Method for controlling an image processing apparatus based on a power supply status

An image processing apparatus which is capable of recovering a normal operation thereof at high speed. A CPU 2001 that controls a printer 108 determines whether or not the printer 108 should be switched from a normal operation mode to a power saving mode. Responsive to input of a signal for causing the apparatus to recover the normal operation mode, the CPU 2001 reads out a power saving mode flag from a flip-flop circuit 11005, and when the flag indicates the apparatus has been switched to the power saving mode, reads out a main program from a SDRAM, whereas when the flag does not, reads out the main from a HDD 2004, for control of the printer 108.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2003-410611 filed Dec. 9, 2003, which are hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image processing apparatus and a control method therefor.

2. Description of the Related Art

To comply with energy-saving standards which have been becoming more and more strict, image forming apparatuses, such as printers, facsimile machines, digital copying machines, and digital multifunction machines, power supply to some component parts of the apparatus is shut down during standby to thereby largely reduce power consumption.

For example, in the case of an image forming apparatus of the type in which print data supplied from an external device, such as a personal computer, is expanded into bit data, which is supplied to a laser printer, interruption of energization of a fixing unit of the laser printer, stoppage of driving of a cooling fan, shutdown of power supply to a CPU, and so forth are carried out when the apparatus is in a power saving mode.

On the other hand, an image forming apparatuses designed to operate on a network is desired to be capable of recovering a normal operation mode from a power saving mode at high speed, when required.

Further, in recent digital multifunction machines, the programs for controlling the operation of the machine have increased in size, so that if all the programs are to be stored in a ROM, there is a fear of an increase in cost. To eliminate this inconvenience, some of the programs are stored in an area of a hard disk for storing images (see e.g. Japanese Laid-Open Patent Publication (Kokai) No. H06-067770).

In such an apparatus that stores programs in an area of a hard disk thereof, however, after the apparatus is started, the programs are once downloaded from the hard disk into a RAM, and then the CPU reads the programs from the RAM to execute the same, which makes it impossible to comply with the requirement of high-speed recovery of the normal operation mode.

As a solution to this problem, an apparatus has also been proposed which uses a sub CPU for use in a standby mode for saving energy. Under the recent situations in which competition for cost reduction has become intensified, it is not practical to provide a low-price apparatus with such a sub CPU.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image processing apparatus and a control method therefor which are capable of recovering a normal operation at high speed without increase in cost, when the apparatus is switched from a second power supply status in which power consumption is reduced to a first power supply status.

To attain the above object, in a first aspect of the present invention, there is provided an image processing apparatus that performs image processing based on image data inputted thereto, comprising a controller that controls the image processing apparatus, the controller determining whether or not the image processing apparatus should be switched from a first power supply status to a second power supply status in which power consumption of the image processing apparatus is lower than in the first power supply status, a holding unit that is responsive to a determination by the controller that the image processing apparatus should be switched from the first power supply status to the second power supply status, for holding information indicative of whether or not the image processing apparatus has been switched to the second power supply status, a first storage unit that stores control data based on which the controller controls the image processing apparatus, the first storage unit being non-volatile, and a second storage unit that stores the control data read out from the first storage unit, the second storage unit being volatile, wherein the controller is responsive to input of a signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status, for reading out the information from the holding unit, the controller reading out the control data from the second storage unit in a case where the information indicates that the image processing apparatus has been switched to the second power supply status, reading out the control data from the first storage unit in a case where the information does not indicate that the image processing apparatus has been switched to the second power supply status, and controlling the image processing apparatus based on the control data.

With the arrangement of the image processing apparatus according to the first aspect of the present invention, in responsive to input of a signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status, the controller reads out the information indicative of whether or not the image processing apparatus has been switched to the second power supply status, and when the information indicates that the image processing apparatus has been switched to the second power supply status, the controller reads out the control data from the second storage unit, which is volatile, whereas when the information does not indicate that the image processing apparatus has been switched to the second power supply status, the controller reads out the control data from the first storage unit, which is not volatile. Therefore, when the image processing apparatus is switched from the second power supply status (power saving mode) in which power consumption of the image processing apparatus is lower to the first power supply status (normal operation mode), the control data can be read from the second storage unit which is volatile and different from the first storage unit which is non-volatile, whereby recovery of the normal operation mode from the power saving mode can be carried out at high speed, and the recovery can be realized by an inexpensive image processing apparatus.

Preferably, the image processing apparatus further comprises a switching unit that is responsive to the determination by the controller that the image processing apparatus should be switched to the second power supply status, for switching a power supply status of the image processing apparatus such that power supply to the controller is shut down, and the switching unit switches the power supply status such that the power supply to the controller is resumed, in response to input of the signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status, the controller being responsive to the resumption of the power supply to the controller, for reading out the information from the holing unit, the controller reading out the control data from the second storage unit when the information indicates that the image processing apparatus has been switched to the second power supply status, reading out the control data from the first storage unit when the information does not indicate that the image processing apparatus has been switched to the second power supply status, and controlling the image processing apparatus based on the control data.

Preferably, the image processing apparatus further comprises an input unit that inputs a transition instruction from a user, for switching the image processing apparatus from the first power supply status to the second power supply status, and the controller is responsive to the input of the transition instruction from the input unit, for causing the image processing apparatus to be switched from the first power supply status to the second power supply status.

Preferably, the controller causes the image processing apparatus to be switched from the first power supply status to the second power supply status, in a case where the image processing apparatus has not been in operation for not less than a predetermined time period.

Preferably, the control data comprises a control program for controlling the image processing apparatus, and the controller controls the image processing apparatus by executing the control program.

Preferably, the holding unit erases the information indicating that the image processing apparatus has been switched to the second power supply status, in a case where the power supply status of the image processing apparatus has been switched to a power shutdown status.

Preferably, the controller is responsive to input of the signal for causing the image processing apparatus to be switched from the second power-supply status to the first power supply status, for reading out the information from the holding unit, the controller reading out the control data from the first storage unit, storing the control data in the second storage unit, and then reading out the control data from the second storage unit, for control of the image processing apparatus, in a case where the information does not indicate that the image processing apparatus has been switched to the second power supply status.

Preferably, the second storage unit is DRAM and, the controller is responsive to the determination that the image processing apparatus should be switched from the first power supply status to the second power supply status, for sending a signal for starting a self-refresh operation to the second storage unit.

Preferably, the first power supply status is a status in which image processing can be carried out, and the second power supply status is a status in which the image processing cannot be carried out.

Preferably, the image processing apparatus further comprises an input unit that inputs image data from an external unit, and the signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status is outputted in response to input of image data to the input unit from the external unit.

Preferably, the image processing apparatus further comprises a receiving unit that receives an instruction given by a user, for operating the image processing apparatus, and the signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status is outputted in response to the receiving unit having received the instruction given by the user.

More preferably, in a case where a signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status is inputted, the switching unit does not switch the power supply of the image processing apparatus such that the power supply to the controller is shut down, regardless of whether a signal for causing the image processing apparatus to be switched from the first power supply status to the second power supply status is inputted or not.

To attain the above object, in a second aspect of the present invention, there is provided a method of controlling an image processing apparatus that performs image processing based on image data inputted thereto, comprising a determining step of determining whether or not the image processing unit should be switched from a first power supply status to a second power supply status in which power consumption of the image processing apparatus is lower than in the first power supply status, a holding step of holding information indicative of whether or not the image processing apparatus has been switched to the second power supply status, in response to a determination in the determining step that the image processing apparatus should be switched from the first power supply status to the second power supply status, a reading step of reading out the information held in the holding step, in response to input of a recovery signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status, and a control step of reading out control data for controlling the image processing apparatus from a first storage unit which is non-volatile, in a case where the information read out in the reading step does not indicate that the image processing apparatus has been switched to the second power supply status, and reading out the control data from a second storage unit which is volatile, in a case where the information indicates that the image processing apparatus has been switched to the second power supply status.

Preferably, the method further comprises an output step of outputting a transition signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status, a first switching step of switching a power supply status of the image processing apparatus such that power supply to a controller that executes the control step is shut down, in response to the transition signal outputted in the output step, and a second switching step of switching the power supply status of the image processing apparatus from the second power supply status to the first power supply status such that the power supply to the controller is resumed, in response to the input of the recovery signal.

Preferably, the method further comprises an input step of inputting a transition instruction from a user, for switching the image processing apparatus from the first power supply status to the second power supply status, and the control step comprises causing the image processing apparatus to be switched from the first power supply status to the second power supply status, in response to the input of the transition instruction in the input step.

Preferably, the control step comprises causing the image processing apparatus to be switched from the first power supply status to the second power supply status, in a case where the image processing apparatus has not been in operation for not less than a predetermined time period.

Preferably, the control data comprises a control program for controlling the image processing apparatus, and the control step comprises controlling the image processing apparatus by executing the control program.

Preferably, the holding step comprises erasing the information indicating that the image processing apparatus has been switched to the second power supply status, in a case where the power supply status of the image processing apparatus has been switched to a power shutdown status.

Preferably, the control step comprises reading out the control data from the first storage unit, storing the control data in the second storage unit, and then reading out the control data from the second storage unit, for control of the image processing apparatus, in a case where the information read out in the reading step does not indicate that the image processing apparatus has been switched to the second power supply status.

Preferably, the control step comprises sending a signal for starting a self-refresh operation to the second storage unit, in response to the determination in the determining step that the image processing apparatus should be switched from the first power supply status to the second power supply status.

Preferably, the first power supply status is a status in which image processing can be carried out, and the second power supply status is a status in which the image processing cannot be carried out.

Preferably, the method further comprises an input step of inputting image data from an external unit, and the signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status is outputted in response to input of image data from the external unit in the input step.

Preferably, the method further comprises a receiving step of receiving an instruction given by a user, for operating the image processing apparatus, and the recovery signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status is outputted in response to the instruction given by the user having been received in the receiving step.

More preferably, in a case where a signal for causing the image processing apparatus to be switched from the second power supply status to the first power supply status is inputted, the power supply of the image processing apparatus is not switched such that the power supply to the controller is shut down, regardless of whether a signal for causing the image processing apparatus to be switched from the first power supply status to the second power supply status is inputted or not.

The above and other objects, features and advantages of the invention will become more apparent from the following drawings taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described in detail with reference to the drawings showing preferred embodiments thereof. In the drawings, elements and parts which are identical throughout the views are designated by identical reference numerals, and duplicate description thereof is omitted.

FIG. 1is a block diagram showing the arrangement of a printing system incorporating an image forming apparatus as an image processing apparatus according to a first embodiment of the present invention.

InFIG. 1, reference numeral101designates a network for connecting between the component elements of the printing system, and in the present embodiment, the network is assumed to be implemented by an Ethernet (registered trademark) using TCP/IP protocols.

Reference numeral102designates a network scanner that optically reads an original or the like printed on a sheet, and is provided with a network interface. The network scanner is implemented by a color scanner that reads and outputs image data of the three colors of RGB.

Reference numerals108,107, and106designate network printers each of which is equipped with a network interface, and receives print data and image data via the network interface, to actually print the received data on sheets or the like using a known printing technique, such as electrophotography. In the illustrated example, the network printer108is implemented by a monochrome digital multifunction machine, the network printer107by a color laser printer, and the network printer106by a monochrome laser printer.

Reference numeral104designates a facsimile machine which is equipped with a network interface and transmits and receives image data via a public line105. More specifically, the facsimile machine104transmits image data read by the scanner102on the network101to the public line105, outputs image data received from the public line10.5via the printers108,107, and106, transmits and receives image data in the form of files to and from a PC (Personal Computer)103via the public line105, and performs like operations.

FIG. 2is a block diagram showing the hardware configuration of a controller unit of the printer (multifunction machine)108appearing inFIG. 1. The hardware configurations of the control sections of the printers107and106are approximately the same as that shown inFIG. 2.

InFIG. 2, the controller unit (information processing apparatus)2000is connected to a scanner unit2070as an image input device and a printer unit2095as an image output device, and further to a LAN2011and a public line (WAN)2051, for controlling the input and output of image information and device information.

A CPU (Central Processing Unit)2010is a controller controlling the overall system. A RAM (volatile storage device)2002is a system work memory used for the CPU2001to operate, and also serves as an image memory for temporarily storing image data. A ROM (non-volatile storage device)2003is a boot ROM that stores a boot program of the system. A HDD (non-volatile large-capacity storage device)2004is comprised of a hard disk drive and an IDE controller, and stores system software, image data, and management information thereof.

An operating section I/F2006interfaces with an operating section (UI)2012, so as to output image data to be displayed on the operating section2012to the same and send information that the user has inputted to the operating section2012to the CPU2001. A network section2010is connected to the LAN2011to input and output information. A MODEM2050is connected to the public line2051to input and output information.

The component elements (devices) described above are connected to a system bus2007.

An image bus I/F2005is a bus bridge that connects between the system bus2007and an image bus2008that transfers image data at high speed and converts the data structure. The image bus2008is implemented by a PCI bus or an IEEE 1394 bus. Component elements (devices)2020,2030,2040,2060,2080, and2090, referred to hereinafter, are connected to the image bus2008.

The raster image process (RIP)2060expands a PDL (page-description language) code into a bit map image. The device I/F section2020connects the scanner unit2070and the printer unit2095to the controller unit2000to carry out synchronous to asynchronous conversion of image data. The scanner image processing section2080corrects, processes, and edits inputted image data. The printer image processing section2090performs correction, resolution conversion, and so forth, on image data for printing output, so as to adapt the image data to the performance of the printer unit2095. An image rotation section2030rotates image data. The image compression section2040performs various compression/decompression processes, such as a JPEG (Joint Photographic Experts Group) process for the multivalued image data, and JBIC (Joint Bi-level Image experts Group), MMR (Modified Modified READ), and MH (Modified Huffman) processes for the binary image data.

FIG. 3is a diagram showing the appearance of the scanner unit2070and the printer unit2095appearing inFIG. 2.

The scanner unit2070as the image input device illuminates an image on a sheet as an original (original sheet), and converts an optical signal obtained by scanning a CCD line sensor, not shown, over the image into an electric signal as raster image data (which is transmitted via a line2071inFIG. 2). Original sheets are set on a tray2073of an original feeder2072, and in response to an instruction for starting reading of the image, which is inputted by the user of the printer108via the operating section2012, the CPU2001(FIG. 2) delivers an instruction (which is transmitted via the line2071inFIG. 2) to the scanner unit2070, whereby the original feeder2072feeds the original sheets, one by one, and original images thereon are read.

The printer unit2095as the image output device converts raster image data (transmitted via a line2096inFIG. 2) into an image, and transfers the image onto the sheet. As the method of transferring the image, there may be employed any of electrophotography using a photosensitive drum and a photosensitive belt, an ink jet method in which ink is ejected from a minute nozzle array to directly print an image on a sheet, and so forth. The operation of the printer unit2095is started by an instruction from the CPU2001(which is transmitted via the line2096inFIG. 2). The printer unit2095has a plurality of sheet feeder stages for selection of a different sheet size or a different sheet orientation therefrom, and sheet cassettes2101,2102,2103, and2104are provided for use at the respective feeder stages. A discharge tray2111receives sheets for which printing is completed.

FIG. 4is a diagram showing the appearance of the operating section2012appearing inFIG. 2.

InFIG. 4, a LCD display section2013is comprised of a LCD (Liquid Crystal Display) and a touch panel sheet attached thereto, whereby the operating screen of the system is displayed, and when a key displayed on the screen is depressed, position information on the depressed key is sent to the CPU2001. A start key2014is operated to start the reading of an original image. In the center of the start key2014, two LEDs2018of green and red are arranged to indicate whether the start key2014is ready, by the emitted light. A stop key2015is operated to stop the running operation. An ID key2015is operated to enter the user ID of the user. A reset key2017is operated to initialize the settings set by the operating section2012.

FIG. 5is a block diagram showing the internal arrangement of the scanner image processing section2080.

InFIG. 5, an image bus I/F controller2081is connected to the image bus2008, for control of bus access sequence thereof. Further, the image bus I/F controller2081controls the devices of the scanner image processing section2080, and generates a timing signal. A filter processing section2082is implemented by a spatial filter, to perform a convolution operation. An edit section2083performs an image editing process, in which, for example, a closed area surrounded by a marker-pen line written on an original to be copied is first recognized, and then, image processing, such as shading, hatching, and negative-positive inversion, is performed on the image data within the closed area.

A zooming section2084carries out enlargement and reduction of a read image, and the size of the raster image is enlarged or reduced in the main scanning direction by executing interpolation, and the size enlargement and size reduction in the sub scanning direction is carried out by changing the speed of scanning a reading line sensor, not shown. A table conversion section2085converts the read image data as brightness data into density data using a table. A binarization section2086binarizes multivalued gray-scale image data by an error diffusion process or a screen process.

The image data having gone through the image processing is transferred onto the image bus2008again via the image bus I/F controller2081.

FIG. 6is a block diagram showing the internal arrangement of the printer image processing section2090.

InFIG. 6, an image bus I/F controller2091is connected to the image bus2008, for control of bus access sequence thereof. Further, the image bust I/F controller2091controls the devices of the scanner image processing section2090, and generates a timing signal. A resolution converting section2092converts the resolution of image data sent from the LAN2011or the public line2051into a resolution adapted to the resolution of the printer unit2095. A smoothing section2093carries out processing for smoothing jaggy portions of the image data subjected to the resolution conversion (irregularities appearing at a boundary of a white area and a black area, such as those of a slanted line).

FIG. 7is a block diagram showing the internal arrangement of the image compression section2040appearing inFIG. 2.

InFIG. 7, an image bus I/F controller2041is connected to the image bus2080for control of bus access sequence thereof. Further, the image bus I/F controller2041controls timing in which data are transmitted to an input buffer2042and received from an output buffer2045. The image bus I/F controller2041also controls an image compression processing section2043, e.g. by setting operation modes thereof.

Next, a description will be given of the procedure of an image compression process executed by the image compression section2040.

First, the CPU2001(seeFIG. 2) sets up the image bus I/F controller2041for control of image compression, via the image bus2008. The image bus I/F controller2041thus set up executes settings of the image compression processing section2043necessary for image compression (e.g. settings of MMR compression, JBIC expansion, or the like.). After these necessary settings are executed, the CPU2001permits transfer of image data to the image bus I/F controller2041. In response to the permission, the image bus I/F controller2041starts transfer of image data from the RAM2002(FIG. 2) or devices on the image bus2008.

More specifically, the image bus I/F controller2041receives image data from the RAM2002or the devices on the image bus2008, and temporarily stores the image data in the input buffer2042. Then, in response to a request of the image compression processing section2043for transfer of image data, the controller2041transfers image data from the input buffer2042to the image compression processing section2043at a constant speed. Before doing this, the input buffer2042determines whether or not image data can be transferred between the image bus I/F controller2041and the image compression processing section2043, and if it is impossible to read the image data from the image bus and write an image into the image compression processing section2043, inhibits the transfer of the image data (such control is called “handshaking control”).

The image compression processing section2043once stores the received image data in the RAM2044. This is because depending on the type of image compression processing to be carried out, the image compression necessitates several lines of data, i.e. the image compression of a first one line can be executed only after several lines of data become available.

The image data obtained through the image compression by the image compression processing section2043is immediately sent to the output buffer2045. The output buffer2045also performs the handshaking control between the image bus I/F controller2041and the image compression processing section2043, and then transfers the image data to the image bus I/F controller2041. The image bus I/F controller2041transfers the received compressed (or expanded) image data to one of the RAM2002and the devices on the image bus2008.

The above described sequence of processing operations is repeatedly carried out until a processing request is no longer is issued by the CPU2001(until processing of all the pages necessitating the image compression processing is completed), or until a stop request (generated when an error occurs during compression or expansion) is issued by the image compression processing section2043.

FIG. 8is a block diagram showing the internal arrangement of the image rotation section2030appearing inFIG. 2.

InFIG. 8, an image bus I/F controller2031is connected to the image bus2008, for control of bus access sequence thereof. Further, the image bus I/F controller2031controls an image rotation processing section2032, e.g. by setting operation modes thereof, and timing in which image data is transferred to the image rotation processing section2032.

Next, a description will be given of the procedure of an image rotation process executed by the image rotation section2030.

First, the CPU2001(inFIG. 2) sets up the image bus I/F controller2031for control of image rotation, via the image bus2008. The image bus I/F controller2031thus set up executes settings of the image rotation processing section2032necessary for image rotation (e.g. settings of image size, direction of rotation, an angle of rotation, etc.). After these necessary settings are executed, the CPU2001permits transfer of image data to the image bus I/F controller2031. In response to the permission, the image bus I/F controller2031starts transfer of image data from the RAM2002(FIG. 2) or devices on the image bus2008. Here, it is assumed that image data is transferred in units of 32 bits, and the size of image data to be rotated is 32×32 (bits). Further, when the image data is transferred onto the image bus2008as well, the transfer of the image data is carried out in units of 32 bits (image data to be processed is assumed to be binary).

To obtain 32×32-bits image data as described above, it is necessary to carry out the above 32 bits unit transfer of data 32 times, and at the same time, the image data need to be transferred using non-contiguous sender address values.FIG. 9is a diagram useful in explaining the relationship between 32×32-bits image data and non-contiguous sender address values.

The image data transferred by non-contiguous addressing is written into a RAM2033such that the image is in a position rotated through a desired angle when it is read out. More specifically, when the image is anticlockwise rotated through 90 degrees, a first transferred set of 32 bits of image data is written into the RAM2033in a Y direction as shown inFIG. 10, and read out therefrom in a X direction, whereby the image is rotated.FIG. 10is a diagram useful in explaining writing of the image data into the RAM2033on a 32 bits-by-32 bits basis.

After the rotation of a 32×32-bits data image (writing of data thereof into the RAM2033) is completed, the image rotation processing section2032reads out image data from the RAM2031in the X direction, and transfers the same to the image bus I/F controller2031.

The image bus I/F controller2031receives the image data subjected to the image rotation process, and transfers the same to one of the RAM2002and the devices on the image bus2008by contiguous addressing.

The above described sequence of processing operations is repeatedly carried out until a processing request is no longer is issued by the CPU2001(until processing of all the pages necessitating the image compression processing is completed).

FIG. 11is a block diagram showing the internal arrangement of the device I/F section2020appearing inFIG. 2.

InFIG. 11, an image bus I/F controller2021is connected to the image bus2008, for control of bus access sequence thereof. Further, the image bus IF controller2021controls the devices of the device I/F section2020, and generates a timing signal. The image bus I/F controller2021also generates control signals transmitted to the scanner unit2070and the printer unit2095provided outside thereof. A scan buffer2022temporarily stores image data sent from the scanner unit2070, and outputs the same in synchronism with the operation of the image bus2080. A serial-parallel/parallel-serial conversion section2023sequentially arranges or decomposes the image data stored in the scan buffer2022and converts the same into image data having a data width which can be transmitted through the image bus2008. A parallel-serial and serial-parallel conversion section2024decomposes or sequentially arranges the image data transferred from the image bus2008, and converts the same into image data having a data width which can be stored in a print buffer2025. The print buffer2025temporarily stores the image data sent from the image bus2008, and outputs the same to the printer unit2095in synchronism with the operation of the printer unit2095.

Next, a description will be given of the operation of the device I/F section2020when the scanner unit2070performs image scanning.

The device I/F section2020stores the image data sent from the scanner unit2070in the scanner buffer2022in synchronism with the timing signal sent from the scanner unit2070. Then, if the image bus2008is implemented by a PCI bus, when not less than 32 bits of image data have entered the scan buffer2022, 32 bits of image data are sent according to the first-in first-out method from the scan buffer2022to the serial-parallel/parallel-serial conversion section2023, wherein the data is converted into 32-bit image data, and then transmitted to the image bus2008via the image bus I/F controller2021. On the other hand, if the image bus2008is implemented by an IEEE1394 bus, the image data in the scan buffer2022is sent according to the first-in first-out method from the scan buffer2022to the serial-parallel/parallel-serial conversion section2023, wherein the data is converted into serial image data, and transferred to the image bus2009via the image bus I/F controller2021.

Next, a description will be given of the operation of the device I/F section2020when image printing is performed.

When the image bus2008is implemented by a PCI bus, 32-bit image data transmitted from the image bus2008is received by the image bus I/F controller2021, and sent to the parallel-serial/serial-parallel conversion section2024, wherein the image data is converted into image data adapted to the input data bit number of the printer unit2095and stored in the print buffer2025. On the other hand, if the image bus2008is implemented by an IEEE1394 bus, the serial image data sent from the image bus2008is received by the image bus I/F controller2021, and sent to the parallel-serial/serial-parallel conversion section2024, wherein the image data is converted into image data adapted to the input data bit number of the printer unit2095and stored in the print buffer2025. Then, the image is sent from the print buffer2025in synchronism with the timing signal sent from the printer2025according to the first-in first-out method, to the printer unit2095.

FIG. 12is a block diagram showing the software configuration of a control section of the printer108appearing inFIG. 1. The software configuration of the respective control sections of the printers107and106are also basically approximately the same as that of the printer108shown inFIG. 12.

InFIG. 12, reference numeral1501designates a UI (User Interface) module, and interfaces between the printer108and a user when the user carries out various processing and setting operations. This module transmits information inputted to the same by user's operations, to various modules, referred to hereinafter, to make requests for processing, perform settings of data, etc.

Reference numeral1502designates an address book, i.e. a database which manages destinations of transfer of (i.e. recipients of) data, those of communications, and the like. Data is added to, deleted from, and acquired from the address book1502in response to instructions from the UI module1501, and the address book1502is used for giving information on a destination of data transfer or communication to each of modules, described hereinafter.

Reference numeral1503designates a Web server module used for notifying the management information on the printer108to a Web client in response to a request made by the Web client. The management information is read from the printer108via a control API1518, referred to hereinafter, and notified to the Web client via a HTTP module1512, a TCP/IP module1516, and a network driver1517.

Reference numeral1504designates a universal send module which is responsible for distribution of data. The universal send module150distributes data designated by the user via the UI module1501to destinations of communication (output) also designated by the user. Further, when the user gives an instruction to generate distribution data by making use of the scanner function of the present printer108, the universal send module150causes the scanner unit2070to operate, via the control API1518, to thereby generate data.

Reference numeral1505designates a P550 module that is executed when one or more printers are designated as output destinations by the universal send module150.

Reference numeral1506designates an E-mail module that is executed when one or more E-mail addresses are designated as communicating destinations by the universal send module150.

Reference numeral1507designates a DB module that is executed when one or more databases are designated as output destinations by the universal send module150.

Reference numeral1508designates a DP module that is executed when one or more multifunction printers similar to the present printer108are designated as output destinations by the universal send module150.

Reference numeral1509designates a RCS (Remote-Copy-Scan) module that uses the scanner function of the present printer108, and performs a process equivalent to that performed by the scanner function realized singly by the present printer108, with one or more output destinations set to other multifunction printers connected to the present printer via the network or the like.

Reference numeral1510designates a RCP (Remote-Copy-Print) module that uses the printer function of the present printer108, and performs a process equivalent to that performed by the printer function realized singly by the present printer108, with one or more output destination set to other multifunction printers connected to the present printer via the network or the like.

Reference numeral1511designates a WPP (Web-Pull-Print) module that reads out information of various Web pages on the Internet or an intranet, and performs printing.

Reference numeral1512designates a HTTP (Hypertext Transfer Protocol) module that is used by HTTP for communication, and provides a communication capability to the aforementioned Web server module1503and the WPP module1511, together with a TCP/IP module1516, described hereinafter.

Reference numeral1513designates a LPR module that provides a communication capability to the aforementioned P550 module1505of the universal send module150, together with the TCP/IP module1516.

Reference numeral1514designates a SMTP module that provides a communication capability to the aforementioned E-mail module1508, together with the TCP/IP module1516.

Reference numeral1515designates a SLM (Salutation-Manager) module that provides a communication capability to the aforementioned DB module1507, DP module1508, RCS module1509, and RCP module1510of the universal send module150, together with the TCP/IP module1516.

Reference module1516designates the TCP/IP module that provides the communication capability to the aforementioned various modules, together with a network driver1517, described next.

Reference numeral1517designates the network driver that controls devices physically connected to the network.

Reference numeral1518designates the control API that provides upstream modules, such as the universal send module150, with an interface for interfacing between the upstream modules and downstream modules, such as a job manager1519, for alleviating the mutual dependency between the upstream modules and the downstream modules to enhance compatibility or versatility of each module.

Reference numeral1519designates the job manager that interprets a process designated by each of the aforementioned modules via the control API1518, to give an instruction to each of modules, referred to hereinafter. Further, the present module carries out the collective management of hardware-based processes executed by the present printer108.

Reference numeral1520designates a CODEC manager that manages and controls various kinds of compression and expansion processes designated by the job manager1519.

Reference numeral1521designates a FBE encoder that compresses data read by the scanning process executed by the job manager1519and a scan manager1524, using a FBE format.

Reference numeral1522designates a JPEG-CODEC that performs JPEG compression of read data and JPEG expansion of print data, during execution of the scanning process by the job manager1519and the scan manager1524, and during execution of the printing process by a print manager1526.

Reference numeral1523designates a MMR-CODEC that performs MMR compression of read data and MMR expansion of print data, during execution of the scanning process by the job manager1519and the scan manager1524, and during execution of the printing process by the print manager1526.

Reference numeral1524designates the scan manager that manages and controls the scanning process designated by the job manager1519.

Reference numeral1525designates a SCSI driver that performs communications between the scan manager1524and the scanner unit2070to which the printer108is internally connected.

Reference numeral1526designates the print manager that manages and controls the printing process designated by the job manager1519.

Reference numeral1527designates an engine I/F driver that provides an interface between the print manager1526and the printer unit2095.

Reference numeral1528designates a parallel port driver (Parallel) that provides an interface between the WPP module1511and an output device, not shown, when the WPP module1511outputs data to the output device via a parallel port.

Next, a description will be given of applications installed in the printer108, with reference toFIG. 13.

FIG. 13is a diagram showing the relationship between the applications installed in the printer108and communication counterpart devices, which are associated respectively with the applications. InFIG. 13, the applications installed in the printer108are shown on the left-hand side, while the communication counterpart devices are shown on the right-hand side.

InFIG. 13, reference numeral4050is a UI application which includes an address book4051.

Reference numeral4100designates a remote copy application (sender side).

Reference numeral4150designates a broadcasting application (sender side).

Reference numeral4250designates a Web server application.

Reference numeral4300designates a printer apparatus as a recipient associated with the remote copy application4100, for performing printing.

Reference numeral4350designates a general printer device that receives image data transmitted from the broadcasting application4150, for performing printing.

Reference numeral4400designates a printer apparatus that receives image data transmitted from the broadcasting application4150, for performing printing. This printer apparatus4400is a recipient (printing side) of the remote printing.

Reference numeral4450designates a server apparatus, more specifically a notes servers, that receives image data transmitted from the broadcasting application4150, for storage therein.

Reference numeral4500designates a server apparatus that receives image data transmitted from the broadcasting application4150, and stores the same as binary data.

Reference numeral4550designates a mail server that receives image data transmitted from the broadcasting application4150, for storage therein.

Reference numeral4600designates a DB server that receives image data transmitted from the broadcasting application4150, and stores the same as multivalued data.

Reference numeral4650designates a Web server that receives information contents transmitted from the WPP application4200, for storage therein.

Reference numeral4700designates a Web browser that accesses the Web server application4250.

The UI application4050corresponds to the aforementioned UI module1501, and the address book4051corresponds to the aforementioned address book1502.

The address book4051is stored in a non-volatile storage device (non-volatile memory, hard disk, or the like) of the printer108, and contains entries of properties of a plurality of communication counterpart devices connected to the network. For example, the entries include the following:

Formal name and alias name of each apparatus or device

Network address of the same

Network protocol(s) compatible with the same

Document format(s) compatible with the same

Compression type(s) compatible with the same

Image resolution(s) compatible with the same

Size(s) of feedable sheets and information on feeder stage(s), when the apparatus is a printer apparatus,

Name of a folder that can store documents when the apparatus is a server (computer) apparatus

Applications described hereinafter each determine the properties of a recipient (counterpart apparatus or device) from the information of entries of the address book4051. Further, the address book4051can be edited, and information collected and stored in a server computer on the network may be downloaded for use as the information of entries. Further, the information of entries may be collected by directly accessing each recipient (counterpart apparatus or device).

The remote copy application4100acquires information of resolutions compatible with an apparatus or device designated as a recipient from the address book4051, and according to the information, reads binary image data using the scanner unit2070, compresses the image data by MMR compression, converts the compressed image into TIFF (Tagged Image File Format) data, and sends the TIFF data to the printer apparatus4300on the network by SLM, which is a kind of network protocol including device control information called Salutation Manager (or Smart Link Manager), though not described in detail here.

As is distinct from the remote copy application4100, the broadcasting application4150sends image data to a plurality of recipients, per each image scanning operation. The recipients are not limited to printer apparatuses, but this broadcasting application4150can also directly send image data to so-called server computers.

Hereafter, a description will be given on a recipient type-by-recipient type basis.

When determining with reference to the address book4051that the recipient apparatus is compatible with LPD (Line Printer Daemon) as a network printer protocol, and LIPS as a printer control command, the broadcasting application4150also performs reading of image data according to an image resolution also acquired by referring to the address book4051, compresses the image data using FBE (First Binary Encoding), further converts the compressed image data into LIPS code data, and sends the resulting data to the recipient printer apparatus4350by LPR as a network printer protocol.

When determining with reference to the address book4051that the recipient apparatuses are server apparatuses compatible with SLM, the broadcasting application4150further refers to the address book4051to determine server addresses and designated folders of the respective servers, and similarly to the remote copy application4100, reads binary image data using the scanner unit2070, compresses the image data by MMR compression, converts the compressed image into TIFF data, sends the TIFF data to the server apparatuses4450and4500on the network by SLM, for storage in specified folders.

When determining with reference to the address book4051that the recipient apparatus is a server apparatus compatible with multivalued data compressed by JPEG, the broadcasting application4150compresses the read multivalued image data by JPEG, similarly to the binary image, converts the compressed image into JFIF data, sends the JFIF data to the server apparatus4600on the network by SLM, for storage in a specified folder.

Further, when determining with reference to the address book4051that the recipient apparatus is a mail server, the broadcasting application4150further refers to the address book4051to acquire a mail address, reads binary image data using the scanner unit2070, compresses the binary image data by MMR compression, converts the compressed image into TIFF data, sends the TIFF data to the mail server4550using SMTP (Simple Mail Transfer Protocol). The distribution of the image data is executed thereafter by the mail server4550.

The WPP application4200and Web server application4250are no directly concerned with the present embodiment, and therefore description thereof is omitted.

Incidentally, the controller unit2000(seeFIG. 2) defines databases that store values set to jobs, functions of devices (scanner unit2070, printer unit2095, etc.), statuses, billing information, and so forth, in the form of data conforming to the control API1518, and interfaces with the databases, as a Device Information Service (hereinafter referred to as “the DIS”).

FIG. 14is a diagram which is useful in explaining exchange of information between the DIS7102, the job manager1519, the scan manager1524, and the print manager1526.

Basically, dynamic information, such as job start commands, is directly issued from the job manager1519to the scan manager1524and the print manager1526, whereas static information, such as the functions of devices and contents of jobs, is sent from the job manager1519via the DIS7102to the scan manager1524and the print manager1526. Static and dynamic information from the scan manager1524and the print manager1526, and events are transmitted via the DIS7102to the job manager1519.

When the setting of data to or the acquisition of information from each database of the DIS7102is executed from the scan manager1524and the print manager1526, since the data format of the database of the DIS7102conforms to the control API1518, there is carried out processing for conversion between the data format conforming to the control API and a data format which can be dealt with by the scan manager1524and the print manager1526, respectively. For example, when the scan manager1524and the print manager1526set respective status data to a database in the DIS7102, the status data, which are peculiar to the respective devices, are interpreted and converted to compatible data defined based on the control API1518, and then written into the database.

When the setting of data to or the acquisition of information from any of the databases in the DIS7102is executed from the job manager1519, no data conversion is performed between the job manager1519and the DIS7102.

Further, the DIS7102updates event data based on information of various events notified from the scan manager1524and the print manager1526.

FIG. 15is a diagram useful in explaining various databases stored in the DIS7102. InFIG. 15, rectangular blocks with rounded corners represent individual databases (DB). Now, a description will be given of each database.

Reference numeral7201designates a supervisor DB, which stores statuses and user information on all the counterpart apparatuses. Information which needs to be backed up, such as user IDs and passwords, is stored in a non-volatile storage device, such as a hard disk and a back-up memory.

Reference numeral7202designates a scan component DB, and7203a print component DB. These component DBs are provided in association with the counterpart apparatuses. For example, if the counterpart apparatuses are printers alone, only the print component DB is provided. Further, if the counterpart apparatuses, a FAX component DB is provided, though not shown. When the component DBs are initialized, the scan manager1524, the print manager1526, and so forth, which are associated with the component DBs, respectively, set the functions and statues of the apparatuses to the respective component DBs.

Reference numeral7204designates a scan job service DB,7205a print job service DB. When these job service DBs are initialized, similarly to the component DBs, the scan manager1524, the print manager, and so forth, which are associated with the job service DBs, respectively, set the functions that can be used by the apparatuses, and support statuses of the apparatuses, to the respective component DBs.

Next, a description will be given of the JOB DBs and the document DBs.

Reference numeral7206designates a scan job DB,7207a print job DB,7208a scan document DB, and7209a print document DB.

The job DBs and the document DBs are dynamically secured and initialized by the job manager1519whenever a job and a document involved in the job are generated to thereby set the necessary items to the DBs. Before starting processing of a job, the scan manager1524, the print manager1526, and so forth read out the necessary items for the processing, from the job DB and the document DB associated therewith to start the job. Then, after completion of the job, the DB associated with the job and the document involved in the job are set free. One job has at least one document, and therefore, a plurality of document DBs are sometimes secured for a certain job.

Reference numeral7211designates an event table DB that stores event information notified by the scan manager1524, the print manager1526, etc., and reference numeral7210a soft counter DB for recording the number of times of scanning, and the number of times of printing.

The events notified by the scan manager1524include a state transition of each component, completion of a scanning operation, and various errors, and the events notified by the print manager1526include a state transition of each component, completion of a printing operation, jamming, an open state of a feeder cassette, and so forth, with event IDs being defined in advance for discriminating between the events.

When an event is issued from the scan manager1524or the print manager1526, the DIS7102registers the event ID of the issued event, and detailed data accompanying the event, if necessary, in the event table DB7211. Further, when cancellation of an event is notified by the scan manager1524or the print manager1526, event data of the event which has been designated to be canceled is deleted from the event table DB7211.

When polling of an event is performed by the job manager1519, the DIS7102refers to the event table DB7211, and sends back the event ID of an event currently occurring, and data of details accompanying the event, if necessary, to the job manager1519, whereas if no event is occurring, information to that effect is sent back to the job manager1519.

Further, when an event of completion of a scanning operation or an event of completion of a printing operation is notified, the counter value of a user who performed scanning or printing is updated by software. The counter value updated by software is written into a non-volatile storage device, such as a back-up memory device and a hard disk, whenever the value is updated, so as to prevent the value from being lost due to unexpected shutdown of the power.

Next, a detailed description will be given of the scanning operation.

FIG. 16is a block diagram showing the hardware configuration of a control section provided within the scanner unit2070appearing inFIG. 2, for controlling the operation of the scanner unit2070.

InFIG. 16, a CPU8101, a memory8102, a SCSI controller8103, an image compression and expansion board (CODEC)8104, and an IDE controller8108are connected to a PCI bus8105. Connected to the SCSI controller8103is a scanner section8107via a SCSI interface cable8106, and the SCSI controller8103provides an interface for connecting the scanner section8107to the PCI bus8105. Further, connected to the IDE controller8108is an IDE hard disk8110via an IDE cable8109.

FIG. 17is a block diagram showing the software configuration of software programs stored in the memory8102and executed by the CPU8101, for controlling the operation of the scanner unit2070.

A job manager8201has a function of classifying and storing requests at the application level. A DIS8202stores parameters necessary for a scanning operation at the application level. Requests from applications are stored in the memory8102appearing inFIG. 16.

A scan operation management section8203acquires information necessary for performing scanning from the job manager8201and the DIS8202. More specifically, the scan operation management section8203receives table data comprised of a job number and a document number from the job manager8201, and then scan parameters corresponding to the table data from the DIS8202. Based on the scan parameters as scanning requirements of the application, the scanning operation is carried out.

FIG. 18is a diagram showing the format of the table data that the scan operation management section8203receives from the job manager8201. The table data is comprised of a job number8303and a document number8304.FIG. 19is a diagram useful in explaining the scan parameters stored in the DIS8202. The scan parameters include a job number8305, document numbers8306, image file types8307, scanned image properties8308, and scanned image compression formats8309.

Referring again toFIG. 17, the scan operation management section8203sends the scan parameters acquired from the DIS8202to a scan sequence control section8204in the order of document numbers. The scan sequence control section8204having received the scan parameters controls a SCSI control section8207according to the contents of the scanned image properties8308. This causes the SCSI controller8103appearing inFIG. 16to operate, whereby a SCSI control command is sent to the scanner section8107via the SCSI interface cable6, to thereby perform scanning.

Image data obtained by the scanning is sent from the scanner section8107inFIG. 16to the SCSI controller8103via the SCSI interface cable6, and stored in the memory8102via the PCI bus8105.

At a time point the scanning is completed and the image data is stored in the memory8102, the scan sequence control section8204makes a request to a compression and expansion control section8205so as to compress the scanned image stored in the memory8102according to the contents of a designated one of the scanned image compression formats8309of the scan parameters. Upon reception of the request, the compression and expansion control section8205performs compression of the scanned image using the CODEC8104shown inFIG. 16according to the designated scanned image compression format8309. The compression and expansion control section8205stores the compressed image data in the memory8102via the PCI bus8105.

At a time point the compression and expansion control section8205compresses the scanned image according to the designated scanned image compression format8309and stores the compressed scanned image in the memory8102, the scan sequence control section8204forms the compressed scanned image data stored in the memory8102into a file according to a designated one of the image file types8307of the scan parameters. More specifically, the scan sequence control section8204requests the file system8206to form the compressed scanned image data into a file according to a file format of the designated image file type8307of the scan parameters.

The file system8206forms the compressed image data stored in the memory8102into a file according to the image file type8307, and transfers the file to the IDE controller8108via the PCI bus8105shown inFIG. 16. The file of the image data is further transferred to the IDE hard disk8110via the IDE cable8109, and stored in the IDE hard disk8110. At a time point the file system8206stores the file of the image data in the IDE hard disk8110, the scan sequence control section8204sends back to the scan operation management section8203a scan completion notification to the effect that processing of one page of an original on the scanner section8107is completed.

At this time point, if there remains an original yet to be scanned on the scanner section8107, and at the same time a scan request is sent from the job manager8201, the scan operation management section8203makes a request again to the scan sequence control section8204using the scan parameters stored in the DIS8202to perform a scan operation.

On the other hand, if there remains no original yet to be scanned on the scanner section8107, or no scan request is sent from the job manager8201, the scan operation management section8203judges that the scan operation is completed, and issues a scan completion notification to the job manager8201.

Next, a detailed description will be given of the printing operation.

FIG. 20is a block diagram showing the hardware configuration of a control section provided within the printer unit2095appearing inFIG. 2, for controlling the operation of the printer unit2095.

As shown inFIG. 20, a CPU9001, a memory9002, an image compression expansion board (CODEC)9004, and an engine I/F board9003are connected to a PCI bus9005. A printer section9007is connected to the engine I/F board9003via an engine interface cable9006.

The engine I/F board9003has a DPRAM provided therein, and performs, via the DPRAM, setting of parameters to the printer section9007and reading of status information from the same as well as sending and receiving control commands to and from the same. Further, the engine I/F board9003has a video controller and transmits image data loaded on the PCI bus9005to the printer section9007via the engine interface cable9006in synchronism with a signal VCLK (Video Clock) and a signal HSYNC received from the printer section9007via the engine interface cable9006.

FIG. 21is a timing diagram showing the relationship between the signal VCLK (source signal), signals HSYNC (source and printing process signals), and source and print image data (video signals).

As shown inFIG. 21, the signal VCLK is constantly generated, and the printing process signal HSYNC is generated in synchronism with the start of printing one line of image data at the printer section9007. The video controller reads out the print image data from the source image data in an amount corresponding to a preset image width (WIDTH) from the memory9002, and delivers the print image data as the video signal to the printer section9007via the engine interface cable9006. After repeating this operation for a designated number of lines (LINES), a command IMAGE_END, referred to hereinafter, is generated.

As described hereinbefore, when a print job is instructed from an application program operating on the CPU2001to the control API1518appearing inFIG. 12, the control API1518passes the print job to the job manager1519. The job manager1519stores the settings of the job in the DIS7102inFIG. 14, and instructs the start of the job to the print manager1526. Upon receipt of the job, the print manager1526reads out information necessary for execution of the job from the DIS7102, and causes the engine I/F board9003and the printer section9007appearing inFIG. 20to execute printing.

A specific example of the above operation will be described hereinbelow.FIG. 22shows print parameters set in the engine I/F board, andFIG. 23shows the control commands and status commands transmitted and received between the printer section9007and the engine I/F board9003, both the parameters and the commands being stored in the DPRAM within the engine I/F board9003.

Hereafter, for simplicity of description, it is assumed that a print job executed here is defined by the conditions of non-compression, a letter size (11 inches×8.5 inches), binary image, and one copy of two pages for printing, with a resolution of the printer section9007being set to 600 dpi.

First, the print manager1526having received the print job calculates the number of bytes WIDTH in the transverse direction of the print image (8.5 inches in this case).

Next, the number of lines LINES in the longitudinal direction is calculated.

The calculated values and a given address SOURCE in the memory9002at a location where image data of a first page is stored are stored in respective associated portions of the print parameters shown inFIG. 22and stored in the DPRAM. At this time point, the engine I/F board9003is ready for outputting the image, but since the printing process signal HSYNC has not been supplied from the printer section9007yet (the signal VCLK has already been supplied), print image data is not outputted to the printer section9007.

Next, the print manager1526writes an output number of 1 in an area within the DPRAM corresponding to a command BookNo (seeFIG. 23). Then, a request for feeding an output sheet for the first page (i.e. command FEED_REQ) is issued, and a command IMAGE_REQ sent from the printer section9007is awaited. Upon supply of the command IMAGE_REQ from the printer section9007, a command IMAGE_START is delivered to the printer section9007. When the printer section9007, upon receipt of the command IMGE_START, outputs the printing process signal HSYNC, the engine I/F board9003, which has been waiting for the supply of the printing process signal HSYNC, delivers the image data to the printer section9007, to thereby start printing.

Then, when detecting the trailing end of the output sheet, the printer section9007delivers the command IMAGE_END, and when the output sheet is discharged, the same delivers a command SHEET_OUT. After receiving the command IMAGE_END for the first page, the print manager1526sets the setting values WIDTH, LINES, and SOURCE for a second page to the engine I/F board9003, and delivers the command FEED_REQ to the printer section9007, to wait for the supply of the command IMAGE_REQ. The print manager1526, upon receipt of the command IMAGE_REQ for the second page from the printer section9007, performs the same operation as performed for the first page.

Next, a description will be given of high-speed recovery from a power saving mode according to the present invention.

FIGS. 24 to 26are diagrams showing a main part and a circuit necessary for the power saving mode operation of the controller unit2000. Solid lines and broken lines inFIGS. 24 to 26are for discrimination between components driven by a first power supply system and those driven by a second power supply system. The first power supply system supplies power (continues to be ON) even after the printer108has been switched to the power saving mode, and the second power supply system is separated from the first power supply system to stop supply of power (turns OFF) when the printer108has shifted to the power saving mode.

InFIGS. 24 to 26, a FET11001serves to disconnect the first power supply system from the second power supply system. When the printer108has been switched to the power saving mode, the second power supply system is disconnected from the first power supply system, to inhibit the power from being supplied to other parts than the main part of the controller unit2000(which at least needs to be supplied with power), whereby the wasteful standby-power is reduced. Although not shown inFIGS. 24 to 26, the ROM2003appearing inFIG. 2is supplied with power from the first power supply system, and the HDD2004is supplied with power from the second power supply system.

The present invention is characterized in that the CPU2001which generally consumes higher power than the other components of the controller unit2000is supplied with power from the second power supply system, whereby the CPU2001is on standby during the power saving mode with no power being supplied thereto, and at the same time, when it is necessary to recover the power due to an external cause, the controller unit2000can recover the power supply state by itself.

More specifically, the printer108has the multiple functions as described hereinabove, and accordingly extensive software is required for controlling the functions. To avoid an increase in the total cost of the controller unit2000due to the software being extensive, only information (boot program) necessary for booting the system is stored in the ROM2003shown inFIG. 2, and on the other hand, software for causing the printer108to execute main operations is stored in the HDD2004which is mainly used to store image information. As a result, when the main power is turned on as usual, a main program, which is large in size and stored in the HDD2004, is first downloaded into the RAM2002(SDRAM2002in the example illustrated inFIGS. 24 to 26), and then executed. In this case, it takes time before the main program starts to be executed, and therefore there is a fear that when executing the printing process based on data transmitted by network communication, facsimile communication, or the like, the communication may time out.

Further, in recent digital multifunction machines, a short required starting time is often featured as one of selling points in the specifications thereof, and from this viewpoint as well, it is necessary to provide a means for reducing the required starting time for the start of the system. As a solution to this problem, the present invention provides an inexpensive logic circuit shown inFIGS. 24 to 26.

FIG. 24is a diagram showing the arrangement of the main part and the circuit for the power saving mode operation of the controller unit, in which a sequence of control operations of the controller unit during transition to the power saving mode are explicitly shown.

As shown inFIG. 24, the CPU2001has a general output port GP0<1> to which is connected a clock input terminal of a flip-flop circuit (FF)11005, and a general output port GP0<0> to which is connected a PR terminal of a flip-flop circuit (FF)11002via a buffer11007. The PR terminal of the flip-flop circuit (FF)11002is supplied with 3.3 V voltage from the first power supply system. Connected to a clock input terminal of the flip-flop circuit (FF)11002is an output terminal of a logic OR gate11004, and connected to a CLR terminal of the same is an output terminal of a reset IC11003. Further, a D terminal of the flip-flop circuit (FF)11002is grounded, and a Q terminal of the same is connected to agate terminal of the FET11001. The FET11001turns off when a high-level signal is inputted to the gate terminal thereof to shut down the second power supply system.

An output terminal of the reset IC11003is connected to a CLR terminal of the flip-flop circuit (FF)11005. The reset IC11003monitors the first power supply system, and when the printer108starts, i.e. when the first power supply system turns on from an off state (in which the main power of the printer108is off), the reset IC11003sends a reset signal (reset) to the CLR terminals of the flip-flop circuits (FF)11002and11005to thereby cause Q terminals of the same to go low.

A D terminal of the flip-flow circuit (FF)11005is supplied with 3.3 V voltage from the first power supply system, and a Q terminal of the same is connected to a general input port GPI<0> of the CPU2001via a buffer11008.

The logic OR gate11004has input terminals thereof supplied with a power ON signal from the operating section2012(UI) inFIG. 2, a power ON signal received together with a print request from the network section2010inFIG. 2, and a power ON signal received together with a print request (facsimile transmission) from the MODEM2050inFIG. 2, while the output terminal of the logic OR gate11004is not only connected to the clock input terminal of the flip-flop circuit (FF)11002as mentioned above, but also connected to an interrupt terminal INTERRUPT of the CPU2001via a buffer11006.

It should be noted that the buffers11006to1108are driven by the second power supply system, and when the printer108is switched to the power saving mode, the buffers11006to11008serve to block the flow of electric current from the first power supply system.

Next, a description will be given of a flow of control of the controller unit2000when the printer.108is switched to the power saving mode.

(1) When the user gives an instruction to enter the power saving mode via the operating section2012inFIG. 2, or when the printer108has not been in operation for not less than a predetermined time period, the CPU2001determines that the conditions for entering the power saving mode have been satisfied, and delivers a self-refresh command to the SDRAM2002to cause the same to preserve the main program.

(2) Then, the CPU2001causes the general output port GP0<1> to change its signal level from low (L) to high (H), whereby the output from the Q terminal of the flip-flop circuit (FF) becomes 1 (high), whereby a flag is set. The flip-flop circuit (FF)11005is driven by the first power supply system, as mentioned above, and therefore, even after entering the power saving mode, the value of this flag is preserved.

(3) Next, the CPU2001causes the signal level of the output from the general output port GP0<0> to be changed to thereby preset the signal level of the output from the Q terminal of the flip-flop circuit (FF)11002to a high (H) level. This turns off the FET11001to shut down the power from the second power supply system whereby the printer108enters the power saving mode. The power supply to the CPU2001is interrupted.

In this way, the transition to the power saving mode is controlled by the above-described sequence of control operations of the controller unit2000.

FIG. 25is a diagram showing the arrangement of the main part and the circuit for the power saving mode operation of the controller unit2000, in which a sequence of control operations of the controller unit2000during recovery from the power saving mode are explicitly shown. Hereafter, a description will be given of the sequence of control operations executed by the controller unit2000when the printer108recovers from the power saving mode.

(1) While the printer108is on standby in the power saving mode, if there occurs an event demanding recovery of the printer108from the power saving mode, so that the power ON signal is inputted to the logic OR gate11004, the power ON signal at a high level is inputted to the interrupt terminal INTERRUPT of the CPU2001.

(2) On the other hand, the above power ON signal is also sent to the clock input terminal of the flip-flop circuit (FF)11002, causing the signal level of the Q terminal output of the flip-flop circuit (FF)11002to go low (L). This turns on the FET11001to activate the second power supply system to start recovery from the power saving mode.

(3) The CPU2001thus supplied with the power from the second power supply system is booted to execute the boot program stored in the ROM2003. The execution of the boot program causes the CPU2001to take in the output from the Q terminal of the flip-flop circuit (FF)11005via the general input port GPI <0>, namely, refers to the value of the flag set by the flip-flop circuit (FF)11005.

(4) Since the value of the flag is 1, the CPU2001determines that the printer108is in the state recovered from the power saving mode. In this state, the main program is preserved in the SDRAM2002(stored when entering the power saving mode), and hence the CPU2001starts to execute the main program stored in the SDRAM2002. Since the power ON signal at a high level (H) is inputted to the interrupt terminal INTERRUPT of the CPU2001as mentioned above, the CPU2001, which is executing the main program, recognizes that some external factor has occurred which causes recovery of the printer108from the power saving mode, and determines which of turn-on of the power through operation of the operating section2012(UI), a print request from the network section2010, and a print request (facsimile transmission) from the MODEM2050forms the factor, and carry out control according to the determined factor after the activation thereof.

FIG. 26is a diagram showing the arrangement of the main part and the circuit for the power saving mode operation of the controller unit, in which a sequence of control operations of the controller unit2000performed when the user turns on the main power supply from an OFF state thereof to start the printer108are explicitly shown.

(1) When the main power supply to the printer108is turned on, the reset IC11003outputs the reset signal (reset) to the CLR terminal of the flip-flop circuit (FF)11005to clear the flag held by the flip-flop circuit (FF)11005to 0.

(2) Further, the reset IC1103outputs the reset signal (reset) to the CLR terminal of the flip-flop circuit (FF)11002to clear the output from the Q output terminal of the flip-flop circuit (FF)11002, i.e. cause the same to go low. This turns on the FET110001to activate the second power supply system, and the CPU2001is booted to execute the boot program stored in the ROM2003.

(3) The CPU2001having executed the boot program refers to the flag stored in the flip-flop circuit (FF)11005. Since the value of the flag is 0 at this time, the CPU2001determines that the main power has been turned on from the off state, and in this case, downloads the main program from the HDD2004inFIG. 2into the SDRAM2002, and executes the main program.

Now, a description will be given of the control operations executed by the CPU2001of the controller unit2000as shown inFIGS. 24 to 26, by also referring toFIG. 30.

In a step S3001, the CPU2001determines whether the printer108as the image processing apparatus should be switched from a state in which it is supplied with a normal power (normal operating mode) to a state in which it is supplied with a lower power (power saving mode) than the normal power. More specifically, when the user gives an instruction for causing the printer108to enter the power saving mode via the operating section2012, or when the printer108has not been in operation for not less than a predetermined time period (when no print data has been received by the network section2010or when no facsimile data has been received by the MODEM2050), the CPU2001determines that the printer108should be switched to the power saving mode, and the present process proceeds to a step S3002.

In the step S3002, to cause a signal indicative of a the printer108having entered the power saving mode to be held by the flip-flop circuit11005, the CPU2001causes the signal level of the general output port GP0<1> to change from low (L) to high (H). This causes the signal level of the flip-flop circuit11005to become 1 (high) to thereby set the power saving mode flag.

In a step S3003, the CPU2001outputs a high-level signal (H) as a power saving mode transition signal from the general output port GP0<0> to the Q terminal of the flip-flop circuit11002. This turns off the FET11001to shut down the power from the second power supply system to cause the printer108to enter the power saving mode. By shutting down the power from the second power supply system, the power supply to the CPU2001is interrupted.

In a step S3004, the CPU2001reads in the flag of the flip-flop circuit11005via the general input port GP1<0>. Although the power supply to the CPU2001is interrupted in the step S3003, when the step S3004is executed, the power supply thereto has been resumed. This is because the FET11001turns on the second power supply system due to input of a recovery causing signal which causes recovery from the power saving mode from the logic OR gate11004(a signal (power on (UI)) indicative of a user's input to the operating section2012), a signal (power on (network)) indicative of reception of print data by the network section2010, or a signal (power on (FAX)) indicative of reception of facsimile data by the MODEM2050to the flip-flop circuit11002, so that the power supply to the CPU2001is resumed thereafter.

In a step S3005, the CPU2001determines from the flag read in from the general input port GPI<0> whether or not the power saving mode flag has been set in the flip-flop circuit11005. If the power saving mode flag has been set, the present process proceeds to a step S3006, whereas if not, the same proceeds to a step S3007.

In the step S3006, since the power saving mode flag has been set, the CPU2001reads out the main program from the SDRAM2002for control of the printer108.

On the other hand, in the step S3007, since the power saving mode flag has not been set, the CPU2001reads out the main program from the HDD2004for control of the printer108to download the same into the SDRAM2002, and then reads out the main program from the SDRAM2002.

In a step S3008, the CPU2001controls the printer108by executing the main program read from the SDRAM2002in the step S3006or the same read from the HDD2004in the step S3007.

As described above, according to the first embodiment, when the printer108is switched to the power saving mode, the main program to be executed by the CPU2001is stored in the RAM2002, and then the FET11001interrupts the power supply to the CPU2001. When the printer108recovers from the power saving mode to the normal operating mode, the flip-flop circuit (FF)11002operates in response to the signal form the logic OR gate11004to turn off the FET11001to cause the same to supply power to the CPU2001, and the CPU2001supplied with power is started to read out the main program stored in the RAM2002, for execution.

The power consumed by the CPU2001is relatively high, so that during execution of the power saving mode, the power consumption of the controller unit2001is reduced.

Further, when the printer108recovers the normal operating mode from the power saving mode, the CPU2001reads out and executes the main program from the RAM2002supplied with power during execution of the power saving mode and storing the main program. Therefore, compared with the case where the main program is downloaded from the hard disk device2004, it is possible to realize high-speed recovery of the normal operation mode. What is more, it is not necessary to use a sub CPU as in the prior art, either, which makes it possible to realize high-speed recovery from the power saving mode with an inexpensive information processing apparatus.

Although the first embodiment relates to the operation of the controller unit2000installed in the printer108, in the power saving mode thereof, the controller unit capable of operating in the power saving mode according to the present invention is not necessarily required to be installed in an image forming apparatus, such as a printer, but the present invention is applicable to controller units (information processing apparatuses) in general, but by no means limited by the objects to be controlled by such controller units.

Next, a description will be given of a second embodiment of the present invention.

FIG. 27is a block diagram showing the configuration of a network system incorporating an image forming apparatus as an image processing apparatus according to the second embodiment.

InFIG. 27, reference numeral50designates an image forming apparatus, such as a digital multifunction machine, and which is equipped with a main function of outputting images. In the image forming apparatus50, reference numeral140designates an operating section for performing various input operations on the image forming apparatus50,10a scanner unit for reading image information according to instructions from the operating section140, and20a printer unit for printing image information on sheets.

Reference numeral30designates a controller unit that performs control of input and output of image information to and from the scanner unit10and the printer unit20according to instructions from PCs (Personal Computers)212and213. When print data as the image information is supplied from the PC212or213via a LAN211, the controller unit30causes the printer unit20to print out (output the image of) the print data.

FIG. 28is a cross-sectional view showing the internal construction of the image forming apparatus50shown inFIG. 1. Hereafter, a description will be given of the operation of the image forming apparatus50with reference toFIG. 28.

First, in the scanner unit10, reference numeral3101designates an original platen glass plate, onto which originals fed from an automatic sheet feeder3142are sequentially placed in a predetermined position. Reference numeral3102designates an original illuminating lamp implemented e.g. by a halogen lamp, for irradiating an original placed on the original platen glass3101. Reference numerals3103,3104, and3105designate scanning mirrors, which are contained in an optical scanning unit, not shown, together with the original illuminating lamp3102, and which make reciprocating motions to guide reflected light from the original to a CCD unit3106. The CCD unit3106is comprised of an image pickup element3108implemented e.g. by a CCD, a focusing lens3107for focusing the reflected light from the original on the image pickup element3108, a CCD driver3109for driving the image pickup element3108, and so forth. An image signal from the image pickup element3108is delivered to the controller unit30.

Next, in the printer unit20, reference numeral110designates a photosensitive drum, which is destaticized by a pre-exposure lamp112to prepare for image formation. Reference numeral113designates a primary electrostatic charger that uniformly electrifies the photosensitive drum110. Reference numeral117designates an exposure section, which is implemented e.g. by a semiconductor laser, and irradiates the photosensitive drum110based on the image data processed by the controller unit30to form a static latent image thereon, as will be described hereinafter. Reference numeral118designates a developing unit118containing a black developer (toner), while119designates a pre-transfer electrostatic charger that applies high voltage to the photosensitive drum110before a toner image developed on the photosensitive drum110is transferred to a sheet.

Reference numerals120,122,124,142, and144designate sheet feed units (120designates a manual feed unit). Sheet feed rollers121,123,125,143, and145associated with the respective sheet feed units are driven to feed transfer sheets into the printer unit20. A transfer sheet fed from each sheet feed unit is once stopped at a location where a registration roller126is disposed, and then advanced from the registration roller126in synchronism with read-out timing in which the image formed on the photosensitive drum110is read out. Reference numeral127designates a transfer electrostatic charger that transfers a toner image formed on the photosensitive drum110to the transfer sheet fed thereto. Reference numeral128designates a separating electrostatic charger that separates the transfer sheet on which a transfer operation has been completed, from the photosensitive drum110. The toner remaining on the photosensitive drum110without being transferred is collected by a cleaner111. Reference numeral129designates a conveyor belt that conveys the transfer sheet on which the transfer process has been completed to a fixing unit130, where the sheet is fixed e.g. by heat.

Reference numeral131designates a flapper that switches the conveying direction of the transfer sheet, for which the transfer process has been completed, between a direction toward a sorter132and a direction toward an intermediate tray137. Further, reference numerals133to136designate feed rollers, which feed the transfer sheet, for which the fixing process has once been completed, after inverting the same (for multiple printing) or without inverting the same (for double-sided printing). Reference numeral138designates a re-feed roller that again feeds the transfer sheet placed on the intermediate tray137up to a location where the registration roller126is disposed.

The controller unit30includes a microcomputer, referred to hereinafter, an image processing section, and so forth, and performs an image forming process according to instructions from the operating section140.

FIG. 29is a block diagram showing the internal arrangement of the controller unit30.

The controller unit30is connected to the scanner unit10as the image input device, and the printer unit20as the image output device, and further connected to a LAN211and a public line (WAN)251, for controlling the input and output of image information and device information. A CPU (Central Processing Unit)201controls the overall system. A RAM202is a system work memory used for the CPU201to operate, and also serves as an image memory for temporarily storing image data. A ROM203is a boot ROM that stores a boot program of the system. A HDD204is a hard disk drive that stores system software, image data, and software counter values, and so forth.

An operating section I/F270interfaces with the operating section140, and outputs image data to be displayed on the operating section140to the same, and information that the user has inputted to the operating section2012to the CPU201. A network section210is connected to the LAN211to input and output information. A MODEM250is connected to the public line251to input and output information. A scanner and printer communication I/F206provides an interface for communication with respective CPUs included in the scanner unit10and the printer unit20. The devices described above are connected to a system bus207.

An image bus I/F205is a bus bridge that connects between the system bus207and an image bus208that transfers image data at high speed and converts the data structure. The image bus208is implemented by a PCI bus or an IEEE 1394 bus. Connected to the image bus2008are devices described hereinafter.

A raster image process (RIP)260expands a PDL code into a bit map image. A device I/F section220connects the scanner unit10and the printer unit20as the image input and output devices to the controller unit30to carry out synchronous to asynchronous conversion of image data. A scanner image processing section280corrects, processes, and edits inputted image data. A printer image processing section290performs correction, resolution conversion, and so forth, on image data for printing output, so as to adapt the image data to the performance of the printer unit20. An image rotation section230rotates image data. An image compression section240performs JPEG-based compression and expansion of multivalued image data, and JBIC-, MMR-, or MH-based compression and expansion of binary image data.

Power is supplied from a power supply40to the controller unit30via a power ON/OFF section41, wherein feed lines to circuit elements of the controller unit30are divided into a plurality of feeding systems43and44which are selectively turned on and off. The power supply40is a device that converts commercial AC power to DC power. The feed line43is connected to the devices201,203to206,220,230,240,260,280, and290, and the feed line44is connected to the devices202,210,250, and270.

Next, a description will be given of a sequence of operations of the image forming apparatus50, including the start, printing output, transition to the power saving mode, and recovery from the power saving mode, with reference toFIG. 29.

First, a main switch (SW), not shown, of the image forming apparatus50is turned on, power starts to be supplied from the power supply40to the controller unit30, and the power ON/OFF section41causes both the feed lines43and44to be turned on (execute feeding of power). This causes the controller unit30to start a boot sequence according to the boot program stored in the ROM203.

A system program for executing the sequence of boot operations of the image forming apparatus50is stored in the HDD204, and according to the boot sequence, the system program is read from the HDD204to be stored in the RAM202. The CPU201executes the system program downloaded into the RAM202whereby a sequence of operations of the image forming apparatus are executed.

Now, a description will be given of an example of operations executed by the image forming apparatus50, for printing out image information sent from the PC212or PC213connected to the LAN211.

In the controller unit30, the CPU201causes print data as image information sent from the PC212or the PC213connected to the LAN211to be stored via the network section210in the RAM202. The print data is read out from the RAM202, and sent to the RIP260via the image bus I/F205to the RIP260. The print data is in the form of PDL (Page Description Language) data, and in the RIP260, the PDL data is expanded into bit map data, and then the bit map data is compressed by the image compression section240, as required, and accumulated in the HDD204via the image bus I/F205.

In executing printing output to the printer unit20, the bit map data accumulated in the HDD204is sent via the image bus I/F205to the image compression section240, wherein it is expanded this time, and then the printer image processing section290performs correction, resolution conversion, and so forth, on the expanded bit map image data so as to adapt the same to the performance of the printer20. After being rotated, as required, by the image rotation section230, the image data is sent via the device I/F220to the printer unit20, wherein it is printed out.

Next, a description will be given of a transition to the power saving mode of the image forming apparatus50executed by the controller unit30.

In transition to the power saving mode, the CPU201controls the power ON/OFF section41via the line46, such that the power ON/OFF section41turns off the feed line43(stops feeding of power) and keeps the feed line44on (continues to execute feeding of power).

Thus, during execution of the power saving mode, the power ON/OFF section41turns off the feed line43, so that the power consumption by the main circuit elements of the controller unit30, including the CPU201, is reduced. What is more, since the feed line44to the network section210of the controller unit30is kept on, the network section210is capable of giving a power-on instruction to the power ON/OFF section41via the line45, when a signal is received via the LAN211by the network section210, even during execution of the power saving mode. Upon receiving the power-on instruction from the network section210, the power ON/OFF section41turns on the feed line43as well to switch the image forming apparatus50to the normal operation mode. This operation will be described in detail hereinafter.

During execution of the power saving mode, the power is also supplied to the RAM202, due to the self-refresh operation, the system program stored in the RAM202is preserved without being erased.

Further, during execution of the power saving mode, the power is also supplied to the MODEM250, which makes it possible to perform facsimile communications using the public line251, even during execution of the power saving mode.

Also, during execution of the power saving mode, the power is also supplied to the operating section I/F270, which makes it possible for the controller unit30to respond to an instruction for recovery of the image forming apparatus50from the power saving mode to the normal operation mode given by the user to the operating section140during execution of the power saving mode.

Next, a description will be given of recovery of the image forming apparatus50from the power saving mode to the normal operation mode executed by the controller unit30.

When a print command is sent from the PC212to the network section210via the LAN211, the network section210receives and interprets the print command to send a control signal to the power ON/OFF section41via the line45. Responsive to the control signal, the power ON/OFF section41turns on the feed line43.

When the feed line43is turned on, the CPU201is activated, and at this time, the CPU201determines, from the operative status of the power ON/OFF section41, whether the activation of the CPU201is caused by recovery from the power saving mode to the normal operation mode, or turn-on of the main switch of the image forming apparatus50. If the determination result shows that the activation is caused by the recovery from the power saving mode, the CPU201executes the system program which was stored in the RAM upon transition to the power saving mode with execution of the operation of downloading the system program from the HDD204into the RAM202being omitted among the above described boot sequence of operations.

This enables the CPU201to respond to the print command received from the PC212to thereby cause the printer unit20to perform printing output.

After the printing output is completed, the CPU201starts measurement of time, and if no external input has occurred for a predetermined time period, the CPU201gives an instruction for switching the controller unit30to the power saving mode to the power ON/OFF section41. In response to the instruction, the power ON/OFF section41turns off the power line43. This switches the controller unit30to the power saving mode in which the power consumption is reduced.

As described above, according to the second embodiment as well, during execution of the power saving mode, the power consumption by the controller unit30can be largely reduced, and what is more, it is possible to realize high-speed recovery of the normal operation mode.

Although also the above-described second embodiment relates to the operation of the controller unit30installed in the image forming apparatus50in the power saving mode thereof, the controller unit capable of operating in the power saving mode according to the present invention is not necessarily required to be installed in an image forming apparatus, but the present invention is applicable to controller units (information processing apparatuses) in general, but by no means limited by the object to be controlled by such controller units.

Next, a description will be given of a third embodiment of the present invention with reference toFIGS. 31 to 33.

FIGS. 31 to 33in the third embodiment correspond toFIGS. 24 to 26in the first embodiment described above, but are distinct from the latter in that a logic OR gate11009is provided.

The third embodiment realizes a controller unit2000which properly operates in whatever timing a recovery causing signal (a signal (power on (UI))) indicative of user's input to the operating section2012, a signal (power on (network)) indicative of reception of print data by the network section2010, or a signal (power on (FAX)) indicative of reception of facsimile data by the MODEM2050) are inputted to the logic OR gate11004.

In the case of the control unit2000in the first embodiment inFIG. 24, when the CPU2001determines that the normal operating mode should be switched to the power saving mode, the output from the general output port GP0<0> thereof to the PR terminal of the flip-flop circuit11002is changed to thereby preset the output from the Q terminal of the flip-flop circuit11002to a high level.

In this case, even if the recovery causing signal is inputted to the logic QR gate11004before the CPU2001changes the output from the general output port GP0<0> thereof to the PR terminal of the flip-flop circuit11002, the output from the Q terminal of the flip-flop circuit11002is preset to a high level. Therefore, even when the printer108should be set to the normal operation mode, the switching of the FET11001turns off the second power supply system.

Then, since the second power supply system is turned off, the power supply to the CPU2001is interrupted. More specifically, in this case, the printer108turns off the second power supply system, so that the printer108enters the power saving mode. As will be understood from the above, the controller unit2000in the first embodiment is disadvantageous in that the second power supply system is once turned off even when the recovery causing signal for recovery of the normal operation mode is inputted, and therefore, to recover the printer108into the operative state, the recovery process of the CPU2001needs to be executed by turning on the second power supply system, which takes time.

The third embodiment solves the above-described problem in the following manner.

First, as shown inFIG. 31, when the recovery causing signal is inputted to the controller unit2000, the signal is inputted to the logic OR gate11009, which in turn generates and applies a signal for clearing the output from the Q terminal to the CLR terminal of the flip-flop circuit11002.

Then, when the CPU2001determines that the normal operation mode should be switched from the normal operating mode to the power saving mode, the output from the general output port GP0<0> to the PR terminal of the flip-flop circuit11002is changed. Since the signal for clearing the output from the Q terminal has been inputted from the logic OR gate11009to the CLR terminal of the flip-flop circuit11002, even if the output to the PR terminal is changed (even if the CPU2001generates the power saving mode transition signal), the output from the Q terminal is not preset to the high-level. Namely, the FET11001does not turn off the second power supply system, so that the power supply to the CPU2001is not shut down. That is, in this case, the printer108does not turn off the second power supply system, so that the printer108does not enter the power saving mode.

As described above, the controller unit2000in the third embodiment does not turn off the second power supply system when a recovery causing signal for recovery of the normal operation mode is inputted. As a result, the recovery process of the CPU2001need not be executed which would be necessitated if the second power supply system were once turned off, thus leading to time saving.

FIGS. 32 and 33are similar toFIGS. 25 and 26in the first embodiment, and are distinct from the latter only in that the logic OR gate11009is provided. The operations of the controller unit2000inFIGS. 32 and 33are similar to those of the controller unit2000inFIGS. 25 and 26, and therefore duplicate description thereof is omitted.

As described above, according to the third embodiment, even when a transition signal for causing the image processing apparatus to switch from a first power supply status a second power supply status in which power consumption is reduced is received immediately after receiving a recovery signal indicative of a factor for causing the image processing apparatus to switch from the second power supply status to the first power supply state, it is possible to maintain the first power supply state without entering the second power supply status.