Patent Description:
Image forming apparatuses and information processing apparatuses of recent years have had multiple functions and, therefore, have a problem in taking longer time from the operation of a power switch by a user to an operable state in which the user can actually operate the apparatus.

Some apparatuses have a function called "suspend" (suspend mode) to deal with such a problem. When a user performs the OFF operation on a power switch, the operation of a program in execution is suspended by the suspend function such that the program can return to an operation state which is substantially the same as the current operation state.

Moreover, some apparatuses have a function called "resume". This resume function activates the apparatus in an operation state which is substantially the same as the state at the time of termination of a preceding operation when a user performs the ON operation on a power switch. That is, the operation state returns to a preceding state when the user turns on the power switch.

According to the suspend function, the image forming apparatus in a normal operation mode can shift to the suspend mode, which causes an operation of each unit to be suspended, while the apparatus remains in a state immediately before suspension of the operation.

According to the resume function, moreover, the image forming apparatus in the suspend mode can return to the normal operation mode in a state immediately before shifting to the suspend mode.

Thus, these functions enable the image forming apparatus, such as a digital multifunction peripheral, to be activated at high speed, thereby promptly returning the image forming apparatus to a preceding operation state.

Moreover, the high-speed activation technique for retaining these memory values has a problem in which when the apparatus is shifted to the suspend mode during execution of processing, time elapses while processing is being interrupted.

<CIT> discusses an image forming apparatus which remains in a power-saving shift reserved state until a predetermined time elapses even when a power-saving shift key is operated.

If the high-speed activation technique retaining a memory value, for example, a suspend mode, is used for a power switch of the apparatus, a shift of the apparatus to the suspend mode during execution of processing such as a job causes the following phenomena.

Since the power switch is primarily used as a function of turning off the apparatus, the job interrupted by the switch-off should not be executed.

Moreover, even when the apparatus remains in the power-saving shift reserved state until a predetermined time elapses in spite of operation of the power-saving shift key as discussed in <CIT>, similar problems may occur in a case where a job in execution or a job on standby is not completed within a predetermined time period.

<CIT> describes a procedure through which a device is started up when power is introduced. An image processing apparatus, which enables execution of a plurality of jobs by starting up a plurality of software modules, is configured to, in a case where a job being executed is suspended, store information indicating status of execution of the job at the time of suspension. The suspended job is resumed based on the execution information. Specifically, in resuming the suspended job, a group of software modules relating to the suspended job is started up before other software modules.

<CIT> describes an information processing apparatus used to reduce power supply to nonvolatile memory when in power saving mode. To accomplish this, the information processing apparatus stores data in the nonvolatile memory that can be used in power saving mode to a volatile memory to which power will still be supplied while in power saving mode. Further, the information processing apparatus enables the operating system to recognize the storage area in which the data is stored as a replacement for the nonvolatile memory.

The present invention is directed to an image forming apparatus capable of being activated at high speed when the OFF operation of a power switch is performed. Moreover, the image forming apparatus is capable of preventing a problem caused by a job interrupted by suspension such that the problem does not occur after activation of the image forming apparatus even when the image forming apparatus is activated from a suspend state by the ON operation of the power switch, the suspend state being led by the OFF operation of the power switch during previous job execution.

According to a first aspect of the present invention, there is provided an image forming apparatus as specified in claims <NUM> to <NUM>. According to a second aspect of the present invention, there is provided a method as specified in claims <NUM> to <NUM>.

Further features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention.

Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the drawings.

<FIG> is a block diagram illustrating a schematic configuration of a multifunctional peripheral (MFP) <NUM> as an image forming apparatus according to an exemplary embodiment of the present invention. The MFP <NUM> has multiple functions such as a copy function, a printer function, and a scanner function.

In <FIG>, an MFP controller unit <NUM> controls the entire MFP <NUM>. A printer unit <NUM> performs image processing according to, for example, an electrophotographic method. A scanner unit <NUM> optically reads an image from a document and coverts the image into a digital image.

Moreover, a power supply unit <NUM> supplies power to each control unit of the MFP <NUM>. An operation unit <NUM> is used when a user operates the MFP <NUM>. A power switch unit <NUM> allows the user to perform an ON operation and an OFF operation of power supply, and is used to control a power supply state of the MFP <NUM>.

With such a configuration, the MFP <NUM> having the copy function, printer function, and scanner function is formed. A recording method of the printer unit <NUM> is not limited to the electrophotographic method as long as the printer unit <NUM> can perform image processing on two sides of a sheet-like recording medium (e.g., a recording sheet of paper). Alternatively, a recording method such as an inkjet method and a thermal transfer method may be used.

<FIG> is a block diagram illustrating a schematic configuration of the MFP controller unit <NUM> illustrated in <FIG>. In the following description, a description of the components that have already been described is not repeated.

In <FIG>, a power supply control unit <NUM> has a function of notifying a central processing unit (CPU) <NUM> of an ON operation or an OFF operation performed on the power switch unit <NUM> as interruption. Moreover, the power supply control unit <NUM> cuts off the power supply to each unit when the MFP <NUM> is shifted to a power saving mode, and supplies power to each unit when the MFP <NUM> returns from the power saving mode.

A reset unit <NUM> is a reset control unit for causing reboot processing to be executed by issuing a reset instruction to the CPU <NUM> and the entire system based on a control signal from the power supply control unit <NUM>. A field-effect transistor (FET) <NUM> is a switch used to turn on and off the power supply to a power supply system B <NUM>. An FET <NUM> is a switch used to turn off the power supply to a power supply system A <NUM> and the power supply system B <NUM>.

The CPU <NUM> is a control unit for controlling the entire MFP <NUM>. A memory unit <NUM> is a volatile storage unit, such as a double data rate synchronous dynamic random-access memory (DDR SDRAM).

An image processing unit <NUM> is a control unit for performing processing, such as compression of data from the scanner unit <NUM> and outputting of image data processed by the CPU <NUM> to the printer unit <NUM>. A hard disk drive (HDD) unit <NUM> is an external storage apparatus, for example, a non-volatile storage unit, such as an HDD.

Next, a power system of the MFP controller unit <NUM> is described.

The present exemplary embodiment is described using an example case in which the suspend method is applied. In the suspend method, data is retained in a memory in a state that power consumption is less than that in a normal state and activation (back to the normal state) is performed at high-speed. However, other methods, for example, a hibernation method may be used.

Accordingly, when the OFF operation of the power switch unit <NUM> is detected, the MFP <NUM> executes suspend processing. In the suspend processing, the operation of a program in execution is suspended such that the MFP <NUM> can return to an operation state substantially the same as an operation state at that time. Upon suspension of the operation in execution, the MFP <NUM> stores a system state in the memory unit <NUM>, and is shifted to a suspend state in which the power supply to the power supply system B <NUM> is cut off. Then, when the ON operation of the power switch unit <NUM> is performed next time, the MFP <NUM> restarts the program by returning to the system state. In the present exemplary embodiment, assume that the system state is a normal state. The suspend state is a power saving state in which a power consumption amount of the MFP <NUM> is less than that in the normal state. Moreover, the MFP <NUM> can also be shifted to another power saving state such as a hibernation state. That is, when a shift is made from the system state to the power saving state, the system state can be stored in the HDD unit <NUM> instead of the memory unit <NUM>, and the power supply to the memory unit <NUM> can be cut off.

The power supply system A <NUM> supplies power to the power supply control unit <NUM>, the reset unit <NUM>, and the memory unit <NUM>. Moreover, the power supply system A <NUM> supplies power to a portion of the CPU <NUM>. In any power saving mode, the power supply to the power supply system A <NUM> is not cut off so that the power supply system A <NUM> manages a power state of the entire MFP <NUM> and enables the MFP <NUM> to return from the power saving mode.

The power supply system B <NUM> supplies power to the CPU <NUM>, the image processing unit <NUM>, and the HDD unit <NUM>. The power cut-off and the power supply of the power supply system B <NUM> is controlled by controlling the FET <NUM> according to a control signal <NUM> output from the power supply control unit <NUM>.

The power cut-off of each of the power supply system A <NUM> and the power supply system B <NUM> is controlled by controlling the FET <NUM> according to a control signal <NUM> output from the power supply control unit <NUM>.

<FIG> is a block diagram illustrating a schematic configuration of the power supply control unit <NUM> illustrated in <FIG>.

In the power supply control unit <NUM>, a power state management unit <NUM> detects an OFF operation of the power switch unit <NUM>, and notifies the CPU <NUM> of a state of the power switch unit <NUM> via an interrupt signal <NUM>.

After detecting the state of the power switch unit <NUM>, the CPU <NUM> selects either (A) a shift to a suspend state or (B) a shift to a shutdown state, and executes the selected one. <If (A) a shift to the suspend state is selected>.

The CPU <NUM> notified of the state via the interrupt signal <NUM> executes processing for shifting the MFP <NUM> to the suspend state, in which power consumption is less than that in a normal state and activation is performed at high speed.

After the MFP <NUM> is shifted to the suspend state, the CPU <NUM> notifies the power supply control unit <NUM> of completion of the suspend shift processing via a suspend processing completion signal <NUM>.

Upon receipt of the suspend processing completion signal <NUM>, the power state management unit <NUM> controls the FET <NUM> via an FET control signal <NUM>, and cuts off the power supply to the power supply system B <NUM>. Moreover, when the ON operation of the power switch unit <NUM> is detected, the power state management unit <NUM> controls the FET <NUM> via the FET control signal <NUM>, and starts supplying power to the power supply system B <NUM>.

Herein, the FET <NUM> is open, and the power supply to the power supply system A <NUM> continues, while a CPU operation state is retained in the memory unit <NUM>. <If (B) a shift to the shutdown state is selected>.

The CPU <NUM> notified of the state via the interrupt signal <NUM> executes shutdown processing when determining that the system is terminated completely.

After termination processing of an application, the CPU <NUM> notifies the power supply control unit <NUM> of the completion of the shutdown processing via a system termination completion signal <NUM>.

When receiving the system termination completion signal <NUM>, the power state management unit <NUM> controls the FET <NUM> (see <FIG>) via an FET control signal <NUM> (see <FIG>), and cuts off the power supply to the power supply system A <NUM> and the power supply system B <NUM>. Thus, the power supply to the MFP <NUM> is completely turned off.

When the ON operation of the power switch unit <NUM> is performed after the power supply is completely turned off, the MFP <NUM> is activated by normal activation instead of suspend activation. In the normal activation, the FET <NUM> and the FET <NUM> are energized, thereby activating a system. The suspend activation is described below.

A timer unit <NUM> begins to measure a time from detection of the OFF operation of the power switch unit <NUM>. Simultaneously, an OFF-time monitoring unit <NUM> monitors whether the power state management unit <NUM> has received the suspend processing completion signal <NUM>. That is, if the MFP <NUM> is not shifted to the suspend state within a certain time although the power switch unit <NUM> is turned off, the timer unit <NUM> determines that software has hung, and the OFF-time monitoring unit <NUM> issues a hardware reset instruction to the reset unit <NUM>. The reset unit <NUM>, functioning as a safety device, issues a reset signal <NUM> to the CPU <NUM> to forcibly turn off the power supply. The arrangement of the timer unit <NUM> can avoid a trouble in which the power supply is not turned off although the power switch unit <NUM> is turned off.

A conventional shutdown sequence is described with reference to <FIG>.

<FIG> is a flowchart illustrating an example of the conventional shutdown sequence when a power switch is turned off.

The power supply control unit <NUM> notifies the CPU <NUM> of the interrupt signal <NUM> when the OFF operation of the power switch unit <NUM> by the user is detected. Upon receipt of the notification, the CPU <NUM> starts processing of the flowchart.

In step S401, the CPU <NUM> stops receiving a job as a batch of processing to be executed by the MFP <NUM> such that the job is not received during system termination.

In step S402, the CPU <NUM> forcibly terminates a current job in execution or a job on standby (an accumulated job) if there is any. When a job is forcibly terminated, a generation state of a current job is cleared regardless of the current job state. If a job is stored in a hard disk device, data of the job is cleared. If a job is retained on a memory, a state of the job is changed so that the job should never be executed.

Subsequently, in step S403, the CPU <NUM> issues a shutdown command to the system, and termination processing is performed on the system such as kernel.

When the system termination processing is completed, the operation proceeds to step S404. In step S404, the CPU <NUM> issues the system termination completion signal <NUM>, and cuts off the power supply to the power supply system A <NUM> and the power supply system B <NUM>. Thus, the electricity to the MFP <NUM> is completely turned off. When the power switch unit <NUM> is turned on next time, the system is reset and activated.

In the above-mentioned conventional sequence, since a state of the memory unit <NUM> is cleared, high-speed activation cannot be achieved.

Next, a description is given of processing by the MFP <NUM> according to the present exemplary embodiment when a power switch is turned off with reference to <FIG>.

<FIG> is a flowchart illustrating an example processing by the MFP <NUM> according to the present exemplary embodiment when the power switch unit <NUM> is turned off. The processing of this flowchart is performed by the CPU <NUM> by reading and executing a computer-readable program stored in the HDD unit <NUM> or the memory unit <NUM>.

In step S501, the CPU <NUM> stops receiving a job as a batch of processing to be executed by the MFP <NUM> such that the job is not received during system termination. The CPU <NUM> also starts measuring a time-out time for step S504, which is described below.

In step S502, the CPU <NUM> forcibly terminates a current job in execution or a job on standby (an accumulated job) if there is any. When a job is forcibly terminated, a generation state of a current job is cleared regardless of the current job state. If a job is stored in a hard disk device, data of the job is cleared. If a job is retained on a memory, a state of the job is changed so that the job should never be executed.

Subsequently, in step S503 and step S504, the CPU <NUM> monitors, with time-out, whether there is any remaining job (whether all the jobs are completely terminated). In step S504, the CPU <NUM> determines whether the time-out has occurred based on a first time is shorter than a second time. The first time elapses from detection of the OFF operation of the power switch unit <NUM> to determination of time-out, and the second time elapses from the OFF operation of the power switch unit <NUM> to a time when the timer unit <NUM> determines that the MFP <NUM> needs to be reset.

If the CPU <NUM> determines that all the jobs are terminated completely (there is no job) before the time-out time elapses (NO in step S503), the operation proceeds to step S505. In step S505, the CPU <NUM> executes suspend shift processing, and the system enters into an interruption state. Moreover, after shifting to the suspend state, the CPU <NUM> notifies the power supply control unit <NUM> of the suspend processing completion signal <NUM>. Upon receipt of the suspend processing completion signal <NUM>, the power supply control unit <NUM> cuts off the power supply to the power supply system B <NUM>, thereby shifting the system to the suspend state.

On the other hand, if the CPU <NUM> determines that the absence of the job is not detected (there is still a job to be terminated) (YES in step S503), and determines that the time-out of a job termination waiting period has occurred (YES in step S504), then the operation proceeds to step S510. In step S510, the CPU <NUM> abandons the suspend processing, and shuts down the system. In step S511, the CPU <NUM> performs an existing power off operation.

That is, in step S510, the CPU <NUM> issues a shutdown command to the system, and performs termination processing on the system such as kernel.

When the system termination processing is completed, the operation proceeds to step S511. In step S511, the CPU <NUM> issues the system termination completion signal <NUM> to the power state management unit <NUM>, and the power state management unit <NUM> issues the control signal <NUM> to the FET <NUM>. According to these signals, the CPU <NUM> cuts off the power supply to the power supply system A <NUM> and the power supply system B <NUM>. Thus, the system of the MFP <NUM> is properly terminated, and the electricity is completely turned off. When the power switch unit <NUM> is turned on next time, the system is reset and activated.

Therefore, when the user performs the OFF operation on the power switch unit <NUM>, the MFP <NUM> according to the present exemplary embodiment performs cancel processing for cancelling a job in execution or a job on standby. If the job in execution or the job on standby can be cancelled by the cancel processing, the MFP <NUM> is shifted to the suspend state. On the other hand, if the job in execution or the job on standby cannot be cancelled by the cancel processing, the MFP <NUM> is shifted to the OFF state.

As illustrated in <FIG>, the MFP <NUM> according to the present exemplary embodiment includes the timer unit <NUM>, so that the power supply of the MFP <NUM> is reliably turned off within a certain time when the power switch unit <NUM> is turned off. That is, the MFP <NUM> includes an emergency unit for reliably turning off the power supply thereof. The emergency unit is an important element of the MFP <NUM>. However, if termination of a job takes time after execution of the forcible termination processing on the job (step S502), the system is reset by the timer unit <NUM> during the job termination processing, causing forcibly cutting off the power supply to the MFP <NUM> with the system remaining interrupted.

Consequently, the MFP <NUM> according to the present exemplary embodiment has the time-out processing in step S504. Thus, before the power supply is cut off by the timer unit <NUM>, the time-out is determined in step S504 and a shutdown is performed such that the system is normally terminated.

Any of a case where the system is normally terminated by a shutdown and a case where the system is forcibly terminated by the timer unit <NUM> with the system interrupted, the system is cold-booted (normal activation) when the power supply is turned on next time. During the cold boot, the system is determined as to whether a previous job thereof was terminated normally. In a case where the system was not terminated normally in the previous job operation, there is a possibility that, for example, recovery processing needs to be performed. Accordingly, the system should be terminated normally.

If suspend is used in a normal sleep function (i.e., a user operation or a job is not received for a predetermined time period), completion of a job can be waited, and then the system is shifted to the suspend state. On the other hand, if suspend is used by turning off a power switch, a situation differs from that in the normal sleep function. However, a cutoff of the power supply in a forcible manner should not always be performed with the system remaining interrupted without normal termination.

In the present exemplary embodiment, generally, even if termination of a job takes time, the time-out is determined in step S504, and the system is shut down within a certain time period (system is terminated normally). Moreover, even in case of emergency such as when a shutdown cannot be executed based on the determination made in step S504 due to hang-up of processing performed by software, the power supply can be forcibly cut off by the timer unit <NUM>, thereby reliably turning off the power supply of the MFP <NUM> within a certain time period.

According to the present exemplary embodiment, when a power switch is turned off, the power supply of the MFP <NUM> is turned off within a certain time period. Meanwhile, the use of suspend enables the MFP <NUM> to be activated at high-speed in most of the normal use.

Processing by the MFP <NUM> according to the present exemplary embodiment when the power switch is turned on is described with reference to <FIG>.

<FIG> is a flowchart illustrating an example of the processing by the MFP <NUM> according to the present exemplary embodiment when the power switch unit <NUM> is turned on. The processing of this flowchart is executed by the power supply control unit <NUM> and the CPU <NUM>. Processing to be executed by the CPU <NUM> is performed by reading and executing a computer-readable program stored in the HDD unit <NUM> or the memory unit <NUM>.

When the power switch unit <NUM> is turned on, the processing of this flowchart starts.

In step S506, the power supply control unit <NUM> determines whether a current state is the suspend state. Since the power supply control unit <NUM> is arranged to be energized from the power supply system A <NUM>, the power supply control unit <NUM> can detect a turn-on of the power switch unit <NUM> if the power supply control unit <NUM> is being energized at the time of the turn-on. In this case, the power supply control unit <NUM> determines that the current state is the suspend state (YES in step S506), and then the operation proceeds to step S507.

In step S507, the power supply control unit <NUM> controls the FET <NUM> via the FET control signal <NUM>, and starts supplying power to the power supply system B <NUM>.

Subsequently, in step S508, the power supply control unit <NUM> notifies the CPU <NUM> of a resume signal <NUM>, and the CPU <NUM> executes resume processing. In step S509, when the resume processing ends, the CPU <NUM> starts receiving a job again and returns to a normal state.

The sequence of steps S507 through S509 executed when "YES" is determined in step S506 is an operation performed when the suspend processing is selected by the OFF operation of the power switch unit <NUM> (i.e., an operation normally performed when there is no job). The execution of this sequence enables the MFP <NUM> to be activated at high speed as compared to a case where the MFP <NUM> is cold booted (normal activation).

On the other hand, if the power supply control unit <NUM> is not being energized at the time of the turn-on, that is, the power supply control unit <NUM> is energized by the turn-on, the current state is a complete OFF state subsequent to a shutdown (i.e., not the suspend state) (NO in step S506), the operation proceeds to step S520. In step S520, the power supply to the power supply system A <NUM> and the power supply system B <NUM> is started.

Accordingly, such power supply causes the system to be reset, and the cold boot (normal activation) of the system begins. Particularly, in step S521, a reset of the CPU <NUM> generates a reset exception, and a boot program begins to operate (boot processing of the CPU <NUM>). The boot program enables a control program to be read from the HDD unit <NUM> into the memory unit <NUM>, and the program loaded on the memory unit <NUM> is executed, thereby activating the system.

When the system is activated, the CPU <NUM> becomes ready to receive a job. In step S522, the CPU <NUM> starts receiving a job.

The sequence of steps S520 through S522 executed when "NO" is determined in step S506 is an operation performed when shutdown processing is selected by the OFF operation of the power switch unit <NUM>. In such a case, since a state of the memory unit <NUM> is already cleared, the MFP <NUM> cannot be activated at high speed such as activation by resume processing. In this case, a job group without a job termination waiting period in step S503 illustrated in <FIG> is deleted by resetting the system, and an effect which is substantially the same as that in the conventional power off operation (<FIG>) can be achieved.

As described above, the MFP <NUM> according to the present exemplary embodiment can prevent conventional problems generated immediately after the MFP <NUM> is activated by turning on a main switch (the power switch unit <NUM>). The conventional problems include delay execution of a job instructed before the main switch was turned off in a previous operation, and a sudden occurrence of a job error. The MFP <NUM> according to the present exemplary embodiment can achieve high-speed activation by applying the memory resume technique with substantially the same operation as a main switch operation of an MFP having only a conventional shutdown function.

Accordingly, the MFP <NUM> according to the present exemplary embodiment can be activated at high speed when the ON operation of the power switch unit <NUM> is performed. Moreover, the cancel processing is performed according to the present exemplary embodiment, so that the MFP <NUM> can reduce a problem caused by a job interrupted by suspension such that the problem does not occur after activation of the MFP <NUM> even when the MFP <NUM> is activated from the suspend state by the ON operation of the power switch, the suspend state being led by the OFF operation of the power switch unit <NUM> during previous job execution.

Claim 1:
An image forming apparatus (<NUM>) comprising:
a power switch (<NUM>) configured to switch between an ON state and an OFF state in accordance with an operation of a user;
control means (<NUM>) for cancelling a job input to the image forming apparatus (<NUM>), the job being currently in execution or on standby, after the power switch (<NUM>) is switched to the OFF state; characterized in that the image forming apparatus further comprises:
power control means (<NUM>) for shifting a state of the image forming apparatus (<NUM>) to a first state if the job currently in execution or on standby is cancelled by the control means (<NUM>), and for shifting the state of the image forming apparatus (<NUM>) to a second state if the job currently in execution or on standby is not cancelled by the control means (<NUM>),
wherein the control means (<NUM>) is configured to store a state of the image forming apparatus (<NUM>) in a volatile memory (<NUM>) before the state of the image forming apparatus (<NUM>) is shifted to the first state,
wherein the first state is a suspend state in which power is supplied to the volatile memory (<NUM>) and is not supplied to the control means (<NUM>), and
wherein the second state is a state in which power is not supplied to the volatile memory (<NUM>) and is not supplied to the control means (<NUM>).