TECHNICAL FIELD 
       [0001]    The present invention relates to a server apparatus, information equipment, a receptacle, an electric charging information generation method and an electric charging information generation program in an electric charging system having a register that receives input of a purchase amount of a product or service, the receptacle that charges up connected information equipment and the server apparatus that determines an electric charging period or an electric charge amount of the information equipment. 
       BACKGROUND ART 
       [0002]    In recent years, performance of information equipment has dramatically improved. As the power consumption of information equipment increases, it becomes more often that the information equipment needs to be charged up at places other than home. However, it is prohibited to charge up information equipment using a receptacle provided at a building in the town without permission. In order to avoid a battery of the information equipment from running out while on the go, it is necessary to always carry around a spare battery. 
         [0003]    Various proposals have been made to eliminate such inconvenience. For example, Patent Literature (hereinafter, referred to as “PTL”) 1 discloses an electric charging terminal that bills a mobile terminal apparatus, which is registered in advance, when the registered mobile terminal apparatus is charged up. 
         [0004]    Further, PTL 2 discloses a billing server which bills a user who charges up a mobile terminal from a receptacle for commercial use according to an amount of consumed power and pays an amount corresponding to the amount of consumed power to an account of an owner of the receptacle for commercial use providing power. 
         [0005]    Further, PTL 3 discloses a receptacle billing apparatus which collects fee corresponding to the amount of consumed power from cash fed from a cash feeding port. Still further, PTL 4 discloses a mobile phone electric charging system which specifies a user of a mobile phone by exchanging information with the mobile phone and bills a user of the mobile phone for electric charging of the mobile phone. 
       CITATION LIST 
     Patent Literature 
     PTL 1 
     Japanese Patent No. 2984617 
     PTL 2 
     Japanese Patent Application Laid-Open No. 2010-250565 
     PTL 3 
     Japanese Patent Application Laid-Open No. 2010-250507 
     PTL 4 
     Japanese Patent No. 4284883 
     SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    However, while the above-described related art enables stores such as restaurants to draw customers who want to charge up their information equipment, the related art does not directly contribute to increase of sales per customer. 
         [0007]    In other words, because the above-described related art is not to encourage customers gathering in the store to purchase products or service, and a billed amount on a person who charges up his information equipment is not significant either, the related art does not substantially increase sales per customer. 
         [0008]    An object of the present invention is to provide a server apparatus, information equipment, a receptacle, an electric charging information generation method and an electric charging information generation program capable of not only drawing more customers to a store but also increasing sales per customer. 
       Solution to Problem 
       [0009]    A server apparatus according to the present invention is a server apparatus in an electric charging system including: a register that receives input of a purchase amount of a product or service; and a receptacle that charges up connected information equipment, the server apparatus including: a storage section that stores an electric charging parameter corresponding to the purchase amount; a receiving section that receives information of the purchase amount input to the register; and a generating section that searches for an electric charging parameter corresponding to the purchase amount received at the receiving section from the electric charging parameters stored in the storage section and that generates electric charging information indicating an electric charging period or an electric charge amount, the electric charging period being a period during which the receptacle performs electric charging based on the electric charging parameter, and the electric charge amount being an amount of electric charging performed by the receptacle based on the electric charging parameter. 
         [0010]    Information equipment according to the present invention is information equipment in an electric charging system including: a register that receives input of a purchase amount of a product or service; a receptacle that performs electric charging; and a server apparatus that receives the information of the purchase amount, that searches for an electric charging parameter corresponding to the purchase amount from electric charging parameters corresponding to the purchase amount and that generates electric charging information indicating an electric charging period or an electric charge amount, the electric charging period being a period during which the receptacle performs electric charging based on the electric charging parameter, and the electric charge amount being an amount of electric charging performed by the receptacle based on the electric charging parameter, the information equipment including: a storage section that stores identification information for identifying the information equipment; a receiving section that receives information of the purchase amount from the register and that receives the electric charging information from the server apparatus; and a transmitting section that transmits the identification information and the information of the purchase amount to the server apparatus and that transmits the electric charging information to the receptacle. 
         [0011]    Information equipment according to the present invention is information equipment in an electric charging system including: a register that receives input of a purchase amount of a product or service; a receptacle that performs electric charging and transmitting information of the purchase amount, and a server apparatus that receives the information of the purchase amount, that searches for an electric charging parameter corresponding to the purchase amount from electric charging parameters corresponding to the purchase amount and that generates electric charging information indicating an electric charging period or an electric charge amount, the electric charging period being a period during which the receptacle performs electric charging based on the electric charging parameter, and the electric charge amount being an amount of electric charging performed by the receptacle based on the electric charging parameter, the information equipment including: a storage section that stores identification information for identifying the information equipment; a receiving section that receives the information of the purchase amount from the register; and a transmitting section that transmits the identification information and the information of the purchase amount to the receptacle. 
         [0012]    A receptacle according to the present invention is a receptacle for electric charging in an electric charging system including: a register that receives input of a purchase amount of a product or service; information equipment that receives information of the purchase amount from the register and that forwards the information of the purchase amount; and a server apparatus that receives the information of the purchase amount, that searches for an electric charging parameter corresponding to the purchase amount from electric charging parameters corresponding to the purchase amount, and that generates electric charging information indicating an electric charging period or an electric charge amount, the electric charging period being a period during which electric charging is performed based on the electric charging parameter, and the electric charge amount being an amount of electric charging performed based on the electric charging parameter, the receptacle including: a receiving section that receives the electric charging information from the information equipment; and an electric charging section that charges up the information equipment for the electric charging period or by the electric charge amount based on the electric charging information. 
         [0013]    A receptacle according to the present invention is a receptacle for electric charging in an electric charging system including: a register that receives input of a purchase amount of a product or service; information equipment that receives information of the purchase amount from the register; and a server apparatus that receives the information of the purchase amount, that searches for an electric charging parameter corresponding to the purchase amount from electric charging parameters corresponding to the purchase amount and that generates electric charging information indicating an electric charging period or an electric charge amount, the electric charging period being a period during which electric charging is performed based on the electric charging parameter, and the electric charge amount being an amount of electric charging performed based on the electric charging parameter, the receptacle including: a receiving section that receives identification information for identifying the information equipment and the information of the purchase amount from the information equipment and that receives the electric charging information from the server apparatus; a transmitting section that transmits the identification information and the information of the purchase amount to the server apparatus; and an electric charging section that charges up the information equipment for the electric charging period or by the electric charge amount based on the electric charging information. 
         [0014]    An electric charging information generation method according to the present invention is an electric charging information generation method performed by a server apparatus in an electric charging system including: a register that receives input of a purchase amount of a product or service; and a receptacle that charges up connected information equipment, the electric charging information generation method including: receiving information of the purchase amount input to the register; and searching for an electric charging parameter corresponding to the purchase amount received in the receiving, from electric charging parameters corresponding to the purchase amount stored in advance in a storage section and generating electric charging information indicating an electric charging period or an electric charge amount, the electric charging period being a period during which the receptacle performs electric charging based on the electric charging parameter, and the electric charge amount being an amount of electric charging performed by the receptacle based on the electric charging parameter. 
         [0015]    An electric charging information generation program according to the present invention is causing an electric charging information generation program computer in an electric charging system including: a register that receives input of a purchase amount of a product or service; and a receptacle that charges up connected information equipment to execute processing including: receiving information of the purchase amount input to the register; and searching for an electric charging parameter corresponding to the purchase amount from electric charging parameters corresponding to the purchase amount stored in advance in a storage section and generating electric charging information indicating an electric charging period or an electric charge amount, the electric charging period being a period during which the receptacle performs electric charging based on the electric charging parameter, and the electric charge amount being an amount of electric charging performed by the receptacle based on the electric charging parameter. 
       Advantageous Effects of Invention 
       [0016]    According to the present invention, it is possible not only to draw more customers to the store but also to increase sales per customer by providing incentive for purchasing a product or service to a customer. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0017]      FIGS. 1A ,  1 B and  1 C illustrate outline of an electric charging system according to the present embodiment; 
           [0018]      FIG. 2  is a block diagram illustrating an exemplary configuration of an electric charging system according to Embodiment 1 of the present invention; 
           [0019]      FIG. 3  is a block diagram illustrating an exemplary configuration of a register; 
           [0020]      FIG. 4  is a block diagram illustrating an exemplary configuration of information equipment; 
           [0021]      FIG. 5  is a block diagram illustrating an exemplary configuration of a receptacle; 
           [0022]      FIG. 6  is a block diagram illustrating an exemplary configuration of a server apparatus; 
           [0023]      FIG. 7  illustrates an example of electric charging bonus point information; 
           [0024]      FIG. 8  illustrates an example of store information; 
           [0025]      FIG. 9  illustrates an example of crowded degree adjustment information; 
           [0026]      FIG. 10  illustrates an example of user information; 
           [0027]      FIG. 11  is a sequence diagram illustrating exemplary processing procedure of electric charging processing in Embodiment 1 of the present invention; 
           [0028]      FIGS. 12A ,  12 B and  12 C illustrate billing processing when a store is crowded; 
           [0029]      FIG. 13  illustrates a relationship between change of a crowded degree and a predetermined threshold; 
           [0030]      FIG. 14  is a flowchart illustrating exemplary processing procedure of billing processing when the store is crowded; 
           [0031]      FIGS. 15A ,  15 B and  15 C illustrate electric charging extension processing by additional purchase of a product or service; 
           [0032]      FIG. 16  is a flowchart illustrating exemplary processing procedure of the electric charging extension processing by additional purchase of a product or service; 
           [0033]      FIG. 17  is a block diagram illustrating an exemplary configuration of a receptacle according to Embodiment 2; 
           [0034]      FIG. 18  is a sequence diagram illustrating exemplary processing procedure of electric charging processing in Embodiment 2 of the present invention; 
           [0035]      FIG. 19  illustrates a hardware structure of a computer which implements functions of the respective apparatuses using a program; 
           [0036]      FIG. 20  illustrates service type 1 (own data center type); 
           [0037]      FIG. 21  illustrates service type 2 (IaaS-based type); 
           [0038]      FIG. 22  illustrates service type 3 (PaaS-based type); and 
           [0039]      FIG. 23  illustrates service type 4 (SaaS-based type). 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0040]    Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 
         [0041]    (Whole Picture of Service to be Provided) 
         [0042]      FIGS. 1A ,  1 B and  1 C illustrate outline of an electric charging system according to the present embodiment.  FIG. 1A  illustrates the whole picture of the electric charging system according to the present embodiment. Group  10  is, for example, a store, or the like, including various sizes of stores. Group  10  includes equipment A and equipment B which are a plurality of equipment  10   a , and gateway  10   b.    
         [0043]    The plurality of pieces of equipment  10   a  include equipment which can be connected to the Internet (for example, a smartphone, a PC, a POS (Point of Sale System) register, a smart plug, or the like), and equipment which cannot be connected to the Internet by itself. The plurality of pieces of equipment  10   a  also include equipment which can be connected to the Internet via gateway  10   b  although the equipment cannot be connected to the Internet by itself. Group  10  further includes user  1  who uses the plurality of pieces of equipment  10   a.    
         [0044]    Data center operating company  11  includes cloud server  11   a . Cloud server  11   a  is a virtual server which collaborates with various pieces of equipment via the Internet, and mainly manages huge data (big data) which is difficult to be dealt with by a typical database management tool, or the like. Data center operating company  11  manages data, manages cloud server  11   a  or operates a data center which manages data and cloud server  11   a . The operation performed by data center operating company  11  will be described in detail later. 
         [0045]    Here, data center operating company  11  is not limited to a company that only manages data and operates cloud server  11   a . For example, when an equipment manufacturer which develops and manufactures one equipment among the plurality of pieces of equipment  10   a  also manages data and cloud server  11   a , the equipment manufacturer corresponds to data center operating company  11  ( FIG. 1B ). 
         [0046]    Further, data center operating company  11  is not limited to a single company. For example, when an equipment manufacturer manages data and operates cloud server  11   a  together with other management company, or the equipment manufacturer and the other management company share management and operation, both or any one of them corresponds to data center operating company  11  ( FIG. 1C ). 
         [0047]    Service provider  12  has server  12   a . Server  12   a  described here includes, for example, any size of a memory inside a PC for personal use. Further, there is a case where the service provider does not have server  12   a.    
         [0048]    It should be noted that in the above-described service, gateway  10   b  is not essential. For example, when cloud server  11   a  manages all data, gateway  10   b  is not necessary. Further, gateway  10   b  is also not necessary when there is no equipment which cannot be connected to the Internet by itself, for example, when all the equipment in the store is connected to the Internet. 
         [0049]    The flow of information in the above-described service will now be described. First, equipment A or equipment B of group  10  transmits log information to cloud server  11   a  of data center operating company  11 . Cloud server  11   a  accumulates log information of equipment A or equipment B ((a) in  FIG. 1A ). 
         [0050]    Here, the log information refers to, for example, information indicating operation states, operation time and date, or the like, of the plurality of equipment  10   a . For example, the log information refers to information indicating operation states, operation time and date, or the like, of a smartphone, a PC, a POS register, a smart plug, or the like, but the log information is not limited to these, and refers to all the information which can be acquired from any equipment. 
         [0051]    There is a case where the log information is directly provided to cloud server  11   a  from the plurality of pieces of equipment  10   a  themselves via the Internet. Further, the log information may be accumulated in gateway  10   b  once from the plurality of pieces of equipment  10   a  and may be provided to cloud server  11   a  from gateway  10   b.    
         [0052]    Subsequently, cloud server  11   a  of data center operating company  11  provides the accumulated log information to service provider  12  in a predetermined unit. Here, this unit may be a unit in which the data center operating company can organize the accumulated information and provide the information to service provider  12  or a unit requested by service provider  12 . The unit, although described as a “predetermined unit,” does not have to be fixed, and the amount of information to be provided may change depending on the situation. 
         [0053]    The log information is stored in server  12   a  of service provider  12  as appropriate ((b) in  FIG. 1A ). Service provider  12  organizes the log information so as to be compatible with service to be provided to the user and provides the information to the user. The user to which the information is provided may be user  1  who uses the plurality of pieces of equipment  10   a  or outside user  2 . 
         [0054]    The information may be provided to the user, for example, directly from service provider  12  ((f), (e) in  FIG. 1A ). Further, the information may be provided to the user, for example, via cloud server  11   a  of data center operating company  11  again ((c), (d) in  FIG. 1A ). Further, cloud server  11   a  of data center operating company  11  may organize the log information so as to be compatible with service to be provided to the user and may provide the information to service provider  12 . 
         [0055]    It should be noted that user  1  may be different from user  2 , or user  1  and user  2  may be the same person. 
       Embodiment 1 
       [0056]      FIG. 2  is a block diagram illustrating an exemplary configuration of an electric charging system according to Embodiment 1 of the present invention. As illustrated in  FIG. 2 , in this electric charging system, register  20 , information equipment  30 , receptacle  40 , server apparatus  50  and base station apparatus  60  are connected via network  70 . Register  20 , information equipment  30  and receptacle  40  correspond to the above-described plurality of pieces of equipment  10   a , while server apparatus  50  corresponds to the above-described cloud server  11   a  or server  12   a.    
         [0057]    Register  20  is a POS register which records an amount of a product or service purchased by a customer. Information equipment  30  is equipment such as a smartphone, a mobile phone and a personal computer, which performs information processing. 
         [0058]    Receptacle  40  is equipment which supplies power to equipment such as information equipment  30 , which operates using power. Server apparatus  50  is an apparatus which manages an electric charging period when information equipment  30  is charged up from receptacle  40 . Base station apparatus  60  is an apparatus which performs radio communication with information equipment  30  and connects information equipment  30  to network  70 . Each apparatus will be described in detail later. 
         [0059]    Here, network  70  may be a wired network or a wireless network. Further, a wired network and a wireless network may exist in a mixed manner in network  70 . Hereinafter, the description will be provided assuming that network  70  is a wired network. Further, while one or more registers  20 , one or more information equipment  30 , one or more receptacles  40 , one or more server apparatuses  50  and one or more base station apparatuses  60  may be provided,  FIG. 2  illustrates one register  20 , one information equipment  30 , one receptacle  40 , one server apparatus  50  and one base station apparatus  60  to simplify the illustration. 
         [0060]      FIG. 3  is a block diagram illustrating an exemplary configuration of register  20 . Register  20  includes input section  21 , display section  22 , wired communication section  23 , radio communication section  24 , storage section  25  and control section  26 . 
         [0061]    Input section  21  is an input device such as an input key. Display section  22  is a display device such as a liquid crystal display. Wired communication section  23  is a processing section which communicates with other apparatuses via network  70 . Radio communication section  24  is a processing section which performs near-field radio communication with information equipment  30 , or the like. 
         [0062]    Storage section  25  is a storage device such as a memory and a hard disc apparatus. Storage section  25  stores purchase amount information  25   a , or the like. Purchase amount information  25   a  is information of a purchase amount when the user purchases a product or service. This purchase amount information  25   a  also includes a store ID for identifying a store where the user purchases the product or the service, information of time, or the like. 
         [0063]    This purchase amount information  25   a  is transmitted to information equipment  30  and forwarded to server apparatus  50  by information equipment  30 . Control section  26  is a control device such as a processor, which controls each section of register  20 . 
         [0064]      FIG. 4  is a block diagram illustrating an exemplary configuration of information equipment  30 . Information equipment  30  includes input section  31 , display section  32 , radio communication section  33 , storage section  34  and control section  35 . 
         [0065]    Input section  31  is an input device such as a touch panel and a keyboard. Display section  32  is a display device such as a liquid crystal display. Radio communication section  33  is a processing section which performs near-field radio communication with register  20  and receptacle  40  and communicates with server apparatus  50  via base station apparatus  60 . 
         [0066]    Storage section  34  is a storage device such as a memory and a hard disc apparatus. Storage section  34  stores, user ID  34   a , purchase amount information  34   b , electric charging period information  34   c , or the like. 
         [0067]    User ID  34   a  is identification information for identifying a user of information equipment  30 . Purchase amount information  25   a  transmitted from register  20  is stored as purchase amount information  34   b . Electric charging period information  34   c  is information of a period during which information equipment  30  can be charged up at receptacle  40 . This electric charging period information  34   c  is information received from server apparatus  50 . Control section  35  is a control device such as a processor which controls each section of information equipment  30 . 
         [0068]      FIG. 5  is a block diagram illustrating an exemplary configuration of receptacle  40 . Receptacle  40  includes radio communication section  41 , storage section  42 , electric charging section  43  and control section  44 . 
         [0069]    Radio communication section  41  is a processing section which performs near-field radio communication with information equipment  30 . Storage section  42  is a storage device such as a memory. Storage section  42  stores electric charging period information  42   a . Electric charging period information  34   c  transmitted from information equipment  30  is stored as electric charging period information  42   a.    
         [0070]    Electric charging section  43  is a processing section which charges up information equipment  30 , or the like. Electric charging section  43  reads out electric charging period information  42   a  from storage section  42  and charges up information equipment  30  only for a period designated by electric charging period information  42   a . Control section  44  is a control device such as a processor, which controls each section of receptacle  40 . 
         [0071]      FIG. 6  is a block diagram illustrating an exemplary configuration of server apparatus  50 . Server apparatus  50  includes input section  51 , display section  52 , wired communication section  53 , storage section  54  and control section  55 . 
         [0072]    Input section  51  is an input device such as a keyboard. Display section  52  is a display device such as a liquid crystal display. Wired communication section  53  is a processing section which communicates with other apparatuses via network  70 . 
         [0073]    Storage section  54  is a storage device such as a memory and a hard disk apparatus. Storage section  54  stores electric charging bonus point information  54   a , store information  54   b , crowded degree adjustment information  54   c , user information  54   d , or the like. 
         [0074]    Electric charging bonus point information  54   a  is information of an electric charging bonus point (electric charging parameter) provided to a customer according to a purchase amount of a product or service. The electric charging bonus point is converted into an electric charging period, and electric charging can be performed from receptacle  40  for the electric charging period. It should be noted that while the electric charging bonus point is converted into an electric charging period, the electric charging bonus point may be converted into an electric charge amount (for example, ampere-hour). 
         [0075]      FIG. 7  illustrates an example of electric charging bonus point information  54   a . Electric charging bonus point information  54   a  includes information of day of the week, a time slot, an electric charging bonus point and a specific electric charging bonus point. 
         [0076]    As illustrated in  FIG. 7 , an electric charging bonus point per 100 yen provided to the customer who purchases a product or service varies according to day of the week and a time slot. For example, in the example of  FIG. 7 , less electric charging bonus points are provided in day of the week and time slots when the store is crowded, while more electric charging bonus points are provided in day of the week and time slots when the store is relatively not crowded. It is thereby possible to encourage the customer to visit the store when the store is not crowded. 
         [0077]    Further, the specific electric charging bonus point is an electric charging bonus point provided to the customer who purchases a specific product or service. In the example of  FIG. 7 , twice as many points as normal electric charging bonus points are provided as the specific electric charging bonus point. Because the customer can get twice as many points as normal by purchasing a specific product or service, it is possible to encourage the customer to purchase the specific product or service. 
         [0078]    Further, store information  54   b  illustrated in  FIG. 6  is information relating to a store to be utilized by the customer.  FIG. 8  illustrates an example of store information  54   b . Store information  54   b  includes information of a store ID, the total number of receptacles, the number of receptacles being used, a crowded degree, a lowest electricity expense time slot and location information. 
         [0079]    The store ID is identification information for identifying a store. The total number of receptacles is the total number of receptacles which can be utilized to charge up information equipment  30 . The number of receptacles being used is the number of receptacles which are being used to charge up information equipment  30  at that time. 
         [0080]    The crowded degree is information indicating a crowded degree of the store. The crowded degree is a ratio of the number of receptacles being used with respect to the total number of receptacles. It should be noted that while the crowded degree is determined in this manner here, the crowded degree is not limited to this. For example, when there are seats equipped with receptacles and seats not equipped with receptacles in the store, the crowded degree may be an occupancy ratio of the seats equipped with receptacles. 
         [0081]    For example, it is also possible to shoot inside of the store with a camera and determine the crowded degree of the store by detecting the number of people by way of image analysis, or it is also possible to determine the crowded degree of the store by the number of times purchase information of a customer is input to register  20  in a given period of time. Further, it is also possible to determine the crowded degree of the store from the number of times an entrance door opens in a given period of time. 
         [0082]    The lowest electricity expense time slot is information of a time slot during which electricity expense is the lowest. Because in this time slot, an electric charging bonus point is converted into a longer electric charging period than that in other time slots, it is possible to make electric charging bonus points less consumed when electric charging is performed in this time slot. 
         [0083]    The location information is information of location of the store. This location information is, for example, comprised of a combination of the latitude and the longitude. In the example of  FIG. 8 , information of the latitude of “35.65 . . . ” and the longitude of “139.74 . . . ” is registered as location information of the store having a store ID of “1001.” This location information is used when the customer searches for the nearest store. 
         [0084]    Further, crowded degree adjustment information  54   c  illustrated in  FIG. 6  is information used for adjusting an electric charging bonus point to be provided to the customer according to the crowded degree of the store.  FIG. 9  illustrates an example of crowded degree adjustment information  54   c . Crowded degree adjustment information  54   c  includes a crowded degree and information of magnification. 
         [0085]    The crowded degree is the same information as the crowded degree in store information  54   b  illustrated in  FIG. 8 . The magnification is information of a numerical value by which an electric charging bonus point is multiplied according to the crowded degree of the store. For example, in the example of electric charging bonus point information  54   a  illustrated in  FIG. 7 , an electric charging bonus point on “Sunday” and in a time slot of “10:00-14:00” is “100” per 100 yen. 
         [0086]    Therefore, when the customer visits the store at 11:00 am on Sunday and purchases a product which is not a specific product at 1,000 yen, an electric charging bonus point to be provided to the customer is 1,000 points. This electric charging bonus point is adjusted based on crowded degree adjustment information  54   c  illustrated in  FIG. 9 . 
         [0087]    Specifically, when the crowded degree is “lower than 25%,” the electric charging bonus point to be provided is doubled, and 2,000 points are provided to the customer. Further, when the crowded degree is “25% or higher and less than 50%”, the electric charging bonus point to be provided is multiplied by 1.5, and 1,500 points are provided to the customer. When the crowded degree is “50% or higher and lower than 75%,” 1,000 points are provided to the customer. Further, when the crowded degree is “75% or higher,” the electric charging bonus point to be provided is multiplied by 0.5, and 500 points are provided to the customer. 
         [0088]    In this example, more electric charging bonus points are provided to the customer when the store is not crowded, while less electric charging bonus points are provided to the customer when the store is crowded. It is therefore possible to encourage the customer to visit the store when the store is not crowded. 
         [0089]    User information  54   d  illustrated in  FIG. 6  is information of the customer who utilizes the electric charging system.  FIG. 10  illustrates an example of user information  54   d . User information  54   d  includes information of a user ID, an accumulated electric charging bonus point, a membership flag, a possessed product, a last visit store ID, a spending period and an electric charging flag. 
         [0090]    The user ID is the same information as user ID  34   a  described with reference to  FIG. 4 . The accumulated electric charging bonus point is a value obtained by subtracting a value corresponding to points used by the customer to charge up information equipment  30  from an accumulation value of an electric charging bonus point provided to the customer until then every time the customer purchases a product or service. For example, when the accumulation value of the point provided to the customer until then is 300, if the customer charges up information equipment  30  for 15 minutes, the electric charging bonus point decreases by 100 points and the accumulated electric charging bonus point becomes 200. 
         [0091]    The membership flag is a flag indicating whether or not the customer is a member of a predetermined club. The predetermined club is, for example, a fan club of a product of the company. If the customer is a member of the predetermined club, a conversion ratio between the electric charging bonus point and the electric charging period is changed. 
         [0092]    For example, while the customer who is not a member of the predetermined club can be allowed for electric charging for 15 minutes with 100 points, if he is a member of the predetermined club, the conversion ratio is changed so that the customer can be allowed for electric charging for 20 minutes with 100 points. Alternatively, it is also possible to add extra predetermined points (for example, 50 points) to the electric charging bonus point provided to the customer who is a member of the predetermined club. By this means, it is possible to encourage the customer to register as a member of the predetermined club. 
         [0093]    The possessed product is information of a product possessed by the customer. This product is, for example, a product of the company relating to the above-described fan club. For example, the customer can register the possessed product through the website on the Internet. The information registered through the website is also registered in user information  54   d.    
         [0094]    The information of the possessed product is used when the electric charging bonus point is provided to the customer. Specifically, the conversion ratio between the electric charging bonus point and the electric charging period is changed according to the number of possessed products. 
         [0095]    For example, while the customer who does not possess any product can be allowed for electric charging for 15 minutes with 100 points, if the number of possessed products is A (A is an integer of one or more), the conversion ratio is changed so that the customer can be allowed for electric charging for (15+5×A) minutes with 100 points. 
         [0096]    Alternatively, it is also possible to add extra predetermined points (for example, 50 points) per product to the electric charging bonus point provided to the customer. By this means, it is possible to encourage the customer to purchase products. 
         [0097]    It is also possible to further take into account information of a usage state of the possessed product. For example, it is also possible to make server apparatus  50  collect information of frequency of usage of a product connected to a network in a given period of time, and change the conversion ratio between the electric charging bonus point and the electric charging period if the frequency of usage exceeds a predetermined threshold. 
         [0098]    For example, while the customer can be allowed for electric charging for 15 minutes with 100 points if the frequency of usage does not exceed the predetermined threshold, the conversion ratio is changed so that the customer can be allowed for electric charging for 20 minutes with 100 points if the frequency of usage exceeds the predetermined threshold. Alternatively, it is also possible to add extra predetermined points (for example, 50 points) to the electric charging bonus point provided to the customer if the frequency of usage exceeds the predetermined threshold. It is thereby possible to encourage the customer to use the product. 
         [0099]    Returning to  FIG. 10 , the last visit store ID is information indicating a store ID of a store where the customer charges up information equipment  30  last time. When the customer purchases a product or service at the store, the information of the store ID of the store where the customer purchases the product or service is transmitted from information equipment  30  to server apparatus  50  along with information of the purchase amount. The store ID received last time from information equipment  30  is registered as the last visit store ID. 
         [0100]    This last visit store ID is used to specify the store when the customer left information equipment  30  at the store. Specifically, if the customer accesses a predetermined website using a personal computer, or the like, information such as address and phone number of the store corresponding to the last visit store ID is displayed. By this means, the customer can easily specify the place where he left information equipment  30 . 
         [0101]    The spending period is information of a period the customer will stay at the store. Information of the starting point of the spending period (for example, “21:04” when the spending period is “21:04-23:00”) is information of time transmitted from information equipment  30  to server apparatus  50  when the customer purchases a product or service. If the customer does not purchase a product or service, the information of the spending period is not registered. 
         [0102]    Information of the end point of the spending period (for example, “23:00” when the spending period is “21:04-23:00”) is input by the customer using information equipment  30  and transmitted to server apparatus  50 . Here, if there is no input by the customer, the information of the end point of the spending period is not registered (for example, as illustrated in  FIG. 10 , only the information of the starting point is registered as “20:48-”). 
         [0103]    The information of the spending period is utilized so that electric charging is performed in a time slot in which electricity expense is the lowest. For example, when the customer inputs the information of the end point of the spending period, information of a lowest electricity expense time slot at the store where the customer stays is searched from store information  54   b  illustrated in  FIG. 8 . Then, it is determined whether the spending period of the customer overlaps with the lowest electricity expense time slot of the store, and if the spending period overlaps with the lowest electricity expense time slot, the electric charging period is set so that electric charging can be performed in a time slot in which the spending period overlaps with the lowest electricity expense time slot. 
         [0104]    For example, when the spending period of the customer is “21:04-23:00” and the lowest electricity expense time slot of the store is “22:00-7:00,” because the spending period overlaps with the lowest electricity expense time slot during “22:00-23:00,” the electric charging period is set so that electric charging is performed in this time slot. 
         [0105]    Returning to  FIG. 10 , the electric charging flag is a flag indicating whether or not information equipment  30  is charged up at that time. By collecting the number of information equipment  30  being charged up for each store using information of this electric charging flag, it is possible to calculate the number of receptacles being used in each store in store information  54   b  illustrated in  FIG. 8 . 
         [0106]    Returning to  FIG. 6 , control section  55  is a control device such as a processor, which controls each section of server apparatus  50 . Control section  55  includes generating section  55   a , store information output section  55   b , assigning section  55   c  and issuing section  55   d.    
         [0107]    Generating section  55   a  is a processing section which generates electric charging information indicating an electric charging period during which a receptacle performs electric charging. Specifically, generating section  55   a  acquires the purchase amount information and the information of the user ID transmitted from information equipment  30 . Generating section  55   a  then reads out an electric charging bonus point corresponding to day of the week and the time slot from electric charging bonus point information  54   a  illustrated as an example in  FIG. 7 . 
         [0108]    It should be noted that to encourage the customer to purchase a specific product or specific service, generating section  55   a  further acquires specific product and service information transmitted from information equipment  30 . This specific product and service information is information indicating whether or not the customer has purchased a specific product or service. In this case, generating section  55   a  reads out a specific electric charging bonus point corresponding to day of the week and the time slot from electric charging bonus point information  54   a  illustrated as an example in  FIG. 7 . 
         [0109]    Further, generating section  55   a  adjusts an electric charging bonus point to be provided to the customer according to a crowded degree of the store. Specifically, generating section  55   a  generates information of the crowded degree in store information  54   b  illustrated as an example in  FIG. 8 . Generating section  55   a  then reads out information of magnification according to the crowded degree from crowded degree adjustment information  54   c  illustrated as an example in  FIG. 9 . 
         [0110]    Subsequently, generating section  55   a  multiplies the electric charging bonus point read from electric charging bonus point information  54   a  illustrated as an example in  FIG. 7  by the magnification. Generating section  55   a  adds the electric charging bonus point obtained in this manner to the accumulated electric charging bonus point of electric charging bonus point information  54   a  illustrated as an example in  FIG. 10 . Generating section  55   a  then updates the information of the accumulated electric charging bonus point of electric charging bonus point information  54   a  with the accumulated electric charging bonus point obtained as a result of the addition. 
         [0111]    Further, generating section  55   a  converts the accumulated electric charging bonus point into an electric charging period using a predefined conversion ratio between the accumulated electric charging bonus point and the electric charging period. For example, generating section  55   a  converts the accumulated electric charging bonus point of 100 into the electric charging period of 15 minutes. 
         [0112]    At that time, generating section  55   a  determines whether or not the customer is a member of a predetermined club with reference to the membership flag information of user information  54   d  illustrated as an example in  FIG. 10 . If the customer is a member of the predetermined club, generating section  55   a  changes the above conversion ratio and converts the accumulated electric charging bonus point into the electric charging period using the changed conversion ratio. For example, generating section  55   a  converts the accumulated electric charging bonus point of 100 into the electric charging period of 20 minutes. 
         [0113]    Further, generating section  55   a  determines whether or not the customer possesses a product of a predetermined company, or the like, with reference to information of the possessed product of user information  54   d  illustrated as an example in  FIG. 10 . If the customer possesses the product, generating section  55   a  changes the above conversion ratio according to the number of products and converts the accumulated electric charging bonus point into the electric charging period using the changed conversion ratio. 
         [0114]    For example, when the number of possessed products is A (A is an integer of one or more), generating section  55   a  changes the conversion ratio so as to allow electric charging for (15+5×A) minutes with the accumulated electric charging bonus point of 100. 
         [0115]    Further, the server apparatus may collect information of frequency of usage of a product for a certain period, and if the frequency of usage exceeds a predetermined threshold, generating section  55   a  may change the conversion ratio between the accumulated electric charging bonus point and the electric charging period. For example, if the frequency of usage exceeds the predetermined threshold, generating section  55   a  changes the conversion ratio so as to allow electric charging for 20 minutes with the accumulated electric charging bonus point of 100. 
         [0116]    Generating section  55   a  converts the accumulated electric charging bonus point into the electric charging period using the conversion ratio changed as described above. 
         [0117]    Further, when the customer inputs information of the spending period during which he will stay at the store using information equipment  30 , generating section  55   a  searches for information of the lowest electricity expense time slot of the store where the customer stays from store information  54   b  illustrated as an example in  FIG. 8 . 
         [0118]    Generating section  55   a  then determines whether or not the spending period of the customer overlaps with the lowest electricity expense time slot of the store, and, if the spending period overlaps with the lowest electricity expense time slot, sets the electric charging period so that electric charging can be performed in a time slot during which the spending period overlaps with the lowest expense time slot. 
         [0119]    For example, if the spending period of the customer is “21:04-23:00” and the lowest electricity expense time slot of the store is “22:00-7:00,” generating section  55   a  sets the electric charging period so that electric charging is performed in a time slot of “22:00-23:00.” 
         [0120]    After the above-described processing, generating section  55   a  generates electric charging information indicating the electric charging period. It should be noted that if the spending period of the customer overlaps with the lowest electricity expense time slot of the store, the electric charging information includes information of the time slot which is set so that electric charging is performed in the lowest electricity expense time slot. This electric charging information is used by receptacle  40  to control the electric charging period of information equipment  30 . 
         [0121]    Further, while the electric charging period is provided to the customer according to the accumulated electric charging bonus point, it is also possible to provide a predetermined electric charging period to the customer for free regardless of the accumulated electric charging bonus point. By this means, it is possible for the store to draw more customers. 
         [0122]    However, if the crowded degree of the store becomes equal to or greater than a predetermined threshold, it is also possible to make generating section  55   a  shorten a free electric charging period. By this means, it is possible to provide electric charging service to more customers. 
         [0123]    Further, generating section  55   a  determines whether or not the accumulated electric charging bonus point registered in user information  54   d  illustrated as an example in  FIG. 10  is equal to or less than a predetermined value. If the accumulated electric charging bonus point becomes equal to or less than the predetermined value, generating section  55   a  generates information for recommending that the customer purchase a product or service and encouraging the customer to get the accumulated electric charging bonus point. This information is transmitted to information equipment  30  by wired communication section  53  and displayed on information equipment  30 . By this means, it is possible to prevent situation where electric charging becomes suddenly impossible. 
         [0124]    Store information output section  55   b  is a processing section which outputs information of a last visit store ID for specifying a store where the customer has purchased a product or service last time. This information is transmitted to a web server apparatus which provides a predetermined website, by wired communication section  53 . When the customer accesses this website using a personal computer, or the like, information such as address and phone number of the store is displayed. 
         [0125]    Assigning section  55   c  is a processing section which assigns an electric charging period to a person different from the customer who has purchased a product or service. Specifically, when wired communication section  53  receives a command for providing an electric charging bonus point from information equipment  30  of the customer who has purchased a product or service to another person, assigning section  55   c  assigns a point designated by the customer among the accumulated electric charging bonus point of user information  54   d  illustrated as an example in  FIG. 10  to another user. 
         [0126]    By assigning an electric charging bonus point to another user in this manner, it is possible to induce another user to visit the store or encourage another user to be a member of a fan club of a product of the company. 
         [0127]    Issuing section  55   d  is a processing section which searches for a store whose crowded degree is equal to or lower than a predetermined level within certain distance from the designated store and issues a coupon which can be used at the store whose crowded degree is equal to or lower than the predetermined level. 
         [0128]    For example, when the customer designates a certain store in a predetermined website, issuing section  55   d  receives information of a store ID of the designated store from a web server apparatus which provides the website via wired communication section  53 . 
         [0129]    Issuing section  55   d  then searches for a store whose crowded degree is equal to or less than the predetermined value within certain distance from the designated store with reference to the information of the crowded degree and the location information of store information  54   b  illustrated as an example in  FIG. 8 . 
         [0130]    Subsequently, issuing section  55   d  transmits information of the store ID of the searched store to the web server apparatus which provides the above-described website via wired communication section  53 . The web server apparatus which receives this information displays the information of the store on the website. By this means, the user can easily know a nearby store which is not crowded. 
         [0131]    Further, issuing section  55   d  transmits information of a coupon which can be utilized at the store to information equipment  30  of the customer via wired communication section  53 . This coupon provides some kind of specific benefits to the customer. For example, this coupon provides free electric charging service for 15 minutes to the user. 
         [0132]    For example, when the customer presents the information of this coupon to a store clerk at the searched store, the store clerk operates register  20  to embed the information in purchase amount information  25   a  illustrated in  FIG. 3  to be transmitted to server apparatus  50 . Here, the information of the coupon is, for example, information indicating that free electric charging service for 15 minutes is provided to the customer. Purchase amount information  25   a  is transmitted to server apparatus  50  via information equipment  30 . 
         [0133]    It should be noted that while the store clerk embeds the information of the coupon in purchase amount information  25   a  here, if radio communication section  33  of information equipment  30  receives purchase amount information  25   a  from register  20 , control section  35  of information equipment  30  may embed the information of the coupon in purchase amount information  25   a.    
         [0134]    Generating section  55   a  of server apparatus  50  which receives this information generates electric charging information indicating an electric charging period which has been extended by 15 minutes and transmits the electric charging information to information equipment  30 . This electric charging information is forwarded from information equipment  30  to receptacle  40 , and information equipment  30  is charged up for an electric charging period included in the electric charging information. 
         [0135]    In this way, by providing a coupon to the customer as well as by providing information of a store which is not crowded to the customer, it is possible to effectively induce the customer to visit a store which is not relatively crowded instead of visiting a crowded store. 
         [0136]    It should be noted that the above-mentioned coupon may be changed, for example, according to a remaining battery level of information equipment  30 . This example (hereinafter, referred to as specific example 1) will be described. When receiving remaining battery level information from information equipment  30  via wired communication section  53 , issuing section  55   d  compares a remaining battery level of information equipment  30  indicated in the information with threshold A which is set in advance. As a result of this comparison, if the remaining battery level is greater than threshold A, issuing section  55   d  determines the information of the coupon so that electric charging service for a predefined first period (for example, 15 minutes as described above) is provided. On the other hand, as a result of the above comparison, if the remaining battery level is equal to or less than threshold A, issuing section  55   d  determines the information of the coupon so that a predefined second period (a period longer than the first period, for example, 30 minutes) is provided. In this way, issuing section  55   d  determines the information of the coupon so that electric charging service is provided for a longer period when the remaining battery level is less and determines the information of the coupon so that the electric charging service is provided for a shorter period when the remaining battery level is greater. 
         [0137]    Alternatively, the above-mentioned coupon may be changed, for example, according to distance between current location of information equipment  30  and location of the store (store searched by issuing section  55   d ). This example (hereinafter, referred to as specific example 2) will be described. When receiving current location information from information equipment  30  via wired communication section  53 , issuing section  55   d  calculates distance (hereinafter, referred to as travel distance) from the current location of information equipment  30  indicated in the information to the location of the store. Then, issuing section  55   d  compares the travel distance with threshold B which is set in advance. As a result of this comparison, if the travel distance is equal to or less than threshold B, issuing section  55   d  determines the information of the coupon so that electric charging service for a predefined first period (for example, 15 minutes as described above) is provided. On the other hand, as a result of the above comparison, if the travel distance is greater than threshold B, issuing section  55   d  determines the information of the coupon so that electric charging service for a predefined second period (period longer than the first period, for example 30 minutes) is provided. In this way, issuing section  55   d  determines the information of the coupon so that electric charging service is provided for a longer period if the travel distance is longer, and determines the information of the coupon so that electric charging service is provided for a shorter period if the travel distance is shorter. 
         [0138]    Alternatively, the above-described specific example 1 and specific example 2 may be combined. Specifically, the above-mentioned coupon may be changed according to the remaining battery level and the travel distance. This example (hereinafter, referred to as specific example 3) will be described. Issuing section  55   d  compares the remaining battery level with threshold A as described in the above specific example 1 and compares the travel distance with threshold B as described in the above specific example 2. As a result of these comparison, if the remaining battery level is equal to or less than threshold A and the travel distance is greater than threshold B, issuing section  55   d  determines that electric charging service is provided for a first period (longer than a second period which will be described later). Further, as a result of the above-described comparison, if the remaining battery level is equal to or less than threshold A and the travel distance is equal to or less than threshold B, issuing section  55   d  determines that electric charging service is provided for a second period (shorter than the first period). Further, as a result of the above-described comparison, if the remaining battery level is greater than threshold A and the travel distance is greater than threshold B, issuing section  55   d  determines that electric charging service is provided for a third period (shorter than the second period). Still further, as a result of the above-described comparison, if the remaining battery level is greater than threshold A and the travel distance is equal to or less than threshold B, issuing section  55   d  determines that electric charging service is provided for a fourth period (shorter than the third period). In this way, issuing section  55   d  determines the information of the coupon so that electric charging service is provided for the longest period when the remaining battery level is less and the travel distance is longer, and determines the information of the coupon so that electric charging service is provided for the shortest period when the remaining battery level is greater and the travel distance is shorter. 
         [0139]    It should be noted that while, in the above-described each specific example, one threshold is used for comparison of the remaining battery level, and one threshold is used for comparison of the travel distance, it is also possible to perform each comparison using two or more thresholds and determine a period for providing electric charging service according to each result of comparison. 
         [0140]    Further, while in the above-described specific examples, the remaining battery level and/or the travel distance are compared with the thresholds, it is also possible to determine a period for providing electric charging service without using thresholds. For example, issuing section  55   d  may determine the period for providing electric charging service based on the remaining battery level indicated in the remaining battery level information and an information table in which a period for providing electric charging service is defined for each remaining battery level. Further, for example, issuing section  55   d  may calculate travel distance based on the current location information and the location information of the store and may determine a period for providing electric charging service based on the travel distance and an information table in which a period for providing electric charging service is defined for each travel distance. 
         [0141]    Further, while in the above-described each specific example, a period for providing electric charging service is determined as the content of the coupon, an electric charging bonus point to be provided to the user may be determined as the content of the coupon. 
         [0142]    In this way, according to the above-described specific examples 1 to 3, by changing the information of the coupon according to at least one of the remaining battery level and the travel distance, it is possible to more effectively induce the customer to visit the store. 
         [0143]    An example of the processing procedure of the electric charging processing according to Embodiment 1 of the present invention will now be described.  FIG. 11  is a sequence diagram illustrating an example of the processing procedure of the electric charging processing according to Embodiment 1 of the present invention. 
         [0144]    Receptacle  40  provided at the store transmits usage information to server apparatus  50  (step S 101 ). The usage information is information indicating whether or not receptacle  40  is being used to charge up information equipment  30 . Server apparatus  50  then receives the usage information (step S 102 ). The number of receptacles being used of store information  54   b  illustrated as an example in  FIG. 8  is calculated from this usage information. 
         [0145]    Subsequently, server apparatus  50  determines the crowded degree of the store (step S 103 ). Specifically, server apparatus  50  determines the crowded degree from the total number of receptacles and the number of receptacles being used of store information  54   b.    
         [0146]    Meanwhile, when the customer purchases a product or service, register  20  executes billing processing (step S 104 ). For example, register  20  receives input of a product or service and an amount and receives payment with electronic money from information equipment  30 . 
         [0147]    Register  20  then transmits information of a purchase amount of the product or the service to information equipment  30  (step S 105 ). This information includes information of a store ID for identifying the store and information of time. Information equipment  30  receives this information (step S 106 ). 
         [0148]    Information equipment  30  which receives the information of the purchase amount, transmits the information of the user ID to server apparatus  50  along with the information of the purchase amount (step S 107 ). Server apparatus  50  receives the information of the purchase amount and the information of the user ID (step S 108 ). 
         [0149]    Subsequently, server apparatus  50  generates electric charging information indicating an electric charging period using the information of the crowded degree, or the like, as described above (step S 109 ). Server apparatus  50  then transmits the electric charging information to information equipment  30  (step S 110 ). 
         [0150]    Information equipment  30  receives the electric charging information transmitted from server apparatus  50  (step S 111 ) and forwards the information to receptacle  40  (step S 112 ). The receptacle  40  then receives the electric charging information (step S 113 ) and charges up information equipment  30  only for an electric charging period included in the electric charging information (step S 114 ). 
         [0151]    An example of the processing procedure of billing processing when the store is crowded will now be described.  FIGS. 12A to 12C  illustrate billing processing when the store is crowded.  FIG. 13  illustrates a relationship between change of the crowded degree and a predetermined threshold. 
         [0152]    It is assumed that, in this electric charging service, for example, electric charging is allowed for 15 minutes for free regardless of the accumulated electric charging bonus point. However, as illustrated in  FIG. 13 , if the crowded degree of the store exceeds a predetermined threshold, this electric charging period is shortened. 
         [0153]      FIG. 12A  illustrates an exemplary screen displayed on information equipment  30  when a free electric charging period is shortened to 5 minutes to go because the crowded degree of the store exceeds the predetermined threshold. On this screen, an “Approve Billing” button and a “Finish Electric Charging” button are displayed. If this display is shown, it is controlled that LED (Light Emitting Diode)  36   a  provided at plug  36  of information equipment  30  blinks. 
         [0154]    When the user selects the “Approve Billing” button, the electric charging period is extended, and as illustrated in  FIG. 12B , a message for notifying the customer that the electric charging period has been extended is displayed on information equipment  30 . In this case, as described above, the accumulated electric charging bonus point registered in user information  54   d  illustrated as an example in  FIG. 10  decreases according to the electric charging period. 
         [0155]    Meanwhile, when the user selects the “Finish Electric Charging” button, electric charging processing for information equipment  30  is stopped, and, as illustrated in  FIG. 12C , a message for notifying the customer that the electric charging processing is stopped is displayed on information equipment  30 . 
         [0156]      FIG. 14  is a flowchart illustrating an example of the processing procedure of billing processing when the store is crowded. This processing is performed by server apparatus  50 . 
         [0157]    First, server apparatus  50  receives the usage information from receptacle  40  (step S 201 ). Server apparatus  50  then determines the crowded degree of the store (step S 202 ). If the crowded degree is not greater than a predetermined threshold (step S 203 : NO), processing from step S 204  to step S 209  is not executed. 
         [0158]    If the crowded degree is greater than the predetermined threshold (step S 203 : YES), server apparatus  50  transmits billing information to information equipment  30  (step S 204 ). The billing information is information for notifying the customer that a free electric charging period will end and inquiring as to whether or not the customer approves billing as illustrated in  FIG. 12A . 
         [0159]    It should be noted that this billing information includes control information for making LED  36   a  provided at plug  36  of information equipment  30  blink. As a result of LED  36   a  blinking with this control information, it is possible to reliably notify the user that a free electric charging period will end. 
         [0160]    Subsequently, server apparatus  50  receives information as to whether or not the customer approves billing from information equipment  30  (step S 205 ). If the customer approves billing (step S 206 : YES), server apparatus  50  executes billing processing (step S 207 ). The billing processing is processing for converting the accumulated electric charging bonus point registered in user information  54   d  illustrated as an example in  FIG. 10  into an electric charging period at a predetermined conversion ratio. 
         [0161]    Server apparatus  50  then transmits electric charging continuation information including information of the electric charging period to information equipment  30  (step S 208 ). This electric charging continuation information is forwarded from information equipment  30  to receptacle  40 . Receptacle  40  charges up information equipment  30  only for an electric charging period included in the electric charging continuation information. 
         [0162]    If the customer does not approve billing (step S 206 : NO), server apparatus  50  transmits electric charging cancellation information including information for instructing cancellation of electric charging to information equipment  30  (step S 209 ). This electric charging cancellation information is forwarded from information equipment  30  to receptacle  40 . Receptacle  40  cancels electric charging of information equipment  30  after a predetermined period has passed. 
         [0163]    An example of the processing procedure of electric charging extension processing by additionally purchasing a product or service will now be described.  FIGS. 15A to 15C  illustrate electric charging extension processing performed when a product or service is additionally purchased. This electric charging extension processing is processing executed when the accumulated electric charging bonus point registered in user information  54   d  illustrated as an example in  FIG. 10  is equal to or less than a predetermined value. 
         [0164]      FIG. 15A  illustrates an exemplary screen displayed on information equipment  30  when the accumulated electric charging bonus point is equal to or less than the predetermined value. In this exemplary screen, it is shown that the electric charging period can be extended if a product or service is additionally purchased. If this display is shown, it is controlled that LED  36   a  provided at plug  36  of information equipment  30  blinks. 
         [0165]    If the customer additionally purchases a product or service, the electric charging period is extended, and, as illustrated in  FIG. 15B , a message for notifying the customer that the electric charging period has been extended is displayed on information equipment  30 . Meanwhile, if the customer does not additionally purchase a product or service, the electric charging period is not extended, and, as illustrated in  FIG. 15C , a message for notifying the customer of the remaining electric charging period is displayed on information equipment  30 . 
         [0166]      FIG. 16  is a flowchart illustrating an example of processing procedure of electric charging extension processing when a product or service is additionally purchased. This processing is performed by server apparatus  50 . 
         [0167]    First, server apparatus  50  searches for a customer whose accumulated electric charging bonus point is equal to or less than a predetermined value and who is performing electric charging with reference to the accumulated electric charging bonus point and information of the electric charging flag of user information  54   d  illustrated as an example in  FIG. 10  (step S 301 ). 
         [0168]    Server apparatus  50  transmits purchase recommendation information to information equipment  30  (step S 302 ). The purchase recommendation information is information displayed on information equipment  30  to recommend that the searched customer purchase a product or service and to encourage the searched customer to get the accumulated electric charging bonus point as illustrated as an example in  FIG. 15A . 
         [0169]    Further, this purchase recommendation information includes control information for making LED  36   a  provided at plug  36  of information equipment  30  blink. As a result of LED  36   a  blinking with this control information, it is possible to reliably encourage the user to get the accumulated electric charging bonus point. 
         [0170]    Server apparatus  50  then determines whether or not the customer has purchased a product or service based on information as to whether or not purchase amount information transmitted by information equipment  30  when the customer purchases a product or service is received (step S 303 ). 
         [0171]    If the customer purchases a product or service (step S 303 : YES), server apparatus  50  provides an electric charging bonus point to the customer and transmits information of the electric charging period after the electric charging period has been extended as illustrated in  FIG. 15B  to information equipment  30  (step S 304 ). This information is then displayed on information equipment  30 . 
         [0172]    Meanwhile, if the customer does not purchase a product or service (step S 303 : NO), server apparatus  50  transmits information of the remaining electric charging period as illustrated in  FIG. 15C  to information equipment  30  (step S 305 ). Then, this information is displayed on information equipment  30 . 
       Embodiment 2 
       [0173]    While in the above-described Embodiment 1, information equipment  30  transmits purchase amount information indicating an amount of a product or service purchased by the customer and information of the user ID for identifying the customer to server apparatus  50 , a receptacle having a communication function may transmit these pieces of information to server apparatus  50 . In Embodiment 2, such a case will be described. 
         [0174]      FIG. 17  is a block diagram illustrating an exemplary configuration of receptacle  80  according to Embodiment 2. Receptacle  80  is used in place of receptacle  40  illustrated in Embodiment 1. Receptacle  80  includes radio communication section  81 , wired communication section  82 , storage section  83 , electric charging section  84  and control section  85 . 
         [0175]    Radio communication section  81  is a processing section which performs near-field radio communication with information equipment  30 . Wired communication section  82  is a processing section which communicates with another apparatus such as server apparatus  50  via network  70 . 
         [0176]    Storage section  83  is a storage device such as a memory. Storage section  83  stores user ID  83   a , purchase amount information  83   b  and electric charging period information  83   c.    
         [0177]    User ID  83   a  which is received from information equipment  30 , is identification information for identifying a user of information equipment  30 . This user ID  83   a  is the same information as user ID  34   a  described using  FIG. 4 . 
         [0178]    Purchase amount information  83   b  which is also received from information equipment  30 , is information of a purchase amount when the user purchases a product or service. This purchase amount information  83   b  is the same information as purchase amount information  34   b  described using  FIG. 4 . 
         [0179]    Electric charging period information  83   c  is information of a period during which information equipment  30  can be charged up using receptacle  80 . This electric charging period information  83   c  is information received from server apparatus  50 . 
         [0180]    Electric charging section  84  is a processing section which charges up information equipment  30 , or the like. Electric charging section  84  reads out electric charging period information  83   c  from storage section  83  and charges up information equipment  30  only for a period designated by electric charging period information  83   c . Control section  85  is a control device such as a processor, which controls each section of receptacle  80 . 
         [0181]    An example of the processing procedure of electric charging processing according to Embodiment 2 of the present invention will now be described.  FIG. 18  is a sequence diagram illustrating an example of the processing procedure of electric charging processing according to Embodiment 2 of the present invention. 
         [0182]    Receptacle  80  provided at the store transmits usage information to server apparatus  50  (step S 401 ). The usage information is information indicating whether or not receptacle  80  is being used to charge up information equipment  30 . Server apparatus  50  then receives the usage information (step S 402 ). The number of receptacles being used of store information  54   b  illustrated as an example in  FIG. 8  is calculated from this usage information. 
         [0183]    Server apparatus  50  then determines the crowded degree of the store (step S 403 ). Specifically, server apparatus  50  determines the crowded degree from the total number of receptacles and the number of receptacles being used of store information  54   b.    
         [0184]    Meanwhile, when the customer purchases a product or service, register  20  executes billing processing (step S 404 ). Specifically, register  20  receives input of a product or service and an amount and receives payment with electronic money from information equipment  30 . 
         [0185]    Register  20  then transmits information of a purchase amount of the product or the service to information equipment  30  (step S 405 ). This information includes information of the store ID for identifying the store and information of time. Information equipment  30  receives this information (step S 406 ). 
         [0186]    Information equipment  30  which receives the information of the purchase amount transmits the information of the purchase amount and the information of the user ID to receptacle  80  using near-field radio communication when information equipment  30  is connected to receptacle  80  (step S 407 ). Receptacle  80  receives these pieces of information (step S 408 ). 
         [0187]    Subsequently, receptacle  80  transmits the information of the purchase amount and the information of the user ID received from information equipment  30  to server apparatus  50  (step S 409 ). Server apparatus  50  receives the information of the purchase amount and the information of the user ID (step S 410 ). 
         [0188]    Server apparatus  50  then generates electric charging information indicating an electric charging period using the information of the crowded degree, or the like, as described in Embodiment 1 (step S 411 ). Server apparatus  50  then transmits the electric charging information to receptacle  80  (step S 412 ). 
         [0189]    Receptacle  80  receives the electric charging information transmitted from server apparatus  50  (step S 413 ) and charges up information equipment  30  only for the electric charging period included in the electric charging information (step S 414 ). 
         [0190]    While the embodiments according to the present invention have been described in detail above with reference to the drawings, functions of the above-described register  20 , information equipment  30 , receptacles  40  and  80 , server apparatus  50  and base station apparatus  60  can be implemented using a computer program. 
         [0191]      FIG. 19  illustrates a hardware structure of a computer which implements the functions of the apparatuses using a program. 
         [0192]    This computer  100  includes input apparatus  101  such as a keyboard, a mouse, a touch pad and a button, output apparatus  102  such as a display and a speaker, CPU (Central Processing Unit)  103 , ROM (Read Only Memory)  104  and RAM (Random Access Memory)  105 . Computer  100  further includes storage apparatus  106  such as a hard disk apparatus and an SSD (Solid State Drive), reading apparatus  107  which reads information from a recording medium such as a DVD-ROM (Digital Versatile Disk Read Only Memory) and a USB (Universal Serial Bus) memory, and network card  108  which communicates via a network. The above-described sections are connected using bus  109 . 
         [0193]    Reading apparatus  107  then reads a program for implementing the functions of the above-described apparatuses from the recording medium in which the program is recorded and stores the program in storage apparatus  106 . Alternatively, network card  108  communicates with the server apparatus connected to the network so that a program for implementing the functions of the above-described apparatuses downloaded from the server apparatus is stored in storage apparatus  106 . 
         [0194]    CPU  103  then copies the program stored in storage apparatus  106  to RAM  105  and sequentially reads out and executes commands included in the program from RAM  105 , thereby implementing the functions of the above-described apparatuses. 
         [0195]    Further, the technique described in the above-described embodiments can be implemented in a type, for example, a type of cloud service described below. However, the type in which the technique described in the above-described embodiments can be implemented is not limited to this. 
         [0196]    (Service Type 1: Own Data Center Type) 
         [0197]      FIG. 20  illustrates service type 1 (own data center type). This type is a type in which service provider  12  acquires information from group  10  and provides service to the user. In this type, service provider  12  has a function of data center operating company  11 . Specifically, service provider  12  holds cloud server  11   a  which manages big data. Accordingly, data center operating company  11  does not exist. 
         [0198]    In this type, service provider  12  operates and manages data center (cloud server  11   a ) ( 110   c ). Service provider  12  further manages OS ( 110   b ) and application ( 110   a ). Service provider  12  provides service using the OS ( 110   b ) and the application ( 110   a ) managed by service provider  12  ( 110   d ). 
         [0199]    (Service Type 2: IaaS-Based Type) 
         [0200]      FIG. 21  illustrates service type 2 (IaaS-based type). Here, IaaS is abbreviation of Infrastructure as a Service, and is a cloud service provision model in which an infrastructure itself for building and operating a computer system is provided as service via the Internet. 
         [0201]    In this type, data center operating company  11  operates and manages a data center (cloud server  11   a ) ( 110   c ). Further, service provider  12  manages OS ( 110   b ) and application ( 110   a ). Service provider  12  provides service using the OS ( 110   b ) and the application ( 110   a ) managed by service provider  12  ( 110   d ). 
         [0202]    (Service Type 3: PaaS-Based Type) 
         [0203]      FIG. 22  illustrates service type 3 (PaaS-based type). Here, PaaS is abbreviation of Platform as a Service, and is a cloud service provision model in which a platform which becomes a base for developing and operating software is provided as service via the Internet. 
         [0204]    In this type, data center operating company  11  manages OS ( 110   b ) and operates and manages a data center (cloud server  11   a ) ( 110   c ). Further, service provider  12  manages application ( 110   a ). Service provider  12  provides service using the OS ( 110   b ) managed by data center operating company  11  and the application ( 110   a ) managed by service provider  12  ( 110   d ). 
         [0205]    (Service Type 4: SaaS-Based Type) 
         [0206]      FIG. 23  illustrates service type 4 (SaaS-based type). Here, SaaS is abbreviation of Software as a Service. SaaS is, for example, a cloud service provision model which has a function of enabling a company or a person (user) which does not have data center (cloud server  11   a )  110   c  to use application  110   a  provided by a platform provider having data center (cloud server  11   a )  110   c  via a network such as the Internet. 
         [0207]    In this type, data center operating company  11  manages application ( 110   a ), manages OS ( 110   b ) and operates and manages a data center (cloud server  11   a ) ( 110   c ). Further, service provider  12  provides service using the OS ( 110   b ) and the application ( 110   a ) managed by data center operating company  11  ( 110   d ). 
         [0208]    In any of the above-described types, it is assumed that service provider  12  provides service. Further, for example, service provider  12  or data center operating company  11  itself may develop OS  110   b , application  110   a  or database, or the like, of big data or may outsource the development to the third party. 
         [0209]    The disclosure of Japanese Patent Application No. 2013-203604, filed on Sep. 30, 2013, including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
       INDUSTRIAL APPLICABILITY 
       [0210]    The server apparatus, the information equipment, the receptacle, the electric charging information generation method and the electric charging information generation program according to the present invention are suitable for use in a system for providing electric charging service. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1 ,  2  User 
           10  Group 
           10   a ,  100 ,  200 ,  900 ,  1000  Equipment 
           10   b  Gateway 
           11  Data center operating company 
           11   a  Cloud server 
           12  Service provider 
           12   a  Server 
           20  Register 
           21 ,  31 ,  51  Input section 
           22 ,  32 ,  52  Display section 
           23 ,  53 ,  82  Wired communication section 
           24 ,  33 ,  41 ,  81  Radio communication section 
           25 ,  34 ,  42 ,  54 ,  83  Storage section 
           25   a ,  34   b ,  83   b  Purchase amount information 
           26 ,  35 ,  44 ,  55 ,  85  Control section 
           30  Information equipment 
           34   a ,  83   a  User ID 
           34   c ,  42   a ,  83   c  Electric charging period information 
           36  Plug 
           36   a  LED 
           40 ,  80  Receptacle 
           43 ,  84  Electric charging section 
           50  Server apparatus 
           54   a  Electric charging bonus point information 
           54   b  Store information 
           54   c  Crowded degree adjustment information 
           54   d  User information 
           55   a  Generating section 
           55   b  Store information output section 
           55   c  Assigning section 
           55   d  Issuing section 
           60  Base station apparatus 
           70  Network 
           100  Computer 
           101  Input apparatus 
           102  Output apparatus 
           103  CPU 
           104  ROM 
           105  RAM 
           106  Storage apparatus 
           107  Reading apparatus 
           108  Network card 
           109  Bus 
           110   a  Application 
           110   b  OS 
           110   c  Data center (cloud server) 
           110   d  Service provision
Provided is a server device whereby more customers are gathered at a store, and the spending per customer is increased. In a server device ( 50): a storage unit ( 54) stores charging parameters corresponding to purchase costs; a wired communication unit ( 53) receives information of the purchase cost which is inputted into a cash register; and a generating unit ( 55 a) retrieves, from the charging parameters which are stored in the storage unit ( 54), the charging parameter corresponding to the purchase cost which is received by the wired communication unit ( 53), and, on the basis of the charging parameter, generates charging information which indicates either the charging time or the charging quantity at which a power outlet carries out charging.