Image forming apparatus and control method of image forming apparatus

An image forming apparatus includes a power supply unit supplying power to a plurality of components, the power supply unit including a first power mode and a second power mode, the second power mode supplying less power than the first power mode, a control unit controlling which power mode the power supply unit uses, an authentication unit performing a user authentication when power is supplied from the power supply unit in the second power mode and an authentication request received in the second power mode, and a sending unit sending a request signal requesting the control unit to shift the power supply unit to the first power mode when the authentication unit succeeds in the user authentication, wherein the control unit controls the power supply unit to shift from the second power mode to the first power mode upon receipt of the request signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image forming apparatus which has an energy-saving mode, a normal mode, and a control method thereof.

2. Description of the Related Art

In the conventional image forming apparatus, an authentication is performed by an identification (ID) card which stores a user's identification information, and the user who is correctly authenticated is allowed to use the image forming apparatus. Accordingly, the apparatus can be managed and security is enhanced.

For purposes of saving energy, the image forming apparatus includes an energy-saving mode (also referred to as power-saving mode or sleep mode) for shutting down electric power supply to some parts of the image forming apparatus. When user authentication is performed under the energy-saving mode, the image forming apparatus recovers from the energy-saving mode to the normal mode. (For instance, see Japanese Patent Application Laid-Open No. 2006-47765)

In a technique discussed in Japanese Patent Application Laid-Open No. 2006-47765, since a controller of an image forming apparatus main body performs the user authentication after detecting an ID card, a power supply to the controller needs to be maintained even during the energy-saving mode. As a result, further power saving cannot be achieved.

Another power savings issue can arise if user authentication fails. For example, if the image forming apparatus only performs detection of the ID card under the energy-saving mode, the image forming apparatus recovers from the energy-saving mode to the normal mode in response to detection of the ID card and then performs the user authentication using an external authentication apparatus after recovering to the normal mode. In this example, there is no power use issue if the authentication succeeds since the user will be allowed to operate the image forming apparatus. In the event the user authentication fails, since the image forming apparatus still needed to recover from the energy-saving mode, unnecessary power is consumed until the image forming apparatus shifts back to the energy-saving mode.

In addition, components of the image forming apparatus which have an upper limit for a number of activations will uselessly consume their lifetime because the image forming apparatus unnecessarily recovers from the energy-saving mode. Such components include, but are not limited to, a hard disk (HDD), a relay which turns electric power supply on/off in a power supply unit, and a fuse used in the power supply unit.

SUMMARY OF THE INVENTION

The present invention is directed to an image forming apparatus which can reduce useless power consumption and avoid shortening the lifetime of components with an upper limit for a number of activations by preventing the image forming apparatus from unnecessarily recovering from an energy-saving mode.

According to an aspect of the present invention, an image forming apparatus which includes a plurality of components includes a power supply unit configured to supply power to the plurality of components, wherein the power supply unit includes a first power mode and a second power mode, wherein the second power mode supplies less power than the first power mode, a control unit configured to control which power mode the power supply unit is to use, a first authentication unit, to which power is supplied from the power supply unit while in the second power mode, wherein the first authentication unit performs a first user authentication when an authentication request has been received in the second power mode, and a sending unit configured to send a request signal to request the control unit to shift the power supply unit to the first power mode when the first authentication unit has succeeded in the first user authentication, wherein the control unit controls the power supply unit to shift from the second power mode to the first power mode upon receipt of the request signal.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1illustrates an example of a system configuration including a multifunction peripheral (MFP) which is an example of an image forming apparatus in the present exemplary embodiment.

An MFP101is a multifunction image forming apparatus provided with functions of a copy, a scanner, a FAX, a printer and the like. Client personal computers (PCs)102and103can send print jobs to the MFP101, and receive scanned data from the MFP101. A local area network (LAN)104is a network in which the MFP101, the client PCs102and103are connected to each other. The LAN104uses a system, for instance, Ethernet® or the like, and can send/receive data to/from apparatuses connected to another LAN via the MFP101, client PCs102and103, and Internet network105.

An authentication server107is a server for authenticating a user who uses the MFP101, and sends/receives data to/from the MFP101via the LAN106and the Internet network105. User information (e.g., user code) is sent from the MFP101to the authentication server107, and the authentication server107performs the authentication by checking the user information with authentication information stored in the authentication server107. An authentication result is sent from the authentication server107to the MFP101.

A method for the MFP101to obtain the user information includes a method for inputting the user information from a button provided in the MFP101, and a method for inputting the user information from the ID card which the user owns via an ID card reading device. The authentication server107may be connected to the LAN104rather than the LAN106.

FIG. 2illustrates an example of an appearance of the MFP101. A document reading unit202optically reads a document and generates image data of the document. A sheet feeding unit206stores sheets of recording medium, and the user can add the sheets. A printer unit205prints an image on the sheet, and at the time of printing, transfers a toner image on the sheet conveyed from the sheet feeding unit206to fix it using a fixing device. The sheet(s) containing the printed image is discharged to a sheet discharging unit201.

An operation unit204includes a button for the user to input an instruction to the MFP101, and a display element such as a liquid crystal display which displays a status of the MFP101and an operation menu. Alternatively, the operation unit204may include a touch panel. A card reader unit203reads information stored in the ID card (not shown). The card reader unit203may have a function for writing data to the ID card.

FIG. 3is a block diagram illustrating an example of a hardware configuration inside the MFP101. A plug301is used to plug into an outlet of a commercial alternating current (AC) power supply, and supplies AC power to a power supply unit302. The power supply unit302supplies the power to each unit within the MFP101. The power supply unit302converts the AC voltage to suitable voltage for each unit, and converts an AC current to a direct current (DC), as the need arises, depending on the unit receiving the power.

A fuse210and a relay212are provided inside the power supply unit302. When an overcurrent or a short-circuit current flows within the power supply unit302, an internal fuse element of the fuse210is fused or shut off. Accordingly, the fuse210protects the power supply unit302or each unit of the MFP101to which the power supply unit302supplies the power. The relay212serves as a switch for supplying or cutting off the power from the power supply unit302to each unit inside the MFP101.

Both the fuse210and the relay212are devices which have a lifetime dependent on a number of times power is turned on or off. A fuse lifetime, for example, is dependent on a lifetime of a fuse element which deteriorates due to a rush current generated each time power is turned on. A relay lifetime, for example, is depending on a lifetime of contacts. A control unit303performs control of each unit within the MFP101, and performs control regarding processing and transfer of electronic data. A power supply control signal line304transmits a power supply control signal to the control unit303to control on/off of an output of the power supply unit302.

The MFP101has a normal operation mode in which the power is supplied to each unit included within the MFP101, and an energy-saving mode (may be referred to as power-saving mode, or sleep mode) in which power consumption is reduced by not supplying the power to some units. There is a limit in the number of times the MFP101can shift between the energy-saving mode and the normal mode before performance of the units of the MFP101begins to degrade. Accordingly, it is desirable that the number of times of the shifting is kept to a minimum.

In the MFP101of the present exemplary embodiment, the power supplied to the document reading unit202, the sheet discharging unit201, the printer unit205, and the sheet feeding unit206is shutdown in the energy-saving mode in order to reduce the power consumption. Further, for the control unit303and the operation unit204, the power supply unit302supplies power to only some elements of the control unit303and operation unit304and shuts down the power to other elements.

In the energy-saving mode, an element within the control unit303to which the power is supplied is a circuit which detects a trigger event for recovering from the energy-saving mode to the normal mode. The trigger event includes detection of insertion of the ID card, detection of FAX reception, detection of a print job received via a network, detection of a button operation in the operation unit204and the like.

When the MFP101is in the energy-saving mode, for a user who puts the ID card to be read or a user who operates a button in the operation unit204in order to use the MFP101, it is desirable that the operation unit204becomes usable as soon as possible. However, it may take a few seconds to several tens of seconds until the operation unit204becomes usable depending on software or hardware which controls the operation unit204.

FIG. 4is a block diagram illustrating an example of a hardware configuration of the control unit303.

A central processing unit (CPU)402executes processing in the control unit303. The CPU402executes a program loaded on a memory403.

An internal bus405is a bus for the CPU402to communicate with each block within the control unit303.

A hard disk (HDD)409stores programs (operating system (OS) and application programs and the like) which the CPU402executes. Further, the HDD409stores job data and image data. Job data refers to data for the MFP101to execute functions, such as page description language (PDL) data for print processing received via a LAN interface (I/F)407, for instance, from the client PCs102and103. The HDD409is an example of a device which has a lifetime dependent on a number of times of turning on the power.

A reader I/F404is an interface which delivers and receives a command, a status, and image data by communicating with the document reading unit202. A printer I/F410is an interface which delivers and receives a command, a status, and image data by communicating with the printer unit205. A FAX I/F408is an interface which is connected to a public telephone line to perform communication of FAX images. The LAN I/F407is connected to a network such as Ethernet® to deliver and receive job data, a command, and a status.

An operation unit I/F406is an interface which performs communication with the operation unit204, and performs sending of data to be displayed on a display unit504, and reception of input information from a user using, for example, a button and a touch panel. The power supply control unit401is a block which controls the shift between the normal mode and the energy-saving mode of the MFP101. The power supply control unit401sends or changes the power supply control signal transmitted to the power supply unit302via the power supply control signal line304so that the MFP101shifts from the normal mode to the energy-saving mode based on a command from the CPU402.

In the energy-saving mode, the power supply control unit401monitors start signals transmitted via activation signal lines (412,414, and416) from the operation unit I/F406, the LAN I/F407, and the FAX I/F408. If a change occurs in the start signal, the power supply control unit401sends or changes the power supply control signal so that the MFP101recovers from the energy-saving mode to the normal mode. The power supply unit302supplies or stops the power to units included in the MFP101according to the power supply control signal.

FIG. 5is a block diagram illustrating an example of a hardware configuration of the operation unit204. A CPU503executes a program utilizing a memory507as a working area to control the entire operation unit204.

The memory507is a storage unit which includes a nonvolatile program memory and a rewritable temporary memory. The program memory stores a program which the CPU503executes. The rewritable temporary memory is used as the working area of the CPU503.

The display unit504displays data received from the control unit303via a host I/F508on a liquid crystal display (LCD) provided in the display unit504. A button unit506includes a press button or a touch panel overlaid on the LCD on the display unit504. Upon detecting an operation (e.g., press) of the button unit506, the CPU503sends information indicating detection of the operation to the control unit303via the host I/F508.

The card reader unit203is connected to a card reader I/F502. The card reader unit203is controlled by the CPU503and performs sending/receiving of data to/from a card501(ID card, etc.).

Each block within the operation unit204is connected to an internal bus505.

In the energy-saving mode, the CPU503does not supply the power which has been supplied from the power supply unit302to the operation unit204to the display unit504for purpose of reduction of power consumption. The CPU503controls shutting off of a backlight of the liquid crystal display of the display unit504. In the present exemplary embodiment, a processing capability of the CPU503and a memory capacity of the memory507are designed based on a limited specification to reduce the power consumption.

FIG. 6is a block diagram illustrating an example of a hardware configuration of the card reader unit203which is an example of a medium information reading unit. A control unit603controls a sending unit602, a receiving unit604, and an antenna601, based on control by the CPU503of the operation unit204, and performs sending/receiving of data to/from the operation unit204.

The sending unit602converts sending data into a signal suitable for the antenna601. The receiving unit604converts a signal which the antenna601has output into receiving data. The antenna601converts a signal input from the sending unit into an electromagnetic wave. If the card501is a non-contact type card in which a battery is not incorporated, the antenna601generates a magnetic field for supplying the power to the card501. Further, the antenna601converts the electromagnetic wave output by the card501into a signal, and outputs the converted signal to the receiving unit604.

The card reader unit203of the present exemplary embodiment is assumed to be a card reader which reads non-contact type IC card. However, a card reader which reads a contact type IC card, or a magnetic recording type card reader may be used.

FIG. 7is a block diagram illustrating a hardware configuration of an ID card501(hereinafter, may be referred to as a card).

A CPU701performs control inside the card and communication with the card reader unit203. When the CPU701receives data from the card reader unit203, analysis of command and storage of the received data into the memory705are performed by the control of the CPU701. When the CPU701sends data to the card reader unit203, transfer of the data stored in the memory705to the sending unit602is performed by the control of the CPU701according to contents of a received command.

The memory705is a rewritable non-volatile memory, and a program code of the CPU701, user information, and card information are stored therein.

The sending unit702converts sending data into a signal suitable for an antenna704. The antenna704converts a signal input from the sending unit into an electromagnetic wave. Further, the antenna704receives an electromagnetic wave sent from the card reader unit203, and the receiving unit703converts a signal output by the antenna704into receiving data.

In the present exemplary embodiment, the card501is a non-contact type card in which a battery is not incorporated, and a power generation unit706may generate power to be used in the card501. A magnetic field generated in the card reader unit203is converted again into electric energy by the antenna704, and further converted into DC constant-voltage by the power generation unit706.

FIG. 12illustrates an example of card information stored in the card501in the present exemplary embodiment. The card information includes a card type, a name of vendor which produces the card, a serial number which is a specific number assigned by the card vendor, and a version number of a program installed in the card. These values are usually written in the card when the card is shipped from the card vendor.

FIG. 13illustrates an example of user information stored in the card501in the present exemplary embodiment. A group code is a value for identifying a corporation or a group to which a user belongs. An organization code is a value for identifying a section of the corporations or the group to which the user belongs. The group code or the organization code is also referred to as a division code which is an example of division information which defines a division. An individual code is an ID value for identifying a user individual. These values are written into the card according to an environment where it is used, after the card has shipped from the vendor who produces the card.

Next, processing for shifting the MFP101from the normal mode to the energy-saving mode, and processing for shifting the MFP101from the energy-saving mode to the normal mode will be described.

FIG. 8is a flowchart illustrating an example of processing in which the MFP101in the normal mode shifts to the energy-saving mode. The processing in the flowchart is executed by the CPU402which is included in the control unit303of the MFP101.

While the MFP101is operating in the normal mode, execution of the flowchart starts. First, in step S802, the CPU402determines whether there are factors for shifting to the energy-saving mode. In the present exemplary embodiment, the factors for shifting to the energy-saving mode include but are not limited to, when the button unit506of the operation unit204is not operated for a specified time, when predetermined time is arrived, a request for shifting to the energy-saving mode is input by a user's operation of the operation unit204, etc.

If there is the factor for shifting to the energy-saving mode (YES in step S802), the processing proceeds to step S804, and the CPU402notifies the operation unit204of the shifting to the energy-saving mode and sends a first authentication condition. The first authentication condition will be described in detail below.

In step S806, the CPU402issues an energy-saving mode shift command to the power supply control unit401. Based on the energy-saving mode shift command issued to the power supply control unit401, the power supply control unit401sends a power supply control signal to the power supply unit302via the power supply control signal line304. The power supply unit302stops the electric power supply to some units in the MFP101based on the received power supply control signal. Thus, the MFP101shifts to the energy-saving mode, and the processing in the flowchart is terminated.

During the energy-saving mode of the present exemplary embodiment, the power is supplied to the operation unit204and the card reader unit203. Further, in the control unit303, the power is supplied to a part of the operation unit I/F406, a part of the LAN I/F407, and a part of the FAX I/F408, and the power supply is stopped to the other parts. The power supply to the document reading unit202, the sheet discharging unit201, the printer unit205, and the sheet feeding unit206is stopped. It is only necessary that the energy-saving mode is in a status in which its power consumption amount is less than that of the normal mode. To which units the power will be supplied, and to which units the power supply will be stopped may be different from the present exemplary embodiment.

A first authentication and a second authentication in the present exemplary embodiment will now be described. When there is a request for the user authentication by the ID card during the energy-saving mode, the MFP101will not immediately shift to the normal mode, but the operation unit204performs a first user authentication (hereinafter, referred to as a first authentication). Only if the first authentication has succeeded, will the MFP101shift to the normal mode. Then, a second user authentication (hereinafter, referred to as a second authentication) is executed. If the first authentication has not succeeded, the MFP101maintains the energy-saving mode, and does not shift to the normal mode.

In order to perform the first authentication, the CPU503of the operation unit204stores authentication condition and authentication data in the memory507in advance, and performs the authentication by checking the authentication condition and authentication data with the card information and the user information obtained from the card501. In step S804ofFIG. 8, in order to enable the operation unit204to execute the first authentication during the energy-saving mode, the CPU402of the control unit303notifies the operation unit204of the authentication condition for performing the first authentication. Then, in steps S1004and S1006of the flowchart ofFIG. 10, as will be described below, the operation unit204stores the notified authentication condition.

In order to reduce the power consumption in the energy-saving mode, processing speed of the CPU402of the operation unit204and the memory capacity of the memory507is limited. Therefore, all of the authentication condition and an authenticable data array which the authentication server107includes cannot be stored in the memory507. Further, the operation unit204cannot perform all the authentication processing which the authentication server107performs. In the energy-saving mode, since the operation unit204cannot send and receive data to and from the authentication server107via the LAN I/F407, the operation unit204also cannot perform the authentication processing using the authentication server107without recovering to the normal mode.

Therefore, in the first authentication, unnecessarily shifting the MFP101to the normal mode when the processing speed of the CPU503of the operation unit204and the capacity of the memory507are limited can be avoided.

If the first authentication has succeeded, when the MFP101shifts to the normal mode and it can communicate with the authentication server107via the network, the MFP101requests the authentication server107to perform user authentication. In the present exemplary embodiment, this is referred to as a second authentication.

In the present exemplary embodiment, a condition of an authentication performed by the authentication server107, namely, a condition (condition 1) of the second authentication will be described as follows.

<Condition 1>A card type (kind of card) is equal to Type A, and,a group code is equal to 0033, and,an individual code is equal to an authenticable data array.

The condition in the first authentication performed by the operation unit204is a condition which relaxes the condition of the second authentication. For instance, as an example which relaxes the above-described condition 1, a condition (condition 2) for the first authentication will be described as follows.

<Condition 2>A card type (kind of card) is equal to Type A, and,a group code is equal to 0033.
A condition expression indicated in the condition 2 includes two AND conditions, namely, the condition that the card type is equal to Type A, and the condition that the group code is equal to 0033. The condition that the individual code is equal to the authenticable data array, included in the condition 1, is omitted in the condition 2.

Therefore, a data array which represents an individual code to which the authentication is permitted does not need to be stored in the memory507of the operation unit204, so that the memory capacity can be saved. In particular, it is more effective when the data amount of the data array which indicates the user code to which the authentication is permitted is large.

When the user authentication is attempted using a different type of ID card, or using an ID card on which a correct division code is not recorded, it will fail in the first authentication. In such a case, the shift from the energy-saving mode to the normal mode will not be performed, thus preventing an unnecessary recovery from the energy-saving mode.

If the first authentication has succeeded, the MFP101recovers from the energy-saving mode to the normal mode, and the second authentication is performed in the control unit303. Processing of the second authentication will be described below.

FIG. 9is a flowchart illustrating an example of processing of recovery from the energy-saving mode of the MFP101and the user authentication. The processing in the flowchart is executed by the CPU402which is included in the control unit303of the MFP101.

The processing of the flowchart is started based on a request for the recovery from the energy-saving mode that has been received from the operation unit204. The power supply control unit401is notified of the recovery request via the host I/F508of the operation unit204and the operation unit I/F406of the control unit303. Then, the power supply control unit401supplies the power to the control unit303, so that each device within the control unit303is activated, and the CPU402starts to execute the processing in the flowchart. Processing until the operation unit204issues the recovery request to the control unit303will be described below.

In step S902, the CPU402initializes each unit inside and outside the control unit303and shifts the MFP101to the normal mode. By shifting from the energy-saving mode to the normal mode, the lifetime of components which have an upper limit in the number of activations will be consumed by one time.

Then, in step S904, the CPU402requests the operation unit204for the card information and the user information stored on the card501. In step S906, the CPU402receives the card information and the user information sent from the operation unit204in response to the request.

Then, in step S908, the MFP101requests the authentication server107to perform the user authentication by sending the card information and the user information thereto. The authentication server107performs the authentication processing by checking the card information and the user information sent from the MFP101with the authentication condition and the authentication data stored in the authentication server107, and determines whether the user authentication has succeeded or failed. Then, the authentication server107sends back a determination result to the MFP101. The processing in the MFP101in step S908and the authentication processing in the authentication server107correspond to the second authentication in the present exemplary embodiment. The authentication server107determines whether the authentication has succeeded or failed based on the above-described condition 1.

In step S910, the CPU402checks a result of the user authentication sent back from the authentication server107. If the authentication has succeeded (YES in step S901), the processing proceeds to step S912. If the authentication has failed (NO in step S901), the processing proceeds to step S916.

In step S912, the CPU402notifies the operation unit204that the user authentication has succeeded, and causes the display unit504of the operation unit204to display that the user authentication has succeeded. Then, instep S914, the CPU402causes the display unit504of the operation unit204to display a normal operation menu, puts it into a state in which a user can operate the MFP101, and the processing in the flowchart is terminated.

If, in step S910, the authentication has failed (NO in step S910), then in step S916, the CPU402notifies the operation unit204that the user authentication has failed, and causes the display unit504of the operation unit204to display that the user authentication has failed. Then, in step S918, the CPU402shifts the MFP101to the energy-saving mode again, and the processing in the flowchart is terminated.

FIG. 10is a flowchart illustrating an example of processing in the operation unit204when the MFP101shifts to the energy-saving mode. The processing in the flowchart is executed by the CPU503of the operation unit204. While the MFP101is in the normal mode execution of the processing in the flowchart begins.

In step S1002, the CPU503waits to receive notification from the control unit303. If there is notification (YES in step S1002), the processing proceeds to step S1004. In step S1004, the CPU503receives the first authentication condition and notification of shifting to the energy-saving mode via the host I/F508from the control unit303. In this case, the notification corresponds to the notification sent from the control unit303in step S804of the flowchart ofFIG. 8.

Then in step S1006, the CPU503stores the received first authentication condition in the memory507. Then, instep S1008, the CPU503switches off the backlight of the liquid crystal display of the display unit504, and the processing in the flowchart is terminated. In parallel with the processing in the flowchart, the MFP101will shift from the normal mode to the energy-saving mode.

FIG. 11is a flowchart illustrating an example of processing of sending of a request for recovery from the energy-saving mode and the first authentication processing in the operation unit204under the energy-saving mode. Ina state after the execution of the processing in the flowchart ofFIG. 10, the execution of the processing in the flowchart ofFIG. 11is started.

In step S1102, the CPU503determines whether the card501is detected. Upon supplying the power to the antenna601of the card reader unit203, if the card501is present in the vicinity, the CPU503issues a command to the card501to send a response. If the response has not been obtained (NO in step S1102), it is determined that the card501could not be detected. If the response has been obtained (YES in step S1102), it is determined that the card501could be detected. Based on the detection of the card501, the CPU503determines that there is a request for the user authentication using the card.

In step S1104, upon determining that there is a request for the user authentication, the CPU503issues a command to the card501to send card information and user information, and reads out the card information and the user information sent from the card501as the response. Then, in step S1106, the CPU503determines whether the card information and the user information have been successfully read. If it is determined that the information from the card has been successfully read (YES in step S1106), the processing proceeds to step S1108. If it is determined that the information has not successfully been read, the processing returns to step S1102.

In step S1108, the CPU503performs the first authentication. More specifically, the CPU503checks the card information and the user information read in step S1104with the first authentication condition stored in the memory507in step S1004ofFIG. 10. Then, in step S1110, the CPU503determines whether the first authentication has succeeded. If it is determined that the first authentication has succeeded (YES in step S1110), the processing proceeds to step S1112. If it is determined that the first authentication has failed (NO in step S1110), the processing returns to step S1102.

In step S1112, the CPU503sends a recovery request signal to the control unit303for making a request for shifting (recovering) from the energy-saving mode to the normal mode. Therefore, the request signal is transmitted to the power supply control unit401of the control unit303, and the processing in the flowchart ofFIG. 9is executed. Accordingly, the CPU503executes the processing for shifting the MFP101to the normal status.

When the MFP101is shifted to the normal status, a request for the card information and the user information is made from the control unit303according to the processing of step S904ofFIG. 9. If the CPU503receives the request (YES in step S1114), the processing proceeds to step S1116, and the CPU503sends the card information and the user information read in step S1104to the control unit303.

As described above, the MFP101is shifted from the energy-saving mode to the normal mode on the condition that the first authentication has succeeded on the card501detected by the operation unit204under the energy-saving mode. Accordingly, the MFP101can be prevented from erroneously recovering from the energy-saving mode, by, for instance, placing a wrong card to the card reader unit203. Thus, unnecessary power consumption by the MFP101due to unnecessary recovery from the energy-saving mode can be prevented, and shortening the lifetime of components which have an upper limit in a number of activations can be avoided.

In the present exemplary embodiment, the condition 2 for the first authentication is assumed to be obtained by deleting the condition “the individual code is equal to the authenticable data array” from the condition 1 for the second authentication. The condition 2 may include conditions other than the above-described example. Other variations for the condition 2 will be described below. The condition 1 which is the authentication condition in the authentication server107is as described above.

Another condition (condition 3) for the first authentication will be described below.

<Condition 3>A card type (kind of card) is equal to Type A, and,a group code is equal to 0033, and,an individual code is greater than 00000111, and,an individual code is smaller than 00011240.

According to the condition 3, the condition is stricter than the condition 2 on the point of further checking whether a value of the individual code is in a certain range. By adding the condition for checking whether the value of the individual code is in a certain range, a consumption amount of the memory507can be reduced. However, the first authentication will be accepted (OK) on individual codes which are not included in the authenticable data array ofFIG. 14such as 00000113 and 00000114, although the second authentication will not be accepted (NG) on cards which include these individual codes.

Another condition (Condition 4) for the first authentication will be described as follows.

<Condition 4>A card type (kind of card) is equal to Type A, and,a group code is equal to 0033, and,an individual code is not equal to unauthenticable data array.

The condition 4 can be implemented by storing a part of the authentication data which is not included in an authenticable data array in the memory507as an unauthenticable data array. The unauthenticable data array may include values which are not included in the authenticable data array, for instance, as illustrated inFIG. 14.FIG. 15illustrates a sample of the unauthenticable data array. If a number of the unauthenticable data is small, this method has the effect of reducing a use amount of the memory507.

The unauthenticable data array may not include all values which are not included in the authenticable data array. If there is detected a card which includes a value which is included neither in the authenticable data array used in the authentication server107, or in the unauthenticable data array used in a first authentication unit, the first authentication unit will accept (OK) the user authentication, and it is determined as unacceptable (NG) by a second authentication unit.

The unauthenticable data array described in the condition4may not be fixed data, and may be dynamically changed based on a result of past user authentication. An example of dynamically generating the unauthenticable data based on the result of past user authentication will be described below.

FIG. 16illustrates an example of a history of the authentication results to be used for creating the first authentication condition in the present exemplary embodiment. The CPU402of the control unit303adds authentication results to a history file stored in the HDD409in the process of the second authentication, by which the history will be accumulated. In this history, there are four cases in which the authentications have failed (NG) (records of Nos. 4, 6, 8, and 12), and three cases (records of Nos. 4, 6, and 12) among these are attributable to non-coincidence of individual codes.

FIG. 17illustrates an example of the unauthenticable data array included in the first authentication condition in the present exemplary embodiment. The unauthenticable data array in this example is made up of only user codes which have failed in the authentication (NG) in the history. Since it is likely that a user who has failed authentication (NG) is present near the MFP101and will attempt the authentication again, a detection ratio of authentication failure (NG) can be improved. Further, authentication results under the normal mode may be added to the history. The more the number of histories is, the more the detection ratio of the authentication failure (NG) can be improved.

By utilizing the history of past authentication results, the detection ratio of the cards which fail in the first authentication can be improved while suppressing a capacity for the unauthenticable data array in small.

In the present exemplary embodiment, although an MFP which is a multifunction image forming apparatus is described as an example of an image forming apparatus, the present invention can be applied to an image forming apparatus, e.g., copy machine, facsimile apparatus, printer, etc., having a single function.

While the present exemplary embodiment is based on the premise of using a non-contact type IC card which does not include a battery, a non-contact type IC card which includes a battery may be used. Alternatively, a contact type IC card maybe used. In this case, the card reader203will use a contact type IC card reader.

The MFP101may be designed to perform the second authentication by itself without using the authentication server107. In that case, the user authentication can be realized by the MFP101by providing functions and data that the authentication server107stores to perform the user authentication for the control unit303.

As described above, according to the present exemplary embodiment, by utilizing the history of the past authentication results, the detection ratio of the cards which fail (NG) in the authentication by the first authentication unit can be improved while suppressing the capacity for the unauthenticable data array to be stored in the memory507in small. Therefore, the MFP101in the energy-saving mode can reduce a number of times of unnecessarily recovering to the normal mode so that the MFP101can avoid unnecessary consumption of electric power, and shortening a lifetime of components which have an upper limit in a number of activations.

This application claims the benefit of Japanese Patent Application No. 2008-301216, filed Nov. 26, 2008, which is hereby incorporated by reference herein in its entirety.