JP2016201023A - Method of assisting management of stylus pen, computer program, and mobile electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of assisting a user who manages a stylus pen with a battery mounted thereon.SOLUTION: A display system 11 mounted on a tablet terminal is formed by laminating, from the top, a touch panel 21, a display 23, an electromagnetic-induction digitizer panel 25, and a shield panel 27. A stylus pen 100 transmits a battery level, together with operation information, to the digitizer panel periodically. The tablet terminal measures the time elapsed from receiving the battery level last, and displays a message indicating that the stylus pen has been lost on the display when the battery level is equal to or more than a predetermined threshold and the lapse time exceeds a predetermined value.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technique for assisting a user in managing a stylus pen equipped with a battery.

  A portable electronic device such as a tablet terminal, a smartphone, or a notebook personal computer may be equipped with a coordinate input device called a digitizer as an input device. The digitizer uses a stylus pen for input. By configuring a display device that combines a digitizer and a touch screen, the user can operate the display device with either a stylus pen or a finger.

  One of the operating principles of the digitizer is an electromagnetic induction type. An electromagnetic induction type digitizer uses an electromagnetic wave propagating between a digitizer panel and a stylus pen, and a coil array arranged on the digitizer panel detects the position of the stylus pen. Using the digitizer allows the system to recognize handwritten characters and figures drawn on the digitizer panel with a stylus pen. The digitizer also generates pen pressure data from the pressure detected by the stylus pen in order to make the system recognize the thickness of the line that is close to the pen pressure sensation when writing characters on paper.

  There are two types of electromagnetic induction stylus pens: a passive type that operates with power received by electromagnetic induction from a digitizer panel, and an active type that operates with an internal battery or electric double layer capacitor (super capacitor). . It can be said that the stylus pen used instead of operating the touch screen with a finger belongs to the passive type in that no battery is mounted inside.

  Non-Patent Document 1 describes the principle of an electromagnetic induction type digitizer. This document describes a stylus pen that includes a battery and a digitizer that operates with a stylus pen that does not include a battery. Patent Document 1 discloses a position input device that includes a tablet that detects a signal transmitted by a pen-type position indicator having an electric double layer capacitor that stores electric power, and a monitor. When the holding voltage of the electric double layer capacitor gradually decreases, the position indicator sends a charge request signal to the tablet.

  The position input device displays a charge request message on the monitor based on the charge request signal for the tablet. A user who sees the display on the monitor can charge the position indicator. Further, this document describes that a charge request message is displayed on the monitor when a predetermined time has elapsed since the previous charge, even if there is no charge request from the position indicator. Patent Document 2 discloses a stylus pen equipped with a charging coil, an electric double layer capacitor, a voltage conversion circuit, and an oscillation circuit.

JP 2007-164356 A JP 2014-119936 A

Electromagnetic induction digitizer, [online], Wacom, [Search April 2, 2015], Internet, <URL: http://tablet.wacom.co.jp/what/news-img/W8002basis.pdf>

  Hereinafter, in this specification, the active stylus pen is simply referred to as a stylus pen. It is desirable for the user that the amount of electricity in the battery or the electric double layer capacitor is secured so that the stylus pen can be used whenever necessary. In the invention of Patent Document 1, since a prompt is displayed on the monitor when a charge request is made from the stylus pen, the user can know the timing of charging and the timing of battery replacement.

  However, the user may not charge at that time and may input from the touch screen for a while or not use the computer for several days. As a result, the next time you want to use the stylus pen, you may not be able to use it by natural discharge, or a sufficient amount of electricity may not be secured. Furthermore, since the user does not know the purchase method when the stylus pen is lost, the user may not use the digitizer thereafter. Further, since the battery mounted on the stylus pen is a special long and narrow alkaline battery called AAAA type, it is difficult for the user to obtain the battery, and the stylus pen may not be used with the battery life. Furthermore, it is convenient if it is possible to know that the battery has functioned normally by charging or replacement.

  Therefore, an object of the present invention is to provide a method for improving the convenience of a stylus pen. It is another object of the present invention to provide a method for assisting a user who manages a DC power source mounted on a stylus pen. Furthermore, the objective of this invention is providing the computer program which implement | achieves such a method, and a portable electronic device.

  The present invention provides a method in which a portable electronic device equipped with a display system that can be operated with a stylus pen including a DC power source assists the user in managing the DC power source. Periodically receive the remaining capacity of the DC power source from the stylus pen. Time elapsed after receiving the remaining capacity. When the remaining capacity is equal to or greater than the first threshold and the elapsed time exceeds a predetermined value, a message indicating the possibility of stylus pen loss is displayed on the display system. The user can check the location of the stylus pen by looking at the message and take necessary actions.

  Here, a non-rechargeable battery, a rechargeable battery, or an electric double layer capacitor can be employed as the DC power source having the characteristic of remaining capacity. If the display system includes an electromagnetic induction digitizer panel, the remaining capacity can be received through a communication path formed by the digitizer panel and the stylus pen. Therefore, it is not necessary to provide an interface for forming a dedicated communication path between the stylus pen and the portable electronic device.

  If the message includes guidance indicating how to purchase the stylus pen, the user can easily purchase. A message may be displayed on the display system indicating an increase in remaining capacity when the remaining capacity reaches a second threshold that is less than the first threshold. Here, the method for increasing the remaining capacity differs depending on the type of the DC power source. If the DC power source is a non-rechargeable battery, it can be replaced, and if it is a rechargeable battery or an electric double layer capacitor, it can be charged.

  If this message includes guidance indicating how to purchase a DC power source, the user can easily purchase even a special battery. When the remaining capacity reaches less than the third threshold which is smaller than the second threshold and the elapsed time exceeds a predetermined value, a message prompting the increase of the remaining capacity can be displayed on the display system. If this message is displayed when the stylus pen is not used, it is possible to prevent the operation from being stopped due to spontaneous discharge in the next use.

  When the remaining capacity becomes equal to or greater than the first threshold after displaying a message prompting the increase in the remaining capacity, a message indicating that the remaining capacity has been successfully increased can be displayed on the display system. When the remaining capacity is received, a packet containing the remaining capacity and the stylus pen identifier is received, and the elapsed time is measured and the remaining capacity is compared with the threshold value for each identifier. The remaining capacity can be managed even when the same stylus pen is used, or when the same stylus pen is used in a plurality of display systems.

  An object for confirming the state of the remaining capacity can be displayed on the display system, and a message indicating the state regarding the remaining capacity can be displayed on the display system in response to a touch operation on the object. In this case, the user can confirm the necessity of increasing the remaining capacity whenever necessary. The object can be displayed on the display system tool bar or can be called and displayed by the user.

  According to the present invention, a method for improving the convenience of a stylus pen can be provided. Further, according to the present invention, a method for assisting a user who manages a DC power source mounted on a stylus pen can be provided. Further, according to the present invention, it is possible to provide a computer program and a portable electronic device that realize such a method.

It is a figure which shows the external shape of the tablet terminal 10 as an example of a portable electronic device. 2 is a cross-sectional view for explaining the configuration of a display system 11. FIG. 2 is a functional block diagram for explaining an example of a configuration of a tablet terminal 10. FIG. 4 is a diagram for explaining an example of the configuration of a digitizer panel 25. FIG. 3 is a diagram for explaining an example of a configuration of a stylus pen 100. FIG. It is a figure for demonstrating the threshold value which manages the remaining capacity of the battery. 2 is a functional block diagram illustrating an example of a configuration of a stylus pen management system 200. FIG. 5 is a flowchart for explaining the operation of a stylus pen management system 200. It is a figure for demonstrating the message which the stylus pen management system 200 displays.

[Tablet terminal]
FIG. 1A is a plan view showing an outer shape of a tablet terminal 10 as an example of a portable electronic device, and FIG. 1B is a rear view. FIG. 2 is a cross-sectional view for explaining the configuration of the display system 11. The tablet terminal 10 is equipped with a display system 11, and a storage unit 13 stores a stylus pen 100 for operating a digitizer panel 25. In the present specification, the same elements are described with the same reference numerals assigned to the drawings.

  In FIG. 2, the display system 11 has a touch panel 21, a flat panel display 23 such as an LCD, an electromagnetic induction digitizer panel 25, and a shield panel 27 stacked from above. The surface of the display system 11 constitutes the operation surface 22 of the touch panel 21 and the digitizer panel 25. The display system 11 detects the approach of a finger to the operation surface 22 and the touch panel 21 generates coordinate data. The display system 11 detects the approach of the stylus pen 100 and the digitizer panel 25 generates coordinate data.

  FIG. 3 is a functional block diagram for explaining an example of the configuration of the tablet terminal 10. The tablet terminal 10 includes, for example, a system memory 51, a display 23, a touch panel 21, a digitizer panel 25, and a WPAN (Wireless Personal Area) in an embedded system (SOC) type embedded system (SOC) 50. Network (Network) module 53, WWAN (Wireless Wide Area Network) module 55, WLAN (Wireless Local Area Network) module 57, and SSD 59 are connected.

  The embedded system 50 includes a CPU core, a GPU, a memory controller, an I / O controller, a firmware ROM, and the like. The SSD 59 stores software such as application programs, operating systems, and device drivers executed by the CPU core. The SSD 59 also stores a management program 80 that implements the present invention. The WPAN module 53 performs short-range wireless communication according to any standard such as Bluetooth (registered trademark), infrared communication, or near field communication (NFC).

[Digitizer panel and stylus pen]
FIG. 4 is a diagram for explaining an example of the configuration of the digitizer panel 25. FIG. 5 is a diagram for explaining an example of the configuration of the stylus pen 100. In FIG. 5, a stylus pen 100 is formed with a pen tip 101 that indicates the coordinates of the digitizer panel 25 at the tip.

  The stylus pen 100 includes operation buttons 121 and 123 on the outside, and houses a pressure sensor 103, an antenna 105, a high frequency circuit 107, a modulation circuit 109, an MPU 111, and an AAAA type battery 113 therein. Instead of the battery 113, an electric double layer capacitor or a rechargeable battery can be mounted as a DC power source. The charging method of the electric double layer capacitor or the rechargeable battery is not particularly limited, and may be either a contact type or a non-contact type.

  The pressure sensor 103 detects the pressure (writing pressure) applied to the pen tip 101 when the stylus pen 100 is pressed against the operation surface 22. The battery 113 supplies power to each device. The MPU 111 periodically monitors the voltage of the battery 113 and calculates the remaining capacity Rb. The operation button 121 is operated by the user when changing the color of a line input by the stylus pen 100. The operation button 123 is operated by the user when erasing the line input to the digitizer panel 25. The functions of the operation buttons 121 and 123 can be set and changed in the device driver of the digitizer panel 25.

  The MPU 111 periodically generates a packet including input data generated according to the detected pressure of the pressure sensor 103, the remaining capacity Rb of the battery 113 and the operation of the operation buttons 121 and 123, and sends the packet to the modulation circuit 109. The packet also includes the stylus pen 100 identifier. The modulation circuit 109 modulates the carrier wave output from the high frequency circuit 107 with the packet data and transmits it from the antenna 105.

  The digitizer panel 25 includes a coil array 73 composed of sensor coils 73 that detect electromagnetic waves emitted by the antenna 105 of the stylus pen 100. In the coil array 73, n sensor coils 91-1 to 91-n are arranged at an equal pitch so as to overlap in order in the X-axis direction, and at an equal pitch so as to overlap in order in the Y-axis direction. m sensor coils 92-1 to 92-m are arranged.

  The selection circuit 71 sequentially selects the sensor coils 91-1 to 92-m one by one based on the selection signal received from the controller 77, and forms a loop circuit via the reception circuit 75. The receiving circuit 75 detects the induced voltage of the sensor coil, converts it into digital data, and sends it to the controller 77. The receiving circuit 75 demodulates the modulated induced voltage, restores the packet data, and sends it to the controller 77.

  Since the induced voltage increases as the distance between the sensor coil and the stylus pen 100 becomes shorter, the controller 77 specifies the sensor coil in the X-axis direction and the Y-axis direction that are located closest to the stylus pen 100. Thus, coordinate data can be generated. The controller 77 sends the generated coordinate data and the restored packet data to the embedded system 50.

  FIG. 6 is a diagram for explaining the remaining capacity management table 81 of the battery 113. The remaining capacity Rb exists between 100% immediately after the battery 113 is replaced with a new one and 0% of complete discharge. The management table 81 shows threshold values 1 to 3 in descending order of remaining capacity Rb. Level 1 in which the remaining capacity Rb is equal to or greater than the threshold value 1 corresponds to a state where there is no practical problem even if the remaining capacity is continued, and the user does not have to pay attention to the battery state.

  The level 3 in which the remaining capacity Rb is smaller than the threshold value 2 corresponds to a remaining capacity that the user should pay attention to when to replace the battery 113 in order to prevent the operation of the stylus pen 100 from being stopped during use. The level 4 in which the remaining capacity Rb is smaller than the threshold value 3 corresponds to a state in which the remaining capacity Rb is extremely small and it is better to replace the battery 113 as soon as possible to prevent the stylus pen 100 from being stopped unexpectedly. In one example, the management table 81 can be managed by a management program 80 executed by the tablet terminal 10. In another example, the management table 81 can be managed by the MPU 111 of the stylus pen 100.

  FIG. 7 is a schematic functional block diagram of the stylus pen management system 200. The stylus pen management system 200 includes a digitizer panel 25, a display 23, a receiving unit 201, a management unit 203, and a time measuring unit 205. The digitizer panel 25 periodically receives packets including operation information from the stylus pen 100 through a communication path formed by electromagnetic coupling when the stylus pen 100 starts access.

  The packet includes a header, operation data when the operation buttons 121 and 123 are operated, a remaining capacity of the battery 113, and an identifier of the stylus pen 100. The MPU 111 of the stylus pen 100 incorporates the remaining capacity into the packet as 8-bit data, for example. In another example, the MPU 111 holds the management table 81 and incorporates data indicating any one of the levels 1 to 4 in FIG. 6 as the remaining capacity Rb into the packet. When generating a fixed-length packet, the MPU 111 can incorporate the remaining capacity Rb into a packet that is periodically transmitted for input operation even if the value does not change. When generating a variable-length packet, the MPU 111 may incorporate the value into the packet only when the remaining capacity Rb changes.

  The receiving unit 201 can be configured by a device driver and the embedded system 50. The receiving unit 201 sends the packet received from the digitizer panel 25 to the management unit 203 and the time measuring unit 205. The timer unit 205 can be composed of an OS and the embedded system 50. The time measuring unit 205 measures the elapsed time after receiving the packet. Every time a new packet is received, the time measuring unit 205 measures a new elapsed time and notifies the management unit 203 of it.

  The management unit 203 can be composed of a management program 80, a management table 81, an OS, and the embedded system 50. The management unit 203 creates image data including the message shown in FIG. 9 based on the remaining capacity Rb included in the packet received from the reception unit 201, the elapsed time received from the time measurement unit 205, and the management table 81 shown in FIG. This is displayed on the display 23. The management unit 203 displays an object that can be touch-operated to display information related to the remaining capacity Rb of the battery 113 on the display 23.

  FIG. 8 is a flowchart for explaining the operation of the stylus pen management system 200. In block 301, the tablet terminal 10 starts operating, and shifts to a state where the stylus pen management system 200 can receive a packet. In block 303, the management unit 203 proceeds to block 305 when determining that a predetermined time set as several months has passed since the previous report of the remaining capacity Rb, and blocks when determining that it has not elapsed. 307. In block 305, the management unit 203 proceeds to block 351 when it determines that the remaining capacity Rb received last time is greater than or equal to the threshold 1, and proceeds to block 307 when it determines that the remaining capacity Rb is less than threshold 1.

  If the stylus pen 100 is not used for a long period of time even though there was sufficient level 1 remaining capacity in the previous report, the user lost the stylus pen 100 or the stylus pen 100 failed. There is a possibility that. Then, since the user does not know how to purchase the stylus pen 100, it is considered that the user has left the state. This state is not preferable because it deprives the user of an opportunity to use the stylus pen 100.

  In block 351, the management unit 203 displays on the display 23 a message indicating the possibility of loss as shown in FIG. 9A and the URL of the portal site for purchase. As a result, the user can easily purchase the stylus pen 100 by accessing the portal site. 9A to 9D can be translated into the language of the country where the tablet terminal 10 is used.

  In block 307, the management unit 203 proceeds to block 353 when determining that the remaining capacity Rb received last time is less than the threshold 3, and proceeds to block 309 when determining that the remaining capacity Rb is greater than or equal to the threshold 3. Even when the stylus pen 100 is not used, the remaining capacity Rb of the battery 113 is reduced by natural discharge. Further, since the remaining capacity Rb becomes zero by use, the user may not use the stylus pen 100 thereafter.

  Therefore, if several months have passed since the previous report in which the remaining capacity Rb was less than the threshold 3, there is a high possibility that the stylus pen 100 is in an unusable state when it is desired to use it. At this time, if the management unit 203 displays a prompt to replace the battery 113 as shown in FIG. 9C on the display 23 in block 353, the user can be given an opportunity to replace the battery. Since the battery 113 is not easily available in the market, it is desirable to display the URL of the portal site that can be purchased and the exchange method at the same time. Since the natural discharge occurs even when the stylus pen 100 is not used, this procedure may be executed regardless of whether the stylus pen 100 is used or not whenever the display system 11 is activated.

  At block 309, the stylus pen management system 200 starts periodic reception of packets generated by the stylus pen 100 for input operations. The stylus pen 100 incorporates an identifier and, as an example, a remaining capacity Rb indicating 0% to 100% in 256 stages into the packet. The stylus pen 100 may generate a dedicated packet for sending the identifier and the remaining capacity Rb. The receiving unit 201 receives coordinate data and packet data from the controller 77 of the digitizer panel 25 and sends them to the management unit 203 and the time measuring unit 205.

  The management unit 203 manages packet data for each identifier, so that the battery status can be managed for each stylus pen even when a plurality of stylus pens access the digitizer panel 25. . In block 311, the timer unit 205 starts a process of measuring the time elapsed since the packet data was received and sending it to the management unit 203.

  In block 313, when the management unit 203 refers to the management table 81 and determines that the remaining capacity Rb is equal to or greater than the threshold value 1, the management unit 203 proceeds to block 357. When the battery 113 is normally exchanged in block 353, the remaining capacity Rb becomes equal to or greater than the threshold 1 in this report. In block 357, if the remaining capacity Rb from the previous report is less than the threshold 3, the management unit 203 confirms that the replacement of the battery 113 has been correctly completed on the display 23 as shown in FIG. Display the message that indicates. Thus, it is possible to prevent the user from leaving a state where the stylus pen 100 does not operate even though the battery 113 is replaced.

  When the management unit 203 determines in block 315 that the remaining capacity Rb is less than the threshold 2, the process proceeds to block 317. In block 317, the management unit 203 displays a prompt for prompting replacement of the battery 113 as shown in FIG. It is desirable to display the URL of the portal site that can be purchased and the exchange method at the same time as the block 353 in the prompt.

  Note that the management unit 203 may execute the procedure of FIG. 8 every time the display system 11 is activated, or may be executed every several activations. Or the management part 203 may perform the procedure of block 351,353,317 only once. Further, the display may include an icon for stopping the next and subsequent displays. The management unit 203 displays an object for confirming the state of the battery 113 on the display 23, and displays the current state of the battery 113 when the user touches the object with a finger or the stylus pen 100. May be.

  As an example, the state of the battery 113 is displayed as “Your pen battery condition is GOOD!” When the remaining capacity Rb is greater than or equal to the threshold value 2, and “Your pen battery is LOW! "Is displayed. When the threshold value is less than 3," Your pen battery is critical LOW! "Can be displayed. As a result, the user can check the state of the battery 113 whenever necessary.

  The procedure described in FIG. 8 is an example of the present invention, and the scope of the present invention is as set forth in the claims. For example, it is not necessary to employ all the procedures of blocks 351, 353, 359, and 317. Further, the stylus pen 100 may hold the management table 81 and send one of level 1 to level 4 as the remaining capacity. In this case, the amount of data to be transmitted can be reduced. Furthermore, although the example in which the stylus pen 100 transmits a packet to the digitizer panel 23 by electromagnetic induction has been described, the present invention relates to a short-range wireless communication system such as the Bluetooth (registered trademark) or USB. It can also be applied when installing and sending packets to tablet devices.

  Further, a rechargeable battery or an electric double layer capacitor can be used instead of the non-rechargeable AAAA battery. In this case, in blocks 353 and 317, a charging request prompt is displayed instead of the battery replacement prompt. Further, the predetermined time determined in block 303 can be changed to a value corresponding to the operation time in one charge.

  Although the present invention has been described with the specific embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and is known so far as long as the effects of the present invention are achieved. It goes without saying that any configuration can be adopted.

DESCRIPTION OF SYMBOLS 10 Tablet terminal 11 Display system 22 Operation surface 23 Display 25 Digitizer panel 50 Built-in system 100 Stylus pen 200 Stylus pen management system

Claims (20)

In order to assist the user in managing the DC power source in a portable electronic device equipped with a display system that can be operated with a stylus pen including the DC power source,
Periodically receiving the remaining capacity of the DC power source from the stylus pen;
Measuring the elapsed time since receiving the remaining capacity;
And displaying a message indicating the loss of the stylus pen on the display system when the remaining capacity is equal to or greater than a first threshold and the elapsed time exceeds a predetermined value. Computer program.   The computer program according to claim 1, wherein the display system includes an electromagnetic induction type digitizer panel, and the remaining capacity is received through a communication path formed by the digitizer panel and the stylus pen.   The computer program product of claim 1, wherein the message includes guidance indicating how to purchase the stylus pen.   The computer program product according to claim 1, further comprising: displaying a message indicating an increase in the remaining capacity on the display system when the remaining capacity reaches a second threshold value that is less than the first threshold value.   The computer program according to claim 4, wherein the message includes guidance indicating how to purchase the DC power source.   Displaying a message prompting the display system to increase the remaining capacity when the remaining capacity reaches less than a third threshold which is less than the second threshold and the elapsed time exceeds a predetermined value; The computer program according to claim 4.   The computer program according to claim 6, further comprising a step of displaying a message prompting an increase in the remaining capacity when the stylus pen is not used.   Displaying a message indicating that the increase in the remaining capacity is successful on the display system when the remaining capacity becomes equal to or greater than the first threshold after displaying the message for urging the increase in the remaining capacity. The computer program according to claim 6.   The step of receiving the remaining capacity includes receiving a packet including the remaining capacity and an identifier of the stylus pen, and measuring the elapsed time and comparing the remaining capacity and a threshold value for each identifier. A computer program described in 1. Displaying an object for checking the state of the remaining capacity on the display system;
The computer program according to claim 1, further comprising: displaying a message indicating a state relating to the remaining capacity on the display system in response to a touch operation on the object.   The computer program according to claim 1, wherein the DC power source is a non-rechargeable battery.   The computer program according to claim 1, wherein the DC power source is a rechargeable battery.   The computer program according to claim 1, wherein the DC power source is an electric double layer capacitor. To assist the user in managing the DC power source in a portable electronic device equipped with a display system that can be operated with a stylus pen equipped with a DC power source.
Periodically receiving the remaining capacity of the DC power source from the stylus pen;
Measuring the time elapsed since the last remaining capacity was received;
Displaying the message prompting the increase of the remaining capacity on the display system when the remaining capacity reaches less than a predetermined threshold and the elapsed time exceeds a predetermined value. Computer program.   The portable electronic device carrying the recording medium which memorize | stored the computer program in any one of Claims 1-14. A portable electronic device equipped with a display system that can be operated with a stylus pen equipped with a DC power source is a method for assisting a user in managing the stylus pen,
The portable electronic device periodically receiving the remaining capacity of the DC power source from the stylus pen;
Timing the elapsed time since the portable electronic device was last used on the stylus pen;
When the remaining capacity is equal to or greater than a predetermined threshold and the elapsed time exceeds a predetermined value, the portable electronic device displays a message requesting confirmation of the loss of the stylus pen on the display system; How to have.   The method of claim 16, wherein the remaining capacity is received as part of packet data including data related to operation of the stylus pen. A display system that can be operated with a stylus pen equipped with a DC power source;
A receiver that periodically receives the remaining capacity of the DC power source from the stylus pen;
A time measuring unit for measuring the elapsed time since the remaining capacity was received;
A portable electronic device having a management unit that displays a message for confirming the loss of the stylus pen on the display system when the remaining capacity is equal to or greater than a predetermined threshold and the elapsed time exceeds a predetermined value. .   19. The portable electronic device according to claim 18, wherein the display system includes an electromagnetic induction type digitizer panel, and the receiving unit receives the remaining capacity through the digitizer panel. A display system that can be operated with a stylus pen equipped with a DC power source;
A receiver that periodically receives the remaining capacity of the DC power source from the stylus pen;
A time measuring unit for measuring the elapsed time since the remaining capacity was received;
A portable electronic device comprising: a management unit that displays a message prompting an increase in the remaining capacity on the display system when the remaining capacity is less than a predetermined threshold and the elapsed time exceeds a predetermined value.

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