JP4718819B2 - Portable information terminal and self-diagnosis method of portable information terminal - Google Patents

Description

  The present invention relates to a portable information terminal equipped with a fuel cell and a self-diagnosis method for the portable information terminal. For example, the portable information terminal is used as an information providing means for providing visitors with information on exhibits in public facilities such as an exhibition hall. The present invention relates to an information terminal and a self-diagnosis method for the portable information terminal.

In recent years, portable electronic devices such as mobile phones, notebook computers, audio / visual devices, camcorders, PDAs (Personal Digital Assistants), etc., are rapidly spreading due to advances in electronic technology. In such portable electronic devices, a system driven by a secondary battery is the mainstream, and in order to extend the driving time, Ni / Cd battery, Ni / hydrogen battery, and lithium ion ( New types of secondary batteries with high energy density, such as (Li-ion) secondary batteries, have come to be installed. As a result, the portable electronic device is further reduced in size and weight, and further enhancement of the functionality of the portable electronic device is achieved. In particular, in order to further increase the energy density for Li-ion secondary batteries, the development of battery active materials and the development of high-capacity battery structures have been promoted, in order to realize a battery power source with a longer usage time per charge. Efforts are being made. As a result, the capacity is improved several times in volume ratio as compared with the conventional secondary battery.
However, secondary batteries must be charged after using a certain amount of power, and charging equipment and a relatively long charging time are required, so that portable electronic devices can be used at any time and anywhere. In order to drive continuously over time, it is necessary to use a portable electronic device while charging.

In addition, portable information terminal devices (hereinafter referred to as portable information terminals) for lending to visitors in public facilities such as museums and museums and explaining exhibits are known as portable electronic devices (for example, portable information terminals) (for example, , See Patent Document 1). According to this technology, communication is performed between a portable information terminal held by a visitor and an exhibit, and information such as characters, images, or sounds related to the description of the exhibit is displayed or reproduced on the portable information terminal. be able to. In the portable information terminal used for such a use, it is necessary to use the portable information terminal while ensuring a sufficient battery capacity of the secondary battery. Therefore, a technology for securing the battery capacity of the secondary battery by simultaneously mounting the fuel cell in addition to the secondary battery in the portable information terminal and operating the secondary battery with the fuel cell is disclosed ( For example, see Patent Document 2).
As the fuel cell, a fuel cell in which liquid fuel is oxidized at the anode of a membrane / electrode assembly (MEA) composed of an anode, an electrolyte membrane, a cathode, and a diffusion layer, and oxygen is reduced at the cathode. In the technology disclosed in Patent Document 2, a direct methanol fuel cell (DMFC) is used as a representative fuel cell.

When the fuel cell is used in this way, in order to prevent deterioration of the characteristics of the fuel cell, the secondary battery is appropriately charged while performing self-diagnosis of the charging circuit including the fuel cell. For example, the resistance value of the membrane resistance is obtained based on the voltage generated in the membrane resistance of the fuel cell, and the resistance value of the reaction resistance is obtained based on the current value flowing through the reaction resistance and the voltage value generated in the reaction resistance. A technique is disclosed in which an effective resistance of a fuel cell is efficiently obtained in a short time from the obtained membrane resistance and reaction resistance values, and self-diagnosis is performed to determine whether or not the characteristics of the fuel cell have deteriorated (for example, And Patent Document 3).
Japanese Patent Laying-Open No. 2002-259612 (see paragraph numbers 0011 to 0029 and FIGS. 1 to 9) Japanese Patent Laying-Open No. 2004-227832 (see paragraph numbers 0014 to 0043 and FIGS. 1 to 7) JP 2003-223918 A (refer to claim 1 and FIG. 1)

  However, as long as it is a portable information terminal even if it is used for different purposes, it is necessary to always use it while securing the battery capacity of the secondary battery, but depending on the environment of the facility used, the usage time of the portable information terminal becomes longer. Sometimes. For example, in the environmental conditions of a facility with a large number of visitors in large-scale expositions and exhibitions, if the number of portable information terminals to lend is not enough, the time to charge the portable information terminals will be insufficient, A lot of personal digital assistants must be prepared to cover it. In addition, it is a heavy burden on the staff to provide a portable information terminal having a sufficient battery capacity to visitors while regularly performing operations such as renting, collecting, and charging while the exhibition is open. Furthermore, it is a heavy burden on the staff to accurately and quickly grasp the state of charge of the portable information terminal so that the portable information terminal with insufficient battery capacity is not lent to visitors.

In order to solve these problems, it is conceivable to install a large number of secondary batteries to secure the battery capacity. However, in this case, the handy type advantage in the portable information terminal is impaired, and this is not an appropriate method. .
Further, even if a portable information terminal equipped with a secondary battery and a fuel cell (DMFC) as disclosed in Patent Document 2 is used, the portable information terminal is turned off by DMFC when the portable information terminal is turned off (that is, when it is returned). Because the secondary battery is charged, sufficient charging time cannot be secured when the rental and recovery cycle is fast or when the battery is lent for a long time and the remaining battery capacity is low. There is a possibility that the portable information terminal cannot be delivered to the next visitor in a fully charged state.

  Further, when the fuel cell is used for a long time, the output characteristics may be deteriorated due to bubbles or water droplets, or the start-up characteristics may be deteriorated when the fuel cell is used in the next cycle. In such a state, there is a possibility that the fuel cell cannot be properly charged from the secondary battery. Further, in the fuel cell self-diagnosis method according to the technique of the above-mentioned Patent Document 3, it is impossible to accurately self-diagnose the deterioration of the output characteristics and start-up characteristics of the fuel cell caused by bubbles and water droplets. May not be detected at an early stage, and as a result, the secondary battery may not be properly charged from the fuel cell.

  The present invention has been made in view of the problems as described above, and is a state that is not recognized by the user when a relatively small-capacity secondary battery and a fuel cell are mounted for effective charging and discharging. It is an object of the present invention to provide an easy-to-use portable information terminal capable of performing self-diagnosis and power generation retry of a fuel cell, and a self-diagnosis method for the portable information terminal.

In order to achieve the above object, a portable information terminal of the present invention is a portable information terminal that provides desired information, and a plurality of sets of secondary batteries that are charged and discharged independently , and a secondary battery A fuel cell for charging the battery and display means for displaying information in the operating state and not displaying information in the standby state in which the operation of the portable information terminal is stopped, and by an operation of transitioning from the operating state to the standby state Perform self-diagnosis, if there is no abnormality, transition to the standby state as it is, if there is an abnormality, display the content of the abnormality on the display means, to grasp the state of the fuel cell during charging by the fuel cell, When the fuel cell is in an abnormal state, the abnormality information of the fuel cell is stored in the storage means, and the next self that is performed based on the operation of changing the state of the portable information terminal The abnormality information when the cross-sectional, characterized in that to be displayed on the display means.

Further, in the portable information terminal according to the present invention, self-diagnosis is performed by an operation for changing from the standby state to the operating state, and if there is no abnormality, the operation state is shifted as it is and the initial screen is displayed on the display means. In some cases, the abnormality content is displayed on the display means.

Further, in order to achieve the above object, the portable information terminal of the present invention is a portable information terminal that provides desired information, and a plurality of sets of secondary batteries that are charged and discharged independently, and two a fuel cell to charge the next battery, a charging means for charging individual sets of rechargeable batteries from a fuel cell, and a step-up DC / DC converter that Mashimasu through between the fuel cell and the charging means The step-up DC / DC converter has a shutdown function to stop the operation of the step-up DC / DC converter when an abnormal voltage occurs in the fuel cell, and the first charging current command value and the first During charging by the fuel cell based on a second charging current command value equal to or less than 1/2 of the charging current command value of 1 and a logic signal corresponding to normality / abnormality of the output voltage of the step-up DC / DC converter , First charging current When the secondary battery is charged with the command value and the logic signal becomes a signal indicating abnormality of the step-up DC / DC converter, the charge current command value is changed to the second charge current command value for a predetermined time. The secondary battery is charged, and after a predetermined time has elapsed, the charging current command value is changed to the first charging current command value again to charge the secondary battery .

  Furthermore, in the portable information terminal of the present invention, the power capacity of the fuel cell is less than the average power consumption in the operating state in which the portable information terminal is operated.

The present invention also provides a plurality of sets of secondary batteries, fuel cells, charging means for charging the secondary batteries from the fuel cells, and boosting interposed between the fuel cells and the charging means. a DC / DC converter, a self-diagnosis method for a portable information terminal having a step-up DC / DC converter having a function of stopping the abnormal voltage occurs during the step-up DC / DC converter operation in the fuel cell, the charging means A first charging current command value to be transmitted, a second charging current command value smaller than the first charging current command value, and a logic signal corresponding to normality / abnormality of the output voltage of the step-up DC / DC converter are used. , during charging by the fuel cell, the procedure by the first charging current command value to charge the secondary battery, when the logic signal is a signal indicating an abnormality of the boost DC / DC converter, charge The flow command value is changed to the second charge current command value, the procedure for charging the secondary battery over a predetermined time, and after the predetermined time has elapsed, the charge current command value is changed to the first charge again. And changing the current command value to charge the secondary battery.

  Further, in the portable information terminal self-diagnosis method of the present invention, the second charging current command value is 1/2 or less of the first charging current command value.

Further, in the self-diagnosis method of the portable information terminal of the present invention, when the change operation of the charging current command value has exceeded a predetermined number of times, the abnormality information of the fuel cell is stored in the storage means and the operation of the portable information terminal is performed. The abnormality information is displayed at the time of the next self-diagnosis performed based on an operation of changing the state between the state and the standby state in which the operation of the portable information terminal is stopped .

  Further, in the self-diagnosis method of the portable information terminal of the present invention, when the charging current command value is the second charging current command value and the logic signal corresponds to the abnormality of the step-up DC / DC converter, The step-up DC / DC converter is stopped, and after a predetermined time has elapsed, the step-up DC / DC converter is operated again and the secondary battery is charged with the second charge current command value.

Further, in the portable information terminal self-diagnosis method of the present invention, when the charging means is stopped a predetermined number of times or more, the abnormality information of the fuel cell is stored in the storage means, and the operating state of the portable information terminal and the portable information are also stored. The abnormality information is displayed at the time of the next self-diagnosis performed based on an operation of changing the state between the standby state in which the operation of the terminal is stopped .

  The portable information terminal of the present invention has been developed to achieve the above-described object. For example, a direct methanol fuel cell (hereinafter referred to as DMFC) and a plurality of sets of lithium ion secondary batteries (hereinafter referred to as Li) are provided. (Referred to as an ion battery). Regardless of whether the portable information terminal is turned on or off, one set of Li ion batteries is always charged from the fuel cell, and the other set of Li ion batteries supplies power to the load of the portable information terminal. is doing. Thus, when charging any one of the Li-ion batteries of the plurality of Li-ion batteries mounted on the portable information terminal with the DMFC, whether or not the portable information terminal is always properly charged. Need to self-diagnose. Therefore, self-diagnosis is performed when the mobile information terminal is changed from the operating state to the standby state, or when the mobile information terminal is changed from the standby state to the operating state. In some cases, the abnormal content is displayed. At this time, when transitioning between the operating state and the standby state, the magnitude of the charging current command value is changed, or the output voltage of the step-up DC / DC converter interposed between the fuel cell and the charging means is normal / By using the logic signal corresponding to the abnormality to cause the fuel cell to perform power generation retry in a different charging mode, it is possible to optimally charge the Li ion battery while performing an appropriate self-diagnosis.

According to the present invention, regardless of whether the portable information terminal is in a standby state or in an operating state, there is always a set of secondary batteries among a plurality of sets of secondary batteries (for example, Li ion batteries). It is charged by a fuel cell (eg, DMFC). Therefore, since the secondary battery need not be charged by a commercial power source during daytime operation in the exhibition hall, the burden on the rental / return of the portable information terminal by the staff is reduced.
In addition, when the mobile information terminal is changed from the operating state to the standby state, or when the portable information terminal is changed from the standby state to the operating state, the self-diagnosis is automatically performed. When there is an abnormality, the abnormality content is displayed, so that the secondary battery can always be properly charged and an early response in the event of a failure can be performed. As a result, it is possible to provide a portable information terminal that is easy to use for both the staff of the exhibition hall and the visitors.

  Hereinafter, several embodiments for explaining exhibits at an exposition will be described with reference to the drawings, with regard to a fuel cell mounted portable information terminal and a self-diagnosis method for a portable information terminal according to the present invention. In the drawings used below, the same components are denoted by the same reference numerals, and redundant description is omitted as much as possible.

<Outline of the invention>
In the present invention, a direct methanol fuel cell (hereinafter abbreviated as DMFC) as a fuel cell and a Li ion secondary battery (hereinafter abbreviated as Li ion battery) as a secondary battery are mounted on the portable information terminal. The Li-ion battery is always operated while being charged from the DMFC regardless of the on / off state of the portable information terminal. In this portable information terminal, explanations of handling methods for visitors are stored, and immediately before handing over the portable information terminal to lend it to a visitor, an attendant presses a button on the portable information terminal to turn on the power. Thereby, the power source of the portable information terminal is turned on, and a screen explaining the handling method for the visitors is displayed. In addition, the portable information terminal is provided with a reading device (reader) for reading information recorded on an RFID (Radio Frequency Identification) chip and an antenna so that visitors can visit the exhibits in the exhibition hall. Is brought close, information transmission is performed between the RFID chip incorporated in the exhibit and the portable information terminal. As a result, images related to exhibits corresponding to information transmitted from the RFID chip from a memory, a large-capacity hard disk device, or a removable hard disk (so-called iVDR: Information Versatile Disk for Removable usage) incorporated in the portable information terminal. Play data, text, and audio. Hereinafter, such a mode of the portable information terminal is referred to as an operating state.

  Further, when the portable information terminal is returned from the visitor, after the attendant receives the portable information terminal, the portable information terminal reads the predetermined information from the specific RFID chip so that the portable information terminal Enter diagnostic mode. After checking the state of the DMFC and the charging state of the Li-ion battery, if the charging state is normal, the portable information terminal is automatically turned off, and the charging mode only charges the Li-ion battery from the DMFC. to go into. Mobile information terminals that have entered the charging mode are rented to visitors again in order while being managed in the backyard. Further, when the building is closed at night or the like, the Li ion battery is directly charged by an AC charger (commercial power) installed in the backyard, and the Li ion battery is fully charged before the next opening. When charging with an AC charger, charging by the DMFC is stopped. Hereinafter, such a mode of the portable information terminal is referred to as a standby state. Thus, by switching the charging mode between the operating state and the standby state of the portable information terminal, the Li-ion battery is charged by the DMFC during the opening and the Li-ion battery is charged by the AC charger after the closing. Even if the capacity of the Li-ion battery is reduced, it is possible to operate the portable information terminal while ensuring a sufficient battery capacity for the Li-ion battery without charging from the AC charger during the opening.

  In addition, two Li-ion batteries that can be charged and discharged independently are prepared. A Li-ion battery that is charged from the DMFC in the operating state (hereinafter referred to as a charging-side Li-ion battery) and a Li that supplies power to the load in the operating state. The role is shared with the ion battery cell (hereinafter referred to as a power supply side Li ion battery). And when the information from a specific RFID chip is read at the time of return from a visitor, the role of each Li ion battery cell is switched. In other words, the charging-side Li ion battery in the previous operating state is the feeding-side Li ion battery in the next operating state, and the feeding-side Li ion battery in the previous operating state is the charging-side Li ion battery. Also, the capacity of the two Li-ion batteries is monitored by the remaining battery management function (hereinafter referred to as SOC), and the DMFC charging system is switched so that the Li-ion battery with the smaller remaining capacity is charged from the DMFC. It is carried out. Furthermore, since the fuel cell start-up time may vary, the fuel cell start-up can be performed by monitoring the PG signal of the DC / DC converter and changing the charging current command value of the Li-ion battery. Cover the defects in

  Furthermore, when the portable information terminal is changed from the operating state to the standby state, or when the portable information terminal is changed from the standby state to the operating state, the self-diagnosis is automatically performed. Such a self-diagnosis is performed when, for example, a Li-ion battery is charged from a DMFC with a normal charging current and the output voltage of the step-up DC / DC converter decreases (that is, when the PG signal becomes L). Aging is performed by lowering the charging current. And after performing aging for 60 second, it returns to normal charging current, and such operation is repeated up to 30 times. When the output voltage of the step-up DC / DC converter decreases during aging (that is, when the PG signal becomes L), aging is stopped, aging is performed again after 20 seconds, and such an operation is performed 10 times. Repeat until. If the power generation retry is abnormal, the DMFC abnormality is displayed.

<First Embodiment>
Next, a first embodiment of a portable information terminal according to the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram showing a method of operating a fuel cell-mounted portable information terminal according to the present invention.
First, the flow of operation of the portable information terminal 50 equipped with a fuel cell according to the present invention will be schematically described with reference to FIG. When a visitor enters from the entrance 59 of the exhibition hall 61, the clerk lends to the visitor at the rental window 55. At this time, immediately before the portable information terminal 50 is handed over, the attendant presses the button of the portable information terminal 50 twice to turn on the power. Thus, when the portable information terminal 50 is turned on, an initial explanation screen for explaining the handling method for the visitors is displayed. Visitors can understand the operation method of the portable information terminal 50 from the information shown on the explanation screen. Next, when the visitor moves the portable information terminal 50 closer to the exhibit 52a in the exhibition hall by the operation method shown on the explanation screen, for example, the RFID chip 51a incorporated in the exhibit 52a and the RFID reader of the portable information terminal 50 69 (see FIG. 6). As a result, information related to the exhibit 52a is reproduced from the iVDR 47, the memory 63 (see FIG. 6), and the like configured by a large-capacity hard disk incorporated in the portable information terminal 50 by voice, characters, images, or the like. In the same way as for the exhibit 52b, information related to the exhibit 52b is reproduced according to the information from the RFID chip 51b incorporated in the exhibit 52b. At this time, one Li ion battery is the power supply side, and the other Li ion battery is the charging side charged by the DMFC.

  In this way, the visitor makes a round of the hall while reproducing the information in the desired exhibit using the portable information terminal 50, and then returns the portable information terminal 50 at the return window 56 near the exit 60. Then, after the clerk receives the portable information terminal 50, the portable information terminal 50 is brought close to the specific RFID chip 53, and information for self-diagnosis is read. Thereby, the portable information terminal 50 enters the self-diagnosis mode. In the self-diagnosis mode, the state of the DMFC and the charge state of the Li ion battery are checked. Then, after automatically checking the state of the DMFC and the charging state of the Li-ion battery, if the charging state is normal, the portable information terminal 50 is automatically turned off, and the charging mode only charges the Li-ion battery from the DMFC. to go into. At this time, the charging system is switched so that the power supply side Li ion battery in the previous operation state becomes a charge side Li ion battery charged from the DMFC, and the charge side Li ion battery in the previous operation state becomes the power supply side Li ion battery. Is done.

  When the portable information terminal 50 switches the charging system by reading information from a specific RFID chip 53 at the time of return, the charging system of the DMFC is always switched to the Li-ion battery having the smaller remaining capacity by the SOC determination. There is no risk of switching the DMFC charging system to the charged Li-ion battery.

  The returned portable information terminal 50 is transported to the rental counter 55 by the cart 54 while being charged by the DMFC, and is again lent to the visitors. When the building is closed at night or the like, the power supply side Li-ion battery and the charging side Li-ion battery are directly charged by the AC charger (charging rack) 58 installed in the backyard. At this time, charging by the DMFC is stopped. Thus, all Li-ion batteries are fully charged before the next opening.

FIG. 2 is a diagram showing the appearance of the portable information terminal, and FIG. 3 is a cross-sectional view taken along the line AA of the portable information terminal shown in FIG.
As shown in FIG. 2, the portable information terminal 50 has an iVDR outlet 41 and an air hole 42 on the front side of the portable information terminal 50, and buttons 43 and 44 that can be operated by an attendant or a visitor on the operation surface. Is arranged. A liquid crystal screen 45 that can be changed to an easy-to-see tilt angle is disposed at the rear part on the front side. Further, a cartridge exchange port 48 for exchanging the fuel cartridge of the fuel cell is provided on the left side of the main body, and a fuel confirmation window 40 is provided on the upper surface thereof. As shown in the cross-sectional view of FIG. 3, an iVDR 47 including a fuel cell unit 11, a Li ion battery 18a, a Li ion battery 18b, a hard disk, and the like is accommodated in the portable information terminal 50. Further, an RFID antenna 46 is disposed on the back of the case of the liquid crystal screen 45. The DMFC is stored in the fuel cell unit 11. The portable information terminal 50 includes a power supply circuit system as shown in FIGS. 4 and 5 and performs charge / discharge control for the Li ion battery 18a or the Li ion battery 18b. Details of the power supply circuit system will be described later.

As shown in FIG. 6, the portable information terminal 50 includes an RFID reader 69, a bus controller 70, a CPU 62, a memory 63, an iVDRI / F 65, a connector 64, an LCD controller 68, a backlight controller 66, and a backlight 67 as control units. It has been.
An RFID reader 69, CPU 62, memory 63, iVDRI / F 65, LCD controller 68, and backlight controller 66 are connected to the bus controller 70. The memory 63 is further connected to the CPU 62.
The aforementioned iVDR 47 is composed of a large-capacity hard disk or the like and is detachably connected to the bus controller 70 via the iVDRI / F65.
The RFID antenna 46 described above is connected to an RFID reader 69.
The liquid crystal screen 45 is connected to an LCD controller 68 and illuminated by a backlight 67 connected to a backlight controller 66.
This control unit becomes a load of the power supply in the portable information terminal 50.

  Next, the operation flow of the portable information terminal 50 in the present invention will be described in detail. It is necessary to prepare a large number of portable information terminals 50 in one exhibition hall 61 (see FIG. 1). The number of visitors is the number of visitors per hour, average residence time, retention rate for all visitors, and visitors. In addition to the number calculated by the ratio of the time used to the time not used, the power consumption of the portable information terminal 50, the amount of power generated by the fuel cell unit 11, etc., the number added with a spare device at the time of failure is required For example, a large-scale exposition where more than one hundred visitors can enter simultaneously will be several hundred.

FIG. 9 is a flowchart showing a flow at the time of lending the portable information terminal to a visitor at the lending window in the operation method of the portable information terminal.
In FIG. 1, when a visitor enters from the entrance 59 of the exhibition hall 61, the attendant lends the portable information terminal 50 to the visitor at the rental window 55. When the battery capacity of the Li-ion battery 18a or the Li-ion battery 18b decreases due to use of the portable information terminal 50 lent to a visitor, the fuel cell unit 11 mounted therein operates as shown in FIG. Any one of the Li-ion battery 18a and the Li-ion battery 18b whose battery capacity has been reduced (that is, the charging-side Li-ion battery) is charged. Therefore, when the button 44 (see FIG. 2) of the portable information terminal 50 that the attendant lends is pressed twice, for example (step S1), the portable information terminal 50 is turned on.

At this time, when the Li-ion battery 18a or the Li-ion battery 18b is charged by the fuel cell unit 11, the power is turned on in the DMFC charged state (step S2), and the portable information terminal 50 immediately enters the self-diagnosis mode to determine abnormality. Perform (step S3). As a result, if it is determined that the portable information terminal 50 is abnormal, the process proceeds to a failure sequence (step S4), and the abnormality content is displayed on the liquid crystal screen 45 (see FIG. 2) of the portable information terminal 50 (step S5). The failure content to be determined includes, for example, a charging failure of the Li ion battery 18a and the Li ion battery 18b, a power generation state abnormality of the fuel cell unit 11, and the like. Further, the content of the abnormality is written and stored in the memory 63 shown in FIG.

  If the portable information terminal 50 diagnoses that there is no abnormality as a result of the self-diagnosis in step S3, an initial operation explanation screen is automatically displayed on the liquid crystal screen 45 (see FIG. 2) of the portable information terminal 50 (step S6). . As a result, the portable information terminal 50 enters an operation state mode that is an operation state (step S7). At this time, the backlight 67 that illuminates the liquid crystal screen 45 for the first time is turned on by the backlight controller 66 (see FIG. 6). Therefore, the attendant can confirm whether or not the portable information terminal 50 is in a normal state by turning on the backlight 67 by displaying the operation screen on the liquid crystal screen 45 (see FIG. 2) before giving it to the visitors (see FIG. 2). Step S8).

  Although the operation explanation screen is not particularly shown in the flowchart of FIG. 9, the following functions can be realized as options. That is, the clerk determines whether the visitor is an adult, a child, or a foreigner, and changes the way of pressing the button 44 in FIG. 2 to display an optimal initial screen for the visitor. Can be displayed. For example, if you are an adult, pressing the button 44 twice will display kanji-kana characters, if you are a child, pressing the button 43 twice will display only hiragana characters, It is possible to select an optimum display for the visitors by distinguishing the display characters, such as displaying English sentences when the button 44 is pressed once. At this time, such a determination can be stored in the memory 63 or iVDR 47 of FIG. 6 as visitor information. Of course, the push button may be provided with a dedicated button, or the same effect can be obtained by variously changing how the same button is pushed. Even if the display of the initial screen is changed in this way, the result of the self-diagnosis is displayed in the same way.

  Returning to the flowchart of FIG. 9 again, the clerk confirms the state of the portable information terminal 50 by displaying the operation screen in step S8. If the portable information terminal 50 is displayed as being abnormal, the portable information terminal 50 is classified as a malfunctioning machine and is not lent out (step S9). On the other hand, if the message indicating that there is no abnormality is displayed on the portable information terminal 50, the attendant checks the remaining amount of fuel in the fuel cartridge from the fuel confirmation window 40 of the portable information terminal 50 shown in FIG. 2 (step S10). When the fuel remaining amount is a predetermined amount, the portable information terminal 50 is lent out to the visitors (step S12). On the other hand, if the remaining amount of fuel is less than the predetermined amount, the cartridge exchange port 48 (FIG. 2) is opened and the fuel cartridge inside is taken out and replaced (step S11). 50 is lent out (step S12). It is desirable that the cartridge exchange port 48 shown in FIG. 2 has a structure that can be opened and closed only by using a special tool so that visitors cannot open it carelessly.

  Accordingly, when the visitor receives the portable information terminal 50 on which the operation screen is displayed, as shown in FIG. 1, the attendant understands the operation method according to the display of the initial explanation, moves to the vicinity of the exhibit 52a, and exhibits. Appreciate things. Since the RFID chip 51a is attached to the stand of the exhibit 52a, the visitor brings the portable information terminal 50 close to the position of the RFID chip 51a or 51b according to the display of the exhibit 52a. At this time, as shown in FIG. 3, since the RFID antenna 46 of the portable information terminal 50 is arranged on the back surface of the liquid crystal screen 45, the visitor brings the RFID antenna 46 close to the RFID chip 51a or 51b with a reasonable posture. be able to. In the case where the exhibit 52a or 52b is a large panel or the like, not a display 52a itself, but a structure in which a visitor can easily approach the portable information terminal 50, for example, a columnar access point is provided in the vicinity thereof. An RFID chip 51a or 51b may be attached.

  Next, as shown in FIG. 1, when the portable information terminal 50 receives a signal from the RFID chip 51a or 51b via the RFID antenna 46 (FIG. 3), the RFID reader 69 (see FIG. 6) receives the signal from the RFID antenna 46. The information is read from the RFID chip 51a or 51b (FIG. 1). Then, the CPU 62 (see FIG. 6) accesses a predetermined address of the iVDR 47 via the iVDR interface 65 according to this information, and expands the information stored in the iVDR 47 in the memory 63. The information developed in the memory 63 is sequentially displayed on the liquid crystal screen 45 of FIG.

As a result, in FIG. 1, the visitor can recognize the information as if it was directly transmitted from the exhibit 52a or 52b to the liquid crystal screen 45 of FIG. 2, and can read characters and images related to the exhibit 52a or 52b. . In this way, the visitors proceed according to the route with the exhibits 52a, 52b, etc., and perform similar access to the interesting exhibits. At this time, in the iVDR 47 (see FIG. 6) of the portable information terminal 50, which exhibit the visitor has accessed can be written together with the current time. The information written in the iVDR 47 can be analyzed later and used as visitor statistics. In addition, the iVDR 47 can be taken out from the iVDR take-out port 41 of FIG. 2 and entered and taken out by other information devices such as a personal computer. That is, as shown in FIG. 6, the iVDR 47 can be separated from the connector 64 and freely taken out. Examples of such applications include taking out iVDR 47 and bringing it into an external server or in-vehicle device, updating exhibition data, downloading and organizing data such as visitor information and failure information, and the like. Note that when information other than characters and images is handled as information related to the exhibit 52a, processing means for handling audio signals is provided in the bus controller 70 in FIG. 6 to reproduce the audio signals read from the iVDR 47. You can also.
After going around the exhibition hall 61 in this way, the visitor returns the portable information terminal 50 to the staff at the return window 56 of FIG.

FIG. 10 is a flowchart showing a flow when the portable information terminal is returned from a visitor at the return window in the operation method of the portable information terminal shown in FIG.
When the portable information terminal 50 is returned, the clerk holds the portable information terminal 50 over a predetermined RFID chip 53 (FIG. 1) at hand (step S21). When the portable information terminal 50 reads the information from the RFID chip 53 (step S22), it immediately enters the self-diagnosis mode (step S23). If there is an abnormality in the portable information terminal 50, the process proceeds to a failure sequence (step S24), and the abnormality content is displayed on the liquid crystal screen 45 (see FIG. 2) (step S25). Note that the failure content handled here can be a power generation failure of the fuel cell unit 11 and a charging failure of the Li ion battery 18a and the Li ion battery 18b as in the case of power-on.

  On the other hand, if there is no abnormality in the self-diagnosis in step S23, the backlight 67 (see FIG. 6) is turned off by the backlight controller 66, and the screen display of the liquid crystal screen 45 in FIG. 2 is turned off (step S26). As a result, the portable information terminal 50 enters the standby mode and enters a state during DMFC charging in the standby mode (step S27). On the other hand, the clerk confirms whether or not the screen display has disappeared (step S28). If the screen display has not disappeared, the mobile information terminal 50 is classified as a faulty machine so that it is not used for the next lending ( Step S29).

  Further, if it is confirmed in step S28 that the screen display has disappeared (in the case of OFF), since the state of the portable information terminal 50 is normal, the attendant can check the fuel remaining amount of the fuel cartridge from the fuel confirmation window 40 (see FIG. 2). Is confirmed (step S30). Here, when the remaining amount of fuel in the fuel cartridge is normal, the portable information terminal 50 is placed on the cart 54 and conveyed to the rental counter 55 as shown in FIG. At this time, the Li-ion battery 18a or the Li-ion battery 18b is in a DMFC charging state in which the Li-ion battery 18a or the Li-ion battery 18b is charged with power from the fuel cell unit 11 (step S27). On the other hand, if the amount of fuel is less than the predetermined amount in the confirmation of the remaining amount of the fuel cartridge in step S30, the clerk replaces the fuel cartridge (step S31), the fuel cell unit 11 generates power with the new fuel cartridge, The Li-ion battery 18a or the Li-ion battery 18b is in a DMFC charging state in which the fuel cell unit 11 is charged (step S27).

  By holding the returned portable information terminal 50 over the RFID chip 53 and reading predetermined information from the RFID chip 53 in this way, the portable information terminal 50 is automatically powered off from the self-diagnosis. There is no risk of forgetting to turn off the power. Therefore, the power of the Li ion battery 18a and the Li ion battery 18b is not wasted, so that the portable information terminal 50 can be operated repeatedly for a long time. In addition, the visitor may read the information from the RFID chip 53 by the portable information terminal 50 at the time of return, and then hand the portable information terminal 50 to a staff member. Alternatively, a power switch may be separately provided in the portable information terminal 50 to turn off the staff member. May be. Further, when the portable information terminal 50 is not operated for a certain time or longer, the power may be automatically turned off. Of course, you may use them together.

  In FIG. 1, the portable information terminal 50 returned from the visitor and placed in a standby state is in a state of being charged with DMFC and is loaded on the cart 54 and transported to the rental counter 55. The portable information terminal 50 may be transported using a belt conveyor or a lift-type transport means instead of transporting the terminal 50, or the transport means is omitted by installing the return window 56 and the rental window 55 close to each other. May be. In any of these cases, it is desirable that the portable information terminal 50 performs order management so that the portable information terminal 50 is lent out in the order returned in the next rental.

  The DMFC charging by the fuel cell unit 11 is set as follows. That is, when the battery is used during the opening, the Li ion batteries 18a and 18b can supply sufficient electric power, and when the building is closed, the electric power remaining in the Li ion batteries 18a and 18b is reduced as much as possible, and commercial power is used for the Li ion batteries 18a and 18b. 18b is fully charged.

FIG. 7 is a diagram showing the transition of the total value of the input / output power of the Li ion battery and the remaining capacity of the Li ion battery mounted on the portable information terminal according to the present invention.
In FIG. 7, the horizontal axis indicates the passage of time, and the vertical axis indicates the input / output of the entire Li ion battery (a combination of the Li ion battery 18 a and the Li ion battery 18 b) of one portable information terminal 50 in the series of operations described above. The change of electric power and the total remaining capacity of the whole Li ion battery is shown. The balance of input / output power of the entire Li-ion battery is in the discharged state when the portable information terminal 50 is in operation, that is, in the state where the visitor is using it during opening, and the AC charging installed in the backyard during closing When the battery (charge rack) 58 is charged, it is in a charged state. Since the fuel cell unit 11 is always in a power generation state when the portable information terminal 50 is in operation, a part of the discharge power (device power consumption) of the portable information terminal 50 is borne by the fuel cell unit 11 during operation, The rest is calculated from the entire Li ion battery. Thus, as shown in FIG. 7A, by setting the discharge power of the entire Li-ion battery to exceed the output power of the DMFC, that is, the DMFC charging by the fuel cell unit 11, the portable information as shown in FIG. By repeating the operation and charging of the terminal 50, the total value of the remaining capacity of the Li ion battery 18a and the Li ion battery 18b changes in a decreasing direction as shown in the remaining capacity graph of the entire Li ion battery shown in (c).

  Here, if the opening time of the exhibition hall is 9 o'clock, the total remaining capacity of the Li ion battery 18a and the Li ion battery 18b gradually decreases from the fully charged state due to repeated operation and charging due to the change of visitors, The remaining capacity is considerably reduced at 22:00. For example, assuming that the charging power of the DMFC is 0.8 w and the load of the portable information terminal 50 is 2.5 to 3.5 w, the Li ion battery 18a can be used at 22:00 after operation due to the opening time of about 13 hours. The total remaining capacity of the Li-ion battery 18b is about 20% or less as shown in (c). When the closing time is reached after 22:00, all the portable information terminals 50 are stored in the backyard charging rack 58 shown in FIG. 1, and are charged with CCCV (constant current / constant voltage) from the AC power source (commercial power source). . At this time, the total remaining capacity of the Li-ion battery 18a and the Li-ion battery 18b increases with the charging time, and both are fully charged before opening the next day.

  Next, the operation of the charging circuit of the fuel cell unit 11, the Li ion battery 18a, and the Li ion battery 18b will be described.

FIG. 4 is a diagram showing a power supply circuit system of the portable information terminal according to the present invention.
In the present embodiment, the Li ion battery 18a and the Li ion battery 18b are Li ion batteries. However, these secondary batteries are not limited to Li ion batteries, but other secondary batteries such as nickel metal hydride batteries and nickel cadmium batteries. A battery may be used. Further, as shown in FIG. 4, a voltage monitoring circuit 19a and a voltage monitoring circuit 19b are connected to the Li ion battery 18a and the Li ion battery 18b, respectively, and further, input / output paths of the Li ion battery 18a and the Li ion battery 18b. Are connected to a current integrating circuit 20a and a current integrating circuit 20b, respectively, and output information of the current integrating circuit 20a and the current integrating circuit 20b is transmitted to the power management circuit 21.

Further, a charging control circuit 7a and a charging control circuit 7b are connected to the input sides of the Li ion battery 18a and the Li ion battery 18b, respectively, to control the charging current and the charging voltage. Furthermore, a discharge switch 8a, a discharge switch 8b, and a discharge switch 8c are connected to the output side of the AC adapter 2, the Li ion battery 18a, and the Li ion battery 18b, respectively, and the discharge switches 8a, 8b, and 8c are switched. Thus, the power supplied to the DC / DC converter 9 can be selected. As the discharge switches 8a, 8b, and 8c, it is optimal to use a power MOSFET having a relatively small on-resistance, but other means such as a relay may be used. The output of the DC / DC converter 9 is supplied to the load 10. The load 10 is composed of components as shown in FIG.
The main unit 6 is composed of the Li ion battery 18a, the Li ion battery 18b, and the circuits for controlling them. The main unit 6 includes a connector 3 for connecting the AC adapter 2 during nighttime charging and a connector 16 for connecting the fuel cell unit 11. The AC adapter 2 is stored in the charging rack 58 shown in FIG.

  Further, in addition to the DMFC 12, an OCV protection circuit 14 connected to the DMFC 12 via the connector 13 is provided inside the fuel cell unit 11. The connector 13 is used for easily connecting / disconnecting the wiring between the DMFC 12 and the OCV protection circuit 14 when the DMFC 12 is maintained or the DMFC 12 is replaced. The OCV protection circuit 14 prevents the subsequent step-up DC / DC converter 15 and the main unit 6 from being destroyed by a high voltage OCV (Open Circuit Voltage) generated when the DMFC 12 is in a power generation state with no load. Is. The step-up DC / DC converter 15 also has a role of boosting and stabilizing the output voltage of the DMFC 12. The number of series cells of the DMFC 12 in the first embodiment is 6 cells, and the output voltage of the step-up DC / DC converter is about 4.5 to 5.0V.

Next, the operation of the power supply circuit system of the portable information terminal 50 shown in FIG. 4 will be described with reference to the remaining capacity graph for each Li ion battery cell shown in FIG.
FIG. 8 shows the relationship between the state of the portable information terminal and the charge / discharge of the two sets of Li ion batteries. 7 shows the transition of the total remaining capacity of the Li ion battery 18a and the Li ion battery 18b. In FIG. 8, the transition of the remaining capacity of each of the Li ion battery 18a and the Li ion battery 18b is shown. This is because the Li-ion battery 18a and the Li-ion battery 18b are charged and discharged independently (two cells).
In FIG. 8, when the portable information terminal 50 is rented and in an operating state in the period T1, the Li ion battery 18a receives power from the DMFC 12 when the Li ion battery 18b is connected to the load 10 and is in a discharged state. DMFC charging state. Therefore, the remaining capacity of the Li ion battery 18b decreases with time, and the remaining capacity of the Li ion battery 18a increases.

  At the beginning of the period T2, when the portable information terminal 50 is returned and information is read from the specific RFID chip 53, the Li ion battery 18b is in the DMFC charged state, and the Li ion battery 18a connects the load 10. The charge / discharge system switches to the state. Here, the charge state in the backyard of the Li ion battery 18b in the period T2 will be described. In this state, the AC adapter 2 is not connected to the connector 3 (see FIG. 4), and the fuel cell unit 11 is connected to the connector 16. In this state, the state control signal 17 from the voltage monitoring circuit 4 is on because the AC adapter 2 is not connected, and the boost DC / DC converter 15 of the fuel cell unit 11 is in an operating state. Furthermore, since the charge control circuit 7b is on and the charge control circuit 7a is off, the power of the fuel cell unit 11 supplied via the connector 16 charges the Li ion battery 18b via the charge control circuit 7b.

  At this time, the current integration circuit 20b measures the charging current and time of the Li ion battery 18b in detail, and the power management circuit 21 calculates the remaining amount of the Li ion battery 18b based on these pieces of information. Further, the integrated value of the charging current of the Li-ion battery 18b is regarded as the amount of power generated by the DMFC 12, and the measured amount for each fixed time is recorded in the memory 63 and iVDR 47 (see FIG. 6) together with the date and time. Then, the power management circuit 21 compares the previous power generation amount with the current power generation measurement amount, and the current power generation measurement amount is lower than a predetermined amount that is set to a value lower than the rated value. If it is determined that the DMFC 12 has deteriorated.

  On the other hand, in this state (that is, the charged state of the Li ion battery 18b in the period T2), the discharge switch 8b is on, and the Li ion battery 18a is connected to the DC / DC converter 9 via the discharge switch 8b. As a result, the charge of the Li ion battery 18a is discharged to the load 10 through the path of the discharge switch 8b. At this time, the output current of the Li-ion battery 18a is detected by the current integration circuit 20a and managed by the power management circuit 21. Therefore, as a result, as shown in the period T2 in FIG. 8, the remaining capacity of the Li ion battery 18b increases by DMFC charging, and the remaining capacity of the Li ion battery 18a decreases. In addition, since there is almost no power consumption in the DMFC charged state in the backyard, the decrease in the remaining capacity of the Li ion battery 18a is small. However, when the portable information terminal 50 is rented out at the beginning of the period T3 and the power is turned on, the power consumption is increased. Therefore, the degree of decrease in the remaining capacity of the Li ion battery 18a is increased. growing. In addition, since the DMFC charging to the Li ion battery 18b is not different from the period T2 in the period T3 in the operating state, the charging curve of the Li ion battery 18b is in an extended state from the period T2.

  Next, when the portable information terminal 50 reads information from the RFID chip 53 at the beginning of the period T4 at the return window 56, the state of the Li ion battery 18a and the Li ion battery 18b is changed when the operating state shifts to the standby state. Switches. That is, in the standby state of the period T4, the Li ion battery 18a is in the DMFC charged state, the Li ion battery 18b is connected to the load, and the portable information terminal 50 moves in the backyard. At this time, the power management circuit 21 grasps the states of the Li-ion battery 18a and the Li-ion battery 18b. First, the charge control circuit 7b is turned off, the discharge switch 8c is turned on, and the DC / DC converter 9 is turned on from the Li-ion battery 18b. Ensure a discharge route to. Then, the discharge switch 8b is turned off to cut off the discharge route from the Li ion battery 18a, and the operation of the charge control circuit 7a is turned on.

  At this time, since the AC adapter 2 is not connected, the state control signal 17 is on, and the power from the fuel cell unit 11 is supplied to the Li ion battery 18a via the step-up DC / DC converter 15 and the charge control circuit 7a. Charged. As a result, as shown in the period T4 in FIG. 8, the remaining capacity of the Li ion battery 18a increases and the remaining capacity of the Li ion battery 18b decreases. At this time, since there is little power consumption in the backyard period in the period T4, the decrease in the remaining capacity of the Li ion battery 18b is small, but the operation in the period T5 after lending the portable information terminal 50 to the visitors. Since the power consumption increases at times, the degree of decrease in the remaining capacity of the Li ion battery 18b increases. In the period T6, similarly to the period T2, the portable information terminal 50 is returned and the charge / discharge states of the Li ion battery 18a and the Li ion battery 18b are switched, and in the backyard, the Li ion battery 18b becomes the DMFC charged state and the Li ion The battery 18a is connected to the load.

  Thus, in the normal use state, operation is performed while switching the charge / discharge state of the Li-ion battery 18a and the Li-ion battery 18b every time the portable information terminal 50 is returned, which is the timing of transition from the operating state to the standby state. Therefore, the change tendency of the remaining capacity of the two sets of Li ion batteries will decrease as a whole as shown in the graph of FIG. Note that the switching timing of the Li-ion battery may be performed every predetermined time by a timer, or another event, for example, a visitor holds the portable information terminal 50 over a predetermined RFID chip in the field. Switching may be performed according to the timing at which the information on the IC chip is read. Note that when switching is performed based on the SOC determination having the remaining amount management function, switching is performed so that the Li-ion battery with the smaller remaining capacity is always in the DMFC charged state. For this reason, in the embodiment shown in FIG. 8, the Li ion battery 18a and the Li ion battery 18b are alternately charged and discharged, but the Li ion battery in a state near full charge is never in the DMFC charged state. Depending on the situation, there may be a utilization form in which one Li ion battery is continuously charged or discharged.

  That is, for the Li-ion battery 18a and the Li-ion battery 18b, the charge state and the discharge state are always clearly separated, so the remaining amount management is easy, and the overall battery capacity of the combined Li-ion battery is effective. Can be used for Moreover, it can be used safely so as not to cause a problem for the Li ion battery itself. Furthermore, since there is no direct power path from the DMFC 12 to the load 10, the state of the DMFC 12 does not directly affect the load 10, so that the portable information terminal 50 can be driven stably.

  Next, when the portable information terminal 50 is not used at night or on closed days, the portable information terminal 50 is accommodated in the charging rack 58 as shown in FIG. 1, and AC charging by the commercial power source 1 as shown in FIG. Is performed. At this time, the AC adapter 2 is connected to the commercial power source 1 and is connected to the portable information terminal 50 via the connector 3. In the portable information terminal 50, the voltage monitoring circuit 4 recognizes the input voltage and turns off the state control signal 17. As a result, the step-up DC / DC converter 15 stops and the power from the DMFC 12 is not input to the main unit 6. In this state, the charge control circuit 7a and the charge control circuit 7b are on, the discharge switch 8a is on, and the discharge switch 8b and the discharge switch 8c are off.

  Therefore, the electric power input from the AC adapter 2 is input to the charge control circuit 7a and the charge control circuit 7b via the diode 5, and charges the Li ion battery 18a and the Li ion battery 18b, respectively. Furthermore, the electric power input from the AC adapter 2 is supplied to the load 10 via the discharge switch 8 a and the DC / DC converter 9. In this state, the load 10 is in a sleep state, and the input power from the AC adapter 2 is mainly used for charging the Li ion battery 18a and the Li ion battery 18b. That is, when the portable information terminal 50 is inserted into the connector 3 provided on the charging rack 58 and AC charging is started, the backlight 67 of FIG. 6 is automatically turned off and the charging mode is entered. As a result, there is no need to worry about forgetting the power off and consuming unnecessary energy, and the convenience of the staff handling a large number of portable information terminals is improved.

  In FIG. 4, when the portable information terminal 50 is removed from the connector 3 of the AC adapter 2, the power is automatically turned on to enter the self-diagnosis mode, and the remaining amount of the Li ion battery 18a and the Li ion battery 18b. If a check is made and there is no abnormality, the backlight 67 (see FIG. 6) is turned off and the DMFC 12 is awaiting activation. Furthermore, for the Li-ion battery 18a and the Li-ion battery 18b, the dedicated charge control circuit 7a and the charge control circuit 7b can be optimally charged while observing the state of the Li-ion battery, so that the battery can be easily managed and deteriorated. There is no worry about overcharging. In addition, this state is a state where power from the AC adapter 2 can be supplied even when both the Li ion battery 18a and the Li ion battery 18b are completely discharged. can do.

FIG. 13 is a view showing a modification of the power supply circuit system in FIG. 4, and members having the same reference numerals as those in the power supply circuit system in FIG. In FIG. 13, the wiring from the connector 16 and the wiring from the AC adapter 2 to the charging control circuits 7a and 7b are different from each other. In this embodiment, the charging control circuits 7a and 7b compare the voltage from the connector 16 (that is, the output voltage of the step-up DC / DC 15) with the voltage from the AC adapter 2, and adopt a higher voltage input. And
For example, by setting the output of the AC adapter 2 to 5.5V and the output of the DMFC step-up DC / DC15 to 4.5V, the commercial power supply 1 is usually used even if the forward voltage drop 0.7V of the diode 5 is taken into consideration. When connected, since the voltage of the AC adapter 2 becomes higher than the voltage from the connector 16, the power from the AC adapter 2 is automatically adopted. As a result, the control burden on the power management circuit 21 can be reduced.

Then, the charge control circuits 7a and 7b and the discharge switches 8b and 8c transmit signals indicating the switching state of these switches bidirectionally to and from the power management circuit 21, so that the power management circuit 21 can be connected to the portable information terminal 50. It becomes possible to recognize the power supply status.
Although the charge control circuits 7a and 7b and the discharge switches 8b and 8c are described as separate block circuits, the charge control circuit 7a and the discharge switch 8b, and the charge control circuit 7b and the discharge switch 8c are configured as one integrated circuit. It is also possible to do.

FIG. 5 is a circuit diagram showing in detail a circuit provided in the fuel cell unit in the circuit configuration of the power supply system shown in FIG.
In FIG. 5, a thermistor 34 is connected to the DMFC 12, and temperature information detected by the thermistor 34 is input to the boost converter control circuit 30. The DMFC 12 is connected to the OCV protection circuit 14 via the connector 13. The OCV protection circuit 14 includes a bridge circuit including a shunt regulator 22 and resistors 23, 24, and 25. The OCV protection circuit 14 is connected to the step-up DC / DC converter 15. The step-up DC / DC converter 15 includes an n-channel power MOSFET 28, a p-channel power MOSFET 29, an inductor 27, a smoothing capacitor 33, a step-up converter control circuit 30, a current sensor 26, an input current control circuit 31, and an output voltage control circuit 32. It has a configuration. The step-up DC / DC converter 15 is connected to the main unit 6 shown in FIG.

  Next, the operation of the fuel cell unit 11 shown in FIG. 5 will be described. The output voltage of the DMFC 12 is compared with the reference voltage of the shunt regulator 22 as a voltage dividing ratio of the resistors 24 and 25. Therefore, when the output voltage of the DMFC 12 is less than or equal to a predetermined value, the impedance of the shunt regulator 22 becomes very high and no current flows through the resistor 23. However, when the open circuit voltage (OCV) of the DMFC 12 exceeds a predetermined value, the impedance of the shunt regulator 22 decreases rapidly and a current flows through the resistor 23.

  The current-voltage characteristic of the DMFC 12 has a high open-circuit voltage when the current is zero, but has a characteristic that the voltage greatly decreases when even a little current flows. Therefore, the circuit configuration of the OCV protection circuit 14 can keep the output voltage of the DMFC 12 below a predetermined value regardless of the state of the main unit 6 in FIG. 4, and the boost DC / DC converter 15 and the main unit can be increased by increasing the open circuit voltage. It is possible to prevent the unit 6 from being damaged.

  Next, a control method of step-up DC / DC converter 15 shown in FIG. 5 will be described. The step-up DC / DC converter 15 alternately switches the n-channel power MOSFET 28 and the p-channel MOSFET 29 by the boost converter control circuit 30, whereby the energy stored in the inductor 27 when the n-channel power MOSFET 28 is turned on is stored in the p-channel power MOSFET 29. This circuit increases the output voltage from the input voltage of the step-up DC / DC converter 15 by shifting to the smoothing capacitor 33 when turned on.

  In the first embodiment, the output voltage of the step-up DC / DC converter 15 is set to 4.5V to 5.0V. The step-up DC / DC converter 15 feeds back the voltage of the smoothing capacitor 33 to the output voltage control circuit 32 and controls the output voltage to be constant in the range of 4.5V to 5.0V. Further, the current flowing through the inductor 27 is detected by the current sensor 26 and input to the input current control circuit 31. The input current control circuit 31 has no output signal when it is equal to or less than a predetermined current value (ILim), and the boost converter control circuit 30 operates only by the output signal of the output voltage control circuit 32 described above, and the n-channel power The on / off ratio of each gate circuit of the MOSFET 28 and the p-channel power MOSFET 29 is controlled.

  However, when the current detected by the current sensor 26 exceeds a predetermined value (ILim), the output signal of the input current control circuit 31 changes, so that the boost converter control circuit 30 receives the output signal of the output voltage control circuit 32 from the output signal. Thus, the output signal of the input current control circuit 31 is preferentially inputted, and the operation is performed so that the input current ILim is limited to a constant value. As a result, the output current of the DMFC can always be kept below a predetermined value, and various phenomena such as a decrease in output due to bubbles inside the DMFC, condensation at the air electrode due to increased entrained water, and water leakage can be prevented. The portable information terminal 50 can be used stably for a long time.

  In the charging control method shown in FIG. 5, the input current control circuit 31 limits the current of the DMFC 12. Therefore, in the circuit configuration simply DMFC 12 -step-up DC / DC converter 15 -load 10, Since it is not possible to follow the change of the above, stable operation cannot be performed. However, in the charge control system of the first embodiment, as shown in FIG. 4, the direct load of the DMFC 12 is always a Li ion battery, and the load 10 is connected to the other Li ion battery. The load current 10 is not affected by the output current limitation of the DMFC 12.

  Next, the temperature protection function is described. Since the DMFC 12 is provided with the current limiting function as described above, it always operates at a stable operating point. However, as shown in FIG. 5, the thermistor 34 is in contact with the DMFC 12 and detects the temperature. Even if the DMFC 12 is overheated and exceeds a predetermined temperature, the temperature information is input to the boost converter control circuit 30 to stop the switching of the boost DC / DC converter 15 and shut down the converter operation. Since this temperature protection function has a temperature hysteresis, when the DMFC 12 is sufficiently cooled by stopping the converter operation, it is automatically restarted.

  In the first embodiment, the p-channel power MOSFET 29 can also be realized by a Schottky barrier diode. Depending on the configuration of the boost converter control circuit 30, the n-channel power MOSFET 28 can also use a Schottky barrier diode. Of course, the n-channel power MOSFET 28 and the p-channel power MOSFET 29 may be other power semiconductor devices. The shunt regulator 22 can also be configured by a general comparator and a reference power source. Furthermore, the current sensor 26 can be realized by various current detection means such as detection using a shunt resistor, a Hall element, or a sensor MOSFET built in the n-channel power power MOSFET 28. The insertion position of the current sensor 26 may be on the input side of the inductor 27, or may be inserted between the ground side, that is, between the source electrode of the n-channel power MOSFET 28 and the ground side of the resistor 25.

  In FIG. 5, the step-up DC / DC converter 15 is connected to the subsequent stage of the OCV protection circuit 14, but the step-up DC / DC converter 15 is directly connected to the output terminal of the DMFC 12, and the OCV protection circuit is connected in parallel to the connection point. Even if connected, the circuit configuration is the same. Further, when the DMFC 12 is overheated, the output voltage of the step-up DC / DC converter 15 may be reduced by operating similarly to the input current control circuit 31. The iVDR 47 (see FIG. 6) in the first embodiment does not need to be a hard disk, and may be another recording medium such as an optical disk.

<Second Embodiment>
Next, a method for diagnosing a portable information terminal according to the second embodiment of the present invention will be described with reference to FIGS. 1, 4, 5, 11, and 12. FIG. 11 is a diagram showing an outline of a procedure related to DMFC state grasping and power generation retry according to the portable information terminal of the second embodiment of the present invention.
First, with reference to FIG. 11, an overview of the status grasp in the power supply system of the portable information terminal and the power generation retry of the DMFC will be described.

  In the procedure shown in FIG. 11, the DMFC 12 is stopped (step S41), and the normal charging state in which either the Li ion battery 18a or the Li ion battery 18b is charged by the DMFC 12 is entered. At this time, the Li ion battery 18a or the Li ion battery 18b is charged with the charging current command value Ic of the rated value I1 (step S42). Here, when the PG signal from the DMFC 12 becomes L, in other words, when the output voltage of the step-up DC / DC converter 15 decreases (step S43), the charging current command value Ic to the Li ion battery 18a or the Li ion battery 18b is set. The charging is changed to the rated value I2 smaller than the rated value I1 and the aging mode charging is continued (step S44). Then, after charging in the aging mode is continued for 60 seconds, the charging current command value Ic is returned to the rated value I1 again (step S45), and the process proceeds to normal charging (step S42). Such a cycle is repeated 30 times, and the 31st time is processed as a DMFC abnormality (step S46).

  Further, when the PG signal from the DMFC 12 is L in the charging state of the aging mode in step S44, that is, when the output voltage of the step-up DC / DC converter 15 decreases (step S47), the step-up DC / DC converter 15 is stopped. To enter standby mode to stop charging. Of course, at this time, the charging current command value Ic to the Li ion battery 18a or the Li ion battery 18b is 0 (step S48). Then, after the activation standby state has elapsed for 20 seconds, the charging current command value Ic is returned from 0 to a smaller rated value I2 (step S49), and the aging mode is entered (step S44). Such a cycle is repeated 10 times, and the 11th time is processed as a DMFC abnormality (step S46).

  Such a procedure always changes when the visitor uses the portable information terminal 50 or not. At this time, since the stable electric power is always supplied from the Li ion battery 18a or the Li ion battery 18b to the load system of the portable information terminal 50, the transition of the procedure is not affected at all. Further, even when the DMFC transitions to an abnormal state, the abnormality is not displayed on the portable information terminal 50, and the abnormality of the DMFC 12 is recorded in the memory 63 and the iVDR 47 (see FIG. 6) together with the date and time as described above. . In FIG. 1, the abnormality is displayed for the first time in the self-diagnosis mode when the power supply at the rental counter 55 is turned on or the power supply at the return counter 56 is turned off. Thereby, the trouble of a power supply system does not generate | occur | produce while using the portable information terminal 50 of a visitor.

Next, with reference to FIG. 12, the details of the state grasp in the power supply system of the portable information terminal and the power generation retry of the DMFC 12 will be described.
FIG. 12 is a diagram showing details of procedures related to DMFC state grasping and power generation retry according to the portable information terminal of the second embodiment of the present invention. 12, ACC corresponds to the ACC signal 35 in FIGS. 4 and 5, and is output from the power management circuit 21 to the boost DC / DC converter 15 of the fuel cell unit 11. That is, H is output when the operation of the DMFC 12 is permitted, and L is output when an instruction to stop the operation of the DMFC 12 is issued. PG corresponds to a PG signal (logic signal) 36 and is output from the step-up DC / DC converter 15 of the fuel cell unit 11 to the power management circuit 21. That is, H is output if the output voltage of the boost DC / DC converter 15 is a predetermined value, and L is output in the case of an abnormal state such as a decrease in the output of the boost DC / DC converter 15. Ic is a charging current command value of the charging control circuit 7a and the charging control circuit 7b output from the power management circuit 21.

  In FIG. 12, the portable information terminal 50 is initially in a DMFC stop state. At this time, the ACC signal is L, the PG signal is L, and the charging current command value Ic is 0 (step S51). At startup, the charging current command value Ic is set to the rated value I1 (first charging current command value), the ACC signal is set to H, and the step-up DC / DC converter 15 is operated (step S52) to enter the normal charging mode. Transition. In the normal charging mode, the Li ion battery 18a or the Li ion battery 18b is charged with the power generated by the DMFC 12. At this time, since the output voltage of the step-up DC / DC converter 15 is a predetermined value, the PG signal outputs H (step S53).

  At this time, the power management circuit 21 monitors the PG signal. If the PG signal becomes L (step S54), the power management circuit 21 makes a transition to the overload (1) mode. In this overload (1) state, the ACC signal is H, the PG signal is L, and the charging current command value Ic is the rated value I1 (step S55). The overload (1) means that the charging power is larger than the power generation amount of the DMFC 12 because the DMFC 12 is not activated sufficiently.

Therefore, the charging current command value Ic is changed to a rated value I2 (second charging current command value) that is sufficiently smaller than the rated value I1, for example, ½ or less of the rated value I1 (step S56), and the aging mode is set. Transition. In the aging mode, the ACC signal is H, the PG signal is H, the charging current command value Ic is a small rated value I2, and is kept for 60 seconds (step S57). The small rated value I2 is set to about 1/5 of the rated value I1, for example. Here, the aging mode is a mode in which a current having a reasonable current density is taken out from the DMFC 12 and the power generation characteristics are improved at an early stage from the deterioration of the power generation characteristics due to the temperature rise.

  Next, in the aging mode, after 60 seconds, the charging current command value Ic is increased from the small rated value I2 to the rated value I1 (step S58), and the mode is changed to the normal charging mode. Such mode transition is performed up to 30 times. Therefore, when the PG signal becomes L, the charging current command value Ic is again lowered to a small rated value I2, and the DMFC 12 is started and accelerated in the aging mode. Further, when it is found that the PG signal is L in the aging mode (step S59), the mode shifts to the overload (2) mode. At this time, the ACC signal is H, the PG signal is L, and the charging current command value Ic is the command value I2 (step S60).

  Then, the step-up DC / DC converter 15 is stopped by setting the ACC signal to L, and at the same time, the charging current command value Ic is also set to 0 to stop the charging (step S61), and the start standby mode is entered. In the start standby mode, the ACC signal is L, the PG signal is L, and the charging current command value Ic is 0, and is kept for 20 seconds (step S62). In this start standby mode, the charging current command value Ic is set to a small rated value I2 after 20 seconds while the ACC signal is L, and the mode is shifted to the aging mode (step S63). Such mode transition is performed up to 10 times.

  In addition, when the ACC signal becomes L during normal charging in step S53 (step S64), when the ACC signal becomes L during overload (1) in step S55 (step S65), and when overload occurs in step S60 (step S65). When the ACC signal becomes L in 2) (step S66), the DMFC 12 is stopped (step S51). Furthermore, in the aging mode of step S57, when the ACC signal becomes L at the 31st loop, it is determined that the DMFC is abnormal (step S67). Further, in the start standby mode of step S62, if the 11th loop is reached, it is determined that the DMFC is abnormal (step S68).

<Summary>
As described above, according to the portable information terminal of the present invention, AC charging is not required during daytime operation in the exhibition hall, so that the troubles in lending and returning the portable information terminal are eliminated. In addition, when the portable information terminal is lent, the power is turned on simply by pressing a button, and an explanation screen for the attendee is automatically displayed, thereby reducing the burden on the attendant. Furthermore, since the self-diagnosis and power-off can be surely performed by reading a predetermined RFID chip when the portable information terminal is returned, the operation of the staff can be simplified and the power-off can be prevented. In addition, since the state of the two systems of Li-ion batteries is automatically switched by SOC determination (remaining capacity determination), the Li-ion battery whose remaining capacity has been reduced by using can be put into charge mode immediately after use, The output power from the DMFC 12 is not wasted.

  In addition, since the load of the portable information terminal has a circuit configuration that is not directly connected to the DMFC, the load-side device can be driven stably regardless of the state of the DMFC. Further, the Li-ion battery can be AC charged efficiently from a commercial power source, and exclusive charging control is performed so that the output current from the DMFC 12 automatically becomes zero when charging from the commercial power source. Therefore, it is not necessary for the staff to perform the DMFC on / off operation at the start of AC charging each time, and the usability of the portable information terminal is further improved. Further, in the portable information terminal of the present invention, each of the plurality of Li ion batteries includes a charge control circuit, a voltage monitoring circuit, and a current integration circuit, so that the state of each Li ion battery is detected in detail. Detailed power management can be performed while grasping. As a result, since the deterioration of the Li ion battery can be suppressed and the replacement cycle of the Li ion battery can be lengthened, the running cost can be kept low.

  In addition, since it has a function of limiting the output current of the DMFC to a predetermined value or less, it is possible to prevent the DMFC from deteriorating and prevent water from being generated from the electrode and overheating. The terminal can be used safely. Furthermore, even if the DMFC is abnormally overheated, the portable information terminal can be used safely because it has a protection function such as a thermistor. As a result, it is possible to provide a suitable system even when a large number of portable information terminals equipped with DMFC are operated for a long period of time at exhibitions or exhibitions.

  According to the portable information terminal of the present invention, a fuel cell and a plurality of secondary batteries (for example, lithium ion batteries) are used. The secondary battery supplies power to the load of the portable information terminal. For this reason, since there is no worry of running out of the battery while using the portable information terminal, the portable information terminal can be used as a portable information terminal suitable for operating for a long period of time at an exhibition or exhibition.

It is explanatory drawing which shows the operating method of the portable information terminal mounted with a fuel cell in the present invention. It is a figure which shows the external appearance of a portable information terminal. It is AA sectional drawing of the portable information terminal shown in FIG. It is a figure which shows the power supply circuit type | system | group of the portable information terminal in this invention. FIG. 5 is a circuit diagram showing in detail a circuit provided in the fuel cell unit in the circuit configuration of the power supply system shown in FIG. 4. It is a functional block diagram which shows the structure of the control unit in a portable information terminal. It is a figure which shows transition of the total value of the input-output electric power of Li ion battery mounted in the portable information terminal in this invention, and Li ion battery remaining capacity. The relationship between the state of a portable information terminal and charging / discharging of two sets of Li ion batteries is shown. It is a flowchart which shows the flow at the time of rental of the portable information terminal to the visitor in the rental window in the operation method of the portable information terminal shown in FIG. It is a flowchart which shows the flow at the time of return of the portable information terminal from the visitor in the return window in the operating method of the portable information terminal shown in FIG. It is a figure which shows the outline | summary of the procedure regarding DMFC state grasp and power generation retry concerning the portable information terminal of the second embodiment of the present invention. It is a figure which shows the detailed content of the procedure shown in FIG. It is a figure which shows the modification of the power supply circuit system in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 AC adapter 3 Connector 4 Voltage monitoring circuit 5 Diode 6 Main body unit 7a, 7b Charge control circuit (charging means)
8a, 8b, 8c Discharge switch 9 DC converter 10 Load 11 Fuel cell unit 12 DMFC
DESCRIPTION OF SYMBOLS 13 Connector 14 OCV protection circuit 15 DC converter 16 Connector 17 State control signal 18a Li ion battery 18b Li ion battery 19a Voltage monitoring circuit 19b Voltage monitoring circuit 20a Current integration circuit 20b Current integration circuit 21 Power management circuit 22 Shunt regulator 23 Resistance 24 Resistance 25 Resistance 26 Current sensor 27 Inductor 28 n-channel power MOSFET
29 p-channel power MOSFET
30 Boost converter control circuit 31 Input current control circuit 32 Output voltage control circuit 33 Smoothing capacitor 34 Thermistor 35 ACC signal 36 PG signal (logic signal)
40 Fuel Confirmation Window 41 Port 42 Air Hole 43 Button 44 Button 45 Liquid Crystal Screen (Display Means)
46 RFID antenna 47 iVDR
48 Cartridge exchange port 50 Portable information terminal 51a, 51b, 53 RFID chip 52a, 52b Exhibit 52b Exhibit 54 Cart 55 Rental counter 56 Return counter 58 Charging rack 59 Entrance 60 Exit 61 Exhibition hall 62 CPU
63 Memory (storage means)
64 connector 65 iVDR interface 66 backlight controller 67 backlight 68 LCD controller 69 RFID reader 70 bus controller I input current I1 rated value I2 rated value Ic charging current command value

Claims (9)

A portable information terminal that provides desired information,
A plurality of sets of secondary batteries that are charged and discharged independently;
A fuel cell for charging the secondary battery;
Display means for displaying information in an operating state of the portable information terminal and not displaying information in a standby state for stopping the operation of the portable information terminal;
Self-diagnosis is performed by an operation of transitioning from the operating state to the standby state.If there is no abnormality, the state is shifted to the standby state as it is, and if there is an abnormality, the abnormality content is displayed on the display means .
During charging by the fuel cell, the state of the fuel cell is grasped, and when the fuel cell becomes abnormal, the abnormality information of the fuel cell is stored in the storage means, and the state of the portable information terminal A portable information terminal characterized in that the abnormality information is displayed on the display means at the time of the next self-diagnosis performed based on an operation of transitioning . Self-diagnosis is performed by an operation of transitioning from the standby state to the operating state, and when there is no abnormality, the state is shifted to the operating state as it is to display the initial screen on the display means. The portable information terminal according to claim 1, wherein the portable information terminal is displayed on a display means. A portable information terminal that provides desired information,
A plurality of sets of secondary batteries that are charged and discharged independently;
A fuel cell for charging the secondary battery;
Charging means for individually charging the plurality of sets of secondary batteries from the fuel cell;
And a step-up DC / DC converter that Mashimasu through between the charging means and the fuel cell,
The step-up DC / DC converter has a shutdown function for stopping the operation of the step-up DC / DC converter when an abnormal voltage occurs in the fuel cell.
A first charging current command value transmitted by the charging means and a second charging current command value equal to or less than ½ of the first charging current command value;
Based on the logic signal corresponding to normal / abnormal of the output voltage of the step-up DC / DC converter,
During the charging by the fuel cell, the secondary battery is charged by the first charging current command value,
When the logic signal is a signal indicating an abnormality of the step-up DC / DC converter, the charging current command value is changed to the second charging current command value and the secondary battery is charged for a predetermined time. Then, after the predetermined time elapses, the charging current command value is changed to the first charging current command value again to charge the secondary battery . The portable information terminal according to any one of claims 1 to 3, wherein the power capacity of the fuel cell is less than an average power consumption in an operating state in which the portable information terminal is operated . A plurality of sets of secondary batteries that are charged and discharged independently , a fuel cell, charging means for charging the secondary battery from the fuel cell, and step-up DC / DC interposed between the fuel cell and the charging means a DC converter, a self-diagnosis method for a portable information terminal having a step-up DC / DC converter having a function of stopping the abnormal voltage occurs during the step-up DC / DC converter operation of the fuel cell,
Corresponding to a first charging current command value transmitted by the charging means, a second charging current command value smaller than the first charging current command value, and normal / abnormal of the output voltage of the step-up DC / DC converter Using logic signals,
Charging the secondary battery with the first charging current command value during charging by the fuel cell;
When the logic signal is a signal indicating an abnormality of the boost DC / DC converter, and change the charge current command value to said second charging current command value, charging the secondary battery for a predetermined time And the steps to
After the predetermined time has elapsed, again, the charge current command value is changed to the first charge current command value to charge the secondary battery;
A self-diagnosis method for a portable information terminal, comprising:   6. The self-diagnosis method for a portable information terminal according to claim 5, wherein the second charging current command value is ½ or less of the first charging current command value. When the change operation of the charging current command value becomes a predetermined number of times or more, the abnormality information of the fuel cell is stored in the storage means, and the operating state of the portable information terminal and the operation of the portable information terminal are stopped. 7. The self-diagnosis method for a portable information terminal according to claim 5, wherein the abnormality information is displayed at the time of the next self-diagnosis performed based on an operation of changing the state between the standby state and the standby state .   When the charging current command value is the second charging current command value and the logic signal corresponds to an abnormality in the boost DC / DC converter, the charging unit and the boost DC / DC converter are stopped. 8. After the predetermined time has elapsed, the step-up DC / DC converter is operated again and the secondary battery is charged with the second charging current command value. A self-diagnosis method for a portable information terminal according to claim 1. When the charging unit stops more than a predetermined number of times, the abnormality information of the fuel cell is stored in the storage unit, and the operation state of the portable information terminal and the standby state in which the operation of the portable information terminal is stopped 9. The portable information terminal self-diagnosis method according to claim 8, wherein the abnormality information is displayed at the time of the next self-diagnosis performed based on an operation of changing the state between the two .

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