a value smaller than about 1/1000, it is possible to sufficiently obtain the effect of reducing the average current amount and preventing electrochemical corrosion.

  Further, in the output unit 36 in the present embodiment, the case where the on-time of the pulse voltage applied to the detection terminal pin 34 is 2 μs is exemplified, but this has the effect of reducing the average current amount and preventing electrochemical corrosion. This is because the reference clock frequency of the microcomputer on which the output unit 36 is mounted is 2 μs, and it is easy to use this as it is in circuit design.

  For this reason, there is no problem that the on-time 41 is larger than 2 μm, for example, about 6 to 10 μs, for example, in designing the circuit constituting the output unit 36. Similarly to the on-time 41, the standby time 46 after the pulse voltage is applied, and further, after the voltage value of the detection terminal pin 34 is measured by the measurement unit 37, until the voltage is reset to the Lo level. The time 47 is not limited to 1 μs and 1 to 2 μs, respectively, as illustrated, but can be appropriately changed within a range in which there is no problem in detecting the connection of the connection terminal according to the purpose.

  Further, the duty ratio of the on-time of the pulse voltage is closer to a non-conductive state as the value is smaller, and the effect of preventing the electrochemical corrosion of the detection terminal pin 34 is increased. If there is no burden, it is preferable to reduce the duty ratio of the on-time. For this reason, if there is no burden in circuit design, applying an intermittent pulsed voltage whose duty ratio of on-time is smaller than 1/10000 can reduce the electrochemical corrosion of the detection terminal pin 34. Needless to say, a higher effect can be obtained.

  In addition, in the detection mechanism 32 of this embodiment shown in FIG. 4 and FIG. 5, the structure which the measurement part 37 measures the voltage of the detection terminal pin 34 to which the output part 36 applies a pulse voltage was illustrated. In this way, the terminal pin 14 necessary for detecting the connection of the connection terminal is only one of the detection terminal pins 34, and the limited terminal pins 14 and 24 between the expansion connector 13 and the connection connector 23 are provided. This is because the number can be used effectively without wasting it.

  However, this configuration is only an example, and when it is difficult to switch the output unit 36 and the measurement unit 37 to the same detection terminal pin 34 as the detection mechanism 32, the detection that the output unit 36 applies a pulse voltage is detected. The terminal pin 14 may be different from the terminal pin for measurement for measuring this voltage. In this case, for example, the device side detection terminal pin 35 connected to the detection terminal pin 34 to which the output unit 36 applies the pulse voltage, and the terminal pin of the expansion connector 13 for the measurement unit 37 to measure the voltage value The terminal pin 24 on the side of the connection connector 23 connected to 14 is connected in the cradle 20.

  Further, in the detection mechanism 32 shown in FIG. 5, the configuration in which the detection terminal pin 34 connected to the output unit 36 is clamped by the capacitor C via the resistor R is shown. However, the circuit configuration of the detection mechanism 32 is not limited to this, and the configuration is not limited as long as the connection state of the detection terminal pin 34 can be detected by applying a pulse voltage. For example, a capacitor C is inserted in series between the resistor R and the detection terminal pin 34, and the AC component of the pulse voltage output from the output unit 36 is grounded on the cradle 20 side to the device side detection terminal pin 35. It can be set as the structure which measures the change by being. In this case, compared with the configuration of the present embodiment shown in FIG. 5, the circuit for generating the voltage to be applied and the circuit configuration for detecting this are complicated, but a direct current flows through the detection terminal pin 34. Therefore, the electrochemical corrosion of the detection terminal pin 34 can be more effectively prevented.

  The electronic device according to the present invention has been described by exemplifying the case where a mobile personal computer is used as a portable information device and a cradle is used as an expansion device. However, the electronic device of the present invention is not limited to these, and as a portable information device, various terminals including a terminal side connection terminal for connecting to an external device having a secondary battery as a power source inside, Specifically, it is used indoors, such as mobile phones, portable game machines, PDAs, memory audio devices, mobile devices such as portable navigation devices and portable televisions, and handsets of telephones and intercoms. It can be applied to all portable devices.

  In this case, the external device to which the terminal side connection terminal is connected is not limited to the cradle described in the present embodiment, and can be connected to various electronic devices that are connected via a connector.

  Further, the extension device is not limited to the cradle having various functions exemplified as the present embodiment, and a desktop holder having only a function for charging the secondary battery of the portable information device can be used. Furthermore, the present invention can be applied to various external devices that include a device-side connection terminal connected to the terminal-side connection terminal of the portable information device and are used as a medium for connection with other electronic devices.

  The portable information terminal, electronic device, and connection detection mechanism of the present invention can be used for various applications, mainly for mobile use and portable use.

10 Mobile PC (personal digital assistant)
13 Expansion connector (terminal side connection terminal)
14 Terminal pin 15 Body circuit (internal circuit)
17 Switch element 18 Secondary battery 20 Cradle (expansion equipment)
23 Device side connection terminal 31 Control unit 32 Detection mechanism (connection detection mechanism)
34 Detection terminal pin

Claims (9)

A terminal-side connection terminal;
An internal circuit including a secondary battery as an operating power supply;
A switch element provided between the terminal-side connection terminal and the internal circuit;
A control unit,
The control unit applies an intermittent pulse voltage to the detection terminal pin of the terminal side connection terminal, and measures the change in potential of the pulse voltage, thereby connecting the terminal side connection terminal to an external device connection terminal. When the connection terminal of the external device is connected to the terminal side connection terminal, the switch element is operated to connect the terminal side connection terminal and the internal circuit. A portable information device characterized by:   2. The portable information device according to claim 1, wherein the pulse voltage has a duty ratio of on time of 1/1000 or less.   3. The portable information device according to claim 2, wherein the pulse voltage has a duty ratio of on time of 1 / 10,000 or less.   The portable information device according to claim 1, wherein the control unit measures a change in potential of the pulse voltage using the detection terminal pin to which the pulse voltage is applied. A portable information device including a terminal side connection terminal, an internal circuit including a secondary battery as an operation power supply, a switch element provided between the terminal side connection terminal and the internal circuit, and a control unit;
When the portable information device is mounted, the portable information device includes a device-side connection terminal connected to the terminal-side connection terminal of the portable information device, and charges at least the secondary battery of the portable information device via the device-side connection terminal And an expansion device that supplies charging current to
The control unit of the portable information device applies an intermittent pulse voltage to the detection terminal pin of the terminal-side connection terminal, and measures a change in potential of the pulse-like voltage, so that the terminal-side connection terminal It is detected whether the device side connection terminal of the extension device is connected, and when the device side connection terminal is connected to the terminal side connection terminal, the terminal side connection terminal is operated by operating the switch element. And an internal circuit.   The device-side detection terminal pin of the device-side connection terminal of the expansion device connected to the detection terminal pin of the terminal-side connection terminal is grounded, and the control unit of the portable information device outputs the pulse voltage. The electronic device according to claim 5, wherein a change in potential of the pulse voltage is measured using the applied detection terminal pin. An output unit for outputting an intermittent pulse voltage applied to the detection terminal pin of the terminal side connection terminal;
A measurement unit that measures the potential of the detection terminal pin after a predetermined time has elapsed after the output unit applied the pulse voltage;
A connection detection mechanism comprising: a detection unit configured to detect whether the terminal-side connection terminal is connected to a connection terminal of another device based on the potential measured by the measurement unit.   The connection detection mechanism according to claim 7, wherein the output unit forcibly applies a Lo level potential to the detection terminal pin after the measurement unit measures the potential of the detection terminal pin.   The detection unit determines that the terminal-side connection terminal is connected to the connection terminal of the external device when the potential of the measurement terminal pin measured by the measurement unit is continuously at the Lo level three times. The connection detection mechanism according to claim 7 or 8.