JP2009251226A - Image forming apparatus, image forming program, and computer-readable recording medium recording this program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of reducing electric power consumption following running-out of paper. <P>SOLUTION: The operation mode of this image forming is set to an electric power saving mode (S108) for reducing electric power consumption by shutting off supply of electric power to a fixing heater and a light source lamp, when the number of paper sheets remaining in a paper feeding cassette detected by a remaining paper detection part is below a predetermined value (YES at S102). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power saving control technique for an image forming apparatus.

  As is well known, a digital image forming apparatus is a multifunction machine having a wide range of functions such as a copying machine, a facsimile, a printer, and a scanner.

  Specifically, when used as a copying machine, an image reading unit and an image forming unit are used. When used as a facsimile, only the image reading unit is used during transmission, and only the image forming unit is used during reception. When used as a printer, only the image forming unit is used. When used as a scanner, only the image reading unit is used.

  By the way, energy saving due to environmental problems in recent years has been pointed out, and the above-mentioned digital image forming apparatus is also required to save energy.

  The digital image forming apparatus having the above configuration is selected and used as an image reading unit and an image forming unit depending on the usage situation such as a copying machine, a facsimile, a printer, and a scanner. Even in a high digital image forming apparatus, the image reading unit is maintained in an operable state, thereby consuming extra power. Further, even in a digital image forming apparatus that is frequently used as a scanner, the image forming unit is maintained in an operable state, so that extra power is consumed.

In order to cope with such a situation, in Patent Document 1, the frequency of use of at least one of the image reading unit and the image forming unit for a certain period is measured, and the image reading unit, the image forming unit, and the like are measured at the measured usage frequency. A technology has been proposed in which the time for shifting from at least one of the normal mode to the power saving mode is changed to save power.
JP 2003-307980 A

  By the way, in the image forming apparatus, there is a case where printing is started when the remaining amount of paper is insufficient, and printing is interrupted due to running out of paper. In such a case, it is necessary to replenish the paper, and as a result, the completion of the job is delayed after the paper is replenished. Therefore, the standby power consumed until the start of printing, which was consumed in order to start printing immediately, is wasted.

  Although the technique described in Patent Document 1 saves power by changing the time until the transition from the normal mode to the power saving mode, the waste of standby power due to the print interruption due to the out of paper is reduced. The fact is that no consideration is given to.

  The present invention has been made in view of the above circumstances, and provides an image forming apparatus, an image forming program, and a computer-readable recording medium on which the program is recorded, which can reduce power consumed when the paper runs out. Objective.

  An image forming apparatus viewed from a first aspect of the present invention includes a paper storage unit for storing paper, and a remaining amount detection unit for detecting the remaining amount of paper stored in the paper storage unit. If the remaining amount of paper in the paper storage unit detected by the remaining amount detection unit is equal to or less than a predetermined value, the operation mode of the device can be reduced by cutting off the power supply to a specific circuit. Control means for setting the power saving mode to be reduced is included.

  In recent image forming apparatuses, the number of sheets fed from the sheet storage unit that stores A4 size paper accounts for 90% or more of the total number of sheets fed in all the sheet storage units. Assuming that only the paper storage unit that stores A4 size paper is used, the A4 size paper is more important than the convenience of using the paper storage unit of other size paper without waiting time. It is preferable to set the power saving mode when the remaining amount of paper in the paper storage unit is equal to or less than a predetermined value.

  Therefore, in one aspect, a plurality of paper storage units are provided, and the control unit detects that the remaining amount of paper in a specific paper storage unit among the plurality of paper storage units is equal to or less than a predetermined value by the remaining amount detection unit. Means for setting the device to a power saving mode when is detected.

  Here, in the specific paper storage unit, the ratio of the number of paper storage sheets is a predetermined ratio between the number of paper sheets fed from the specific paper storage unit and the total number of paper sheets fed from the other paper storage units. This is a sheet storage unit that is equal to or greater than the ratio.

  In another aspect, the sheet storage unit is single.

  In this case, it is possible to shift to the power saving mode without considering the remaining amount of paper in the other paper storage units.

  In another aspect, a plurality of paper storage units are provided, and the control means detects when the remaining amount detection unit detects that the remaining amount of paper in all the paper storage units has become a predetermined value or less. Means for setting the device to a power saving mode.

  In this case, since the power saving mode is set when the remaining amount of paper in all the paper storage units is equal to or less than a predetermined value, power saving can be realized without greatly impairing convenience.

  The image forming apparatus has means for setting the predetermined number of remaining sheets as a minimum number of printed sheets whose frequency is equal to or greater than a predetermined value based on a histogram of the number of printed sheets by the number of printed sheets in one printing. In addition.

  According to the above configuration, it is assumed that the frequency of printing below the minimum number of printed sheets is very low, and if the remaining amount is the minimum number of printed sheets, it is predicted that an interruption in the middle of printing will occur. Power saving is achieved by shifting to.

  In the image forming apparatus, the specific circuit includes a heater of the fixing device.

  Further, in the image forming apparatus, the specific circuit further includes a light source lamp of the document reading unit.

  An image forming program viewed from the second aspect of the present invention includes a paper storage unit for storing paper, and a remaining amount detection unit for detecting the remaining amount of paper stored in the paper storage unit. When the remaining amount of paper in the paper storage unit detected by the remaining amount detection unit is equal to or less than a predetermined value, the operation mode of the device is cut off from the power supply to a specific circuit. It functions as a control means for setting a power saving mode for reducing power consumption.

  A computer-readable recording medium viewed from the third aspect of the present invention includes a paper storage unit for storing paper, and a remaining amount detection unit for detecting the remaining amount of paper stored in the paper storage unit When the remaining amount of paper in the paper storage unit detected by the remaining amount detection unit is equal to or less than a predetermined value, the operation mode of the device is cut off and power supply to a specific circuit is cut off. Thus, an image forming program that functions as a control unit for setting a power saving mode for reducing power consumption is recorded.

As the recording medium, for example, a CPU (Centralal Memory) such as a RAM (Random Access Memory) and a ROM (Read Only Memory).
The memory itself for performing processing in (Processing Unit) may be a recording medium. Further, a program reading device may be provided as an external storage device of a computer, and a recording medium that can be read by being inserted into this device may be used. In any case, the recorded image forming program is executed when the CPU accesses the recording medium. Alternatively, the CPU may read the image forming program from the recording medium, download the read image forming program to the program storage area, and execute it. In this case, the download program is stored in a predetermined storage device in advance. The CPU comprehensively controls each part of the computer so as to perform a predetermined paper feed process according to the installed paper feed program.

  Further, recording media readable by the program reader include (1) magnetic tape, (2) tape system such as cassette tape, flexible disk (FD), magnetic disk such as hard disk, or CD-ROM (Compact Disc-). Disk systems such as optical disks such as Read Only Memory (MO), MO (Magneto Optical Disk), MD (Mini Disk), DVD (Digital Versatile Disk), etc. (3) IC (Integrated Circuit) card including memory card, optical card, etc. And (4) mask ROM, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Era) Examples thereof include a medium that records a program in a fixed manner, including a semiconductor memory such as a flash memory (Sable Programmable Read Only Memory).

  Furthermore, the computer may be configured to be connectable to a communication network including the Internet, and may be a medium that fluidly carries the program so as to download an image forming program from the communication network. When the image forming program is downloaded from the communication network as described above, the download program may be stored in the computer in advance. Moreover, you may install from another recording medium.

  According to the present invention, when the remaining amount of paper in the paper storage unit detected by the remaining amount detection unit is equal to or less than a predetermined value, the operation mode of the apparatus reduces power consumption by cutting off power supply to a specific circuit. Set to power mode. As described above, when the remaining amount of paper is low, by controlling so as to shift to the power saving mode in a short time, wasted standby power is reduced in advance. As a result, useless power can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Overall configuration>
FIG. 1 is a diagram showing a simplified overall configuration of an image forming apparatus 10 according to an embodiment of the present invention.

  Referring to FIG. 1, image forming apparatus 10 according to the present exemplary embodiment performs predetermined processing according to image data transmitted from external client personal computer (hereinafter referred to as “client PC”) 126 shown in FIG. 2. This is a digital multi-function peripheral that forms multicolor and single color images on a single sheet (recording paper), and is composed of an apparatus main body 12 and an automatic document processing apparatus 14.

  The apparatus main body 12 includes an exposure unit 16, a developing device 18, a photosensitive drum 20, a cleaner unit 22, a charger 24, an intermediate transfer belt unit 26, a fixing unit 28, a paper feed cassette 30, a paper discharge tray 32, and the like. ing.

  A document placing table 34 made of transparent glass on which a document is placed is provided on the upper part of the apparatus main body 12, and an automatic document processing device 14 is attached to the upper side of the document placing table 34.

  The automatic document processor 14 automatically conveys the document onto the document table 34. The automatic document processing device 14 is configured to be rotatable in the direction of arrow M, and the document can be placed by hand by opening the document table 34.

  The image data handled in the image forming apparatus 10 corresponds to a color image using each color of black (K), cyan (C), magenta (M), and yellow (Y). Accordingly, four each of the developing device 18, the photosensitive drum 20, the charger 24, and the cleaner unit 22 are provided so as to form four types of latent images corresponding to the respective colors, thereby black, cyan, magenta. And four image stations set to yellow.

  The charger 24 is for uniformly charging the surface of the photosensitive drum 20 to a predetermined potential. In the present embodiment, a charger type is adopted. As the charger 24, a contact roller type and a brush type may be used.

  The exposure unit 16 corresponds to an image writing device, and is configured as a laser scanning unit (LSU) including a laser emitting unit and a reflection mirror. In the exposure unit 16, a polygon mirror that scans the laser beam and optical elements such as a lens and a mirror for guiding the laser beam reflected by the polygon mirror to the photosensitive drum 20 are disposed. As the exposure unit 16, for example, a technique using an EL (Electro Luminescence) and LED (Light Emitting Diode) writing head in which light emitting elements are arranged in an array can also be adopted.

  Since the exposure unit 16 has the above-described configuration, an electrostatic latent image corresponding to the image data is formed on the surface by exposing the charged photosensitive drum 20 according to the input image data. It has the function to do.

  The developing device 18 visualizes the electrostatic latent images formed on the respective photosensitive drums 20 with toner of four colors (YMCK).

  The cleaner unit 22 removes and collects toner remaining on the surface of the photosensitive drum 20 after development and image transfer.

  An intermediate transfer belt unit 26 is disposed above the photosensitive drum 20. The intermediate transfer belt unit 26 includes an intermediate transfer belt 36, an intermediate transfer belt drive roller 38, an intermediate transfer belt driven roller 40, an intermediate transfer roller 42, and an intermediate transfer belt cleaning unit 44.

  Four intermediate transfer rollers 42 are provided corresponding to each color for YMCK. Each of these intermediate transfer rollers 42 provides a transfer bias for transferring the toner image on the photosensitive drum 20 onto the intermediate transfer belt 36.

  The intermediate transfer belt driving roller 38, the intermediate transfer belt driven roller 40, and the intermediate transfer roller 42 are driven to rotate by stretching the intermediate transfer belt 36.

  The intermediate transfer belt 36 is provided in contact with each photosensitive drum 20. The toner images of the respective colors formed on the photosensitive drum 20 are sequentially superimposed and transferred onto the intermediate transfer belt 36, thereby forming a color toner image (multicolor toner image) on the intermediate transfer belt 36. Have. The intermediate transfer belt 36 is formed in an endless shape using, for example, a film having a thickness of about 100 μm to 150 μm.

  The toner image is transferred from the photosensitive drum 20 to the intermediate transfer belt 36 by an intermediate transfer roller 42 that is in contact with the back side of the intermediate transfer belt 36.

  A high voltage transfer bias (a high voltage with a polarity (+) opposite to the toner charging polarity (−)) is applied to the intermediate transfer roller 42 in order to transfer the toner image. The intermediate transfer roller 42 is based on a metal (for example, stainless steel) shaft having a diameter of 8 to 10 mm, and the surface thereof is covered with a conductive elastic material (for example, EPDM and urethane foam). It is. By this conductive elastic material, a high voltage can be uniformly applied to the intermediate transfer belt 36. In this embodiment, a roller shape is used as the transfer electrode, but a brush or the like can also be used.

  As described above, the electrostatic images visualized on the respective photosensitive drums 20 according to the respective hues are stacked on the intermediate transfer belt 36. Thus, the laminated image information is transferred onto the sheet by the transfer roller 46 disposed at the contact position between the sheet and the intermediate transfer belt 36 by the rotation of the intermediate transfer belt 36. At this time, both the intermediate transfer belt 36 and the transfer roller 46 are pressed against each other with a predetermined nip pressure, and a voltage for transferring the toner onto the paper is applied to the transfer roller 46 (the toner charging polarity ( -) Is a reverse voltage (+) high voltage). Further, in order to obtain the nip pressure constantly, the transfer roller 46 uses either one of the transfer roller 46 or the intermediate transfer belt drive roller 38 as a hard material (metal or the like) and the other as a soft material such as an elastic roller. (Elastic rubber roller or foamable resin roller) is used.

  Further, as described above, the toner adhered to the intermediate transfer belt 36 due to contact with the photosensitive drum 20 or the toner remaining on the intermediate transfer belt 36 without being transferred onto the sheet by the transfer roller 46 is used in the next step. Therefore, the intermediate transfer belt cleaning unit 44 is set so as to remove and collect the toner.

  The intermediate transfer belt cleaning unit 44 includes a cleaning blade as a cleaning member that comes into contact with the intermediate transfer belt 36. The intermediate transfer belt 36 that comes into contact with the cleaning blade is driven by an intermediate transfer belt driven roller 40 from the back side. It is supported.

  The paper feed cassette 30 is a tray for storing sheets (recording paper) used for image formation, and is provided below the exposure unit 16 of the apparatus main body 12. In the image forming apparatus 10, a sheet used for image formation can also be placed in the manual paper feed cassette 48.

  A paper discharge tray 32 provided above the apparatus main body 12 is a tray for collecting printed sheets face down.

  The apparatus main body 12 is provided with a substantially vertical sheet conveyance path S for feeding the sheets of the sheet feeding cassette 30 and the manual sheet feeding cassette 48 to the sheet discharge tray 32 via the transfer roller 46 and the fixing unit 28. Yes. In the vicinity of the paper transport path S from the paper feed cassette 30 or the manual paper feed cassette 48 to the paper discharge tray 32, pickup rollers 50a and 50b, a plurality of transport rollers 52a, 52b, 52c and 52d, a registration roller 54, and a transfer roller 46, a fixing unit 28, and the like.

  The conveyance rollers 52 a to 52 d are small rollers for promoting and assisting the conveyance of the sheet, and a plurality of the conveyance rollers 52 a to 52 d are provided along the sheet conveyance path S.

  The pickup roller 50 a is provided near the end of the paper feed cassette 30, picks up sheets one by one from the paper feed cassette 30, and supplies them to the paper transport path S. Similarly, the pickup roller 50 b is provided in the vicinity of the end of the manual paper feed cassette 48, picks up sheets one by one from the manual paper feed cassette 48, and supplies them to the paper transport path S.

  The registration roller 54 temporarily holds the sheet conveyed through the sheet conveyance path S, and conveys the sheet to the transfer roller 46 at the timing when the leading edge of the toner image on the photosensitive drum 20 is aligned with the leading edge of the sheet. It has a function to do.

  The fixing unit 28 includes a heat roller 56 and a pressure roller 58, and the heat roller 56 and the pressure roller 58 rotate with the sheet interposed therebetween.

  The heat roller 56 incorporates a fixing heater 128 (see FIG. 2). The heat roller 56 is energized and controlled so that the fixing heater 128 therein has a predetermined fixing temperature based on a signal from the fixing temperature sensor 130 (see FIG. 2), and heats the toner together with the pressure roller 58 to the sheet. The multi-color toner image transferred onto the sheet by pressure bonding is melted, mixed, and pressed to have a function of thermally fixing the sheet.

  The fixing unit 28 is provided with an external heating belt 60 for heating the heat roller 56 from the outside.

  Here, the sheet conveyance path will be described in detail.

  As described above, the image forming apparatus 10 is provided with the paper feed cassette 30 and the manual paper feed cassette 48 that store sheets in advance. In order to feed sheets from these sheet feeding cassettes 30 and 48, pickup rollers 50a and 50b are arranged, respectively, to guide the sheets one by one to the transport path S.

  The sheet conveyed from each of the sheet feeding cassettes 30 and 48 is conveyed to the registration roller 54 by the conveying roller 52a in the sheet conveying path S, and at the timing when the leading edge of the sheet and the leading edge of the image information on the intermediate transfer belt 36 are aligned. It is conveyed to the transfer roller 46 and image information is written on the sheet. Thereafter, the sheet passes through the fixing unit 28, whereby unfixed toner on the sheet is melted and fixed by heat, and then discharged onto the paper discharge tray 32 through the conveyance roller 52 b.

  The above-mentioned conveyance path is for a single-sided printing request for a sheet. On the other hand, in the case of a double-sided printing request, the trailing edge of the sheet that has finished single-sided printing and has passed through the fixing unit 28 as described above. When the sheet is nipped by the final conveyance roller 52b, the conveyance roller 52b rotates reversely to guide the sheet to the conveyance rollers 52c and 52d. Thereafter, after printing is performed on the back surface of the sheet through the registration roller 54, the sheet is discharged to the discharge tray 32.

<Electrical configuration>
FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus 10.

  Referring to FIG. 2, the image forming apparatus 10 includes a main CPU 100 that controls the entire control center of the image forming apparatus 10. The BUS 102 extending from the main CPU 100 includes an ROM 104, a RAM 106, an image memory 108, an image processing unit 109, an HDD (Hard Disk Drive) 110, an NIC (Network Interface Card) 112, an operation panel 114, and an image forming unit 28 including a fixing unit 28. A sub CPU (hereinafter referred to as “first sub CPU”) 118 that controls 116, and a sub CPU (hereinafter referred to as “second sub CPU”) that controls document reading unit 120 including exposure unit 16. 122 and a timer IC (Integrated Circuit) 124 are connected.

  The main CPU 100 controls each input / output device according to a program written in the ROM 104 in advance, and temporarily stores data input / output during this time in a predetermined memory area of the RAM 106.

  The image memory 108 stores the image data output from the image processing unit 109.

  The print data and password transmitted from the client PC 126 are stored in the HDD 110.

  The operation panel 114 includes an input key and a liquid crystal display panel. The operation panel 114 displays the status of the apparatus, usable paper size, copy magnification, and the like, and can accept an operator's operation using the input key. The liquid crystal display panel may be a liquid crystal touch panel that allows input by touching the liquid crystal screen.

  The NIC 112 is a communication unit for communicating with the client PC 126 via a communication line (not shown). The image forming apparatus 10 performs printing based on print data transferred from the client PC 126, or transfers image data obtained by reading a document via the NIC 112 to the client PC 126.

  The image forming unit 116 is controlled by the first sub CPU 118 as described above. The image forming unit 116 includes a first driver 132, an A / D (Analog-Digital) converter 134, and a first remaining amount in addition to the fixing heater 128 and the fixing temperature sensor 130 provided in the fixing unit 28. A detection unit 136 and a second remaining amount detection unit 138 are included.

  The fixing temperature sensor 130 detects the temperature of the heat roller 56 in the fixing unit 28 and outputs the temperature data to the first sub CPU 118. The main CPU 100 transmits a predetermined warm-up command to the first sub CPU 118 as the first return process. When the first sub CPU 118 receives a predetermined warm-up command from the main CPU 100, the first sub CPU 118 energizes the fixing heater 128, and the heat roller 56 heated by the fixing heater 128 based on the temperature information obtained from the fixing temperature sensor 130. The energization of the fixing heater 128 is controlled so that the surface temperature is fixed at a predetermined temperature. If the surface of the heat roller 56 reaches a predetermined temperature, the first sub CPU 118 determines that the processable state (ready state) has been reached, and notifies the main CPU 100 accordingly.

  The first remaining amount detection unit 136 is disposed in the paper feed cassette 30. On the other hand, the second remaining amount detection unit 138 is disposed in the manual paper feed cassette 48. Each of the remaining amount detection units 136 and 138 is provided with a lever that is provided so that the leading end abuts on the uppermost surface of the paper loaded in each of the paper feeding cassettes 30 and 48 and the other end is rotatably supported by a support shaft. The remaining amount of paper is detected by the angle of this lever.

  The document reading unit 120 is controlled by the second sub CPU 122. The document reading unit 120 includes a light source lamp 140 and a light amount sensor 142, a second driver 146, and an A / D converter 148 provided in the exposure unit 16.

  The light amount sensor 142 detects the amount of light emitted from the light source lamp 140 of the exposure unit 16 and inputs light amount data to the second sub CPU 122. The main CPU 100 transmits a predetermined warm-up command to the second sub CPU 122 as the second return process. When receiving a predetermined warm-up command from the main CPU 100, the second sub CPU 122 energizes the light source lamp 140, and based on the light amount information obtained from the light amount sensor 142, the light amount of the light source lamp 140 is fixed to the predetermined light amount. Thus, the energization of the light source lamp 140 is controlled. When the light amount of the light source lamp 140 reaches a predetermined light amount, the first sub CPU 118 determines that the processable state (ready state) has been reached, and notifies the main CPU 100 accordingly.

The first driver 132 drives the fixing heater 128 built in the heat roller 56 of the fixing unit 28 based on the control data output from the first sub CPU 118. On the other hand, the second driver 146 drives the light source lamp 140 of the exposure unit 16 based on the control data output from the second sub CPU 122.
In addition to the above, the first sub CPU 118 and the second sub CPU 122 have many operations that operate during the document reading process and the image forming process such as the motor, clutch, solenoid, and sensor in the image forming unit 116 and the document reading unit 120. I / O devices are connected. The first sub CPU 118 and the second sub CPU 122 read sensor detection data at a predetermined timing during document reading processing and image formation processing, and drive a motor or the like according to the detection data.

  The timer IC 124 is an IC for measuring time, and outputs the time after being reset.

<Software configuration>
In this embodiment, when the remaining amount of paper in the paper feed cassette 30 or 48 becomes a predetermined value or less, the operation mode of the apparatus is set to the fixing heater 128 of the fixing unit 28 and the light source lamp 140 of the exposure unit 16. It is programmed to be set to a power saving mode that reduces power consumption by cutting off the power supply.

  Such a program is stored in the ROM 104, and realizes various functions of the image forming apparatus 10 described below. The realization of these functions is achieved by the main CPU 100 and the sub CPUs 118 and 122 executing the above programs.

  FIG. 3 is a diagram showing the structure of the image forming program of the image forming apparatus 10 in the form of a flowchart.

  Referring to FIG. 3, the image forming program includes a process for determining whether or not the remaining amount of paper in the paper feed cassette 30 or 48 is equal to or less than a predetermined value, and the remaining amount of paper in the paper feed cassette 30 or 48 is predetermined. If the value is equal to or smaller than the value, the process of setting the time-up value T (variable) to “T1”. If it is set to “T0 (> T1)”, whether the output value of the timer IC 124 exceeds the value of the variable T (that is, time-up), and time-up, the power saving mode Including processing to change to

<Operation>
The operation of the image forming apparatus 10 will be described with reference to the flowchart shown in FIG.

  First, the main CPU 100 resets the count value of the timer IC 124 (step S100).

  Thereafter, based on detection signals from the first remaining amount detecting unit 136 and the second remaining amount detecting unit 138, the first sub CPU 118 determines whether or not the remaining amount of paper in the sheet feeding cassette 30 or 48 is equal to or less than a predetermined value. Is determined (step S102). Control branches according to the determination result.

  If the remaining amount of paper in the paper feed cassette 30 or 48 is less than or equal to the predetermined value, the first sub CPU 118 notifies the main CPU 100 to that effect, and in response to this, the main CPU 100 sets the time-up value T to “ T1 (10 seconds in this embodiment) "is set (step S104). Thereafter, the control proceeds to step S106. On the other hand, if the remaining amount of paper in the paper feed cassette 30 or 48 is equal to or greater than a predetermined value, the time-up value T is set to “T0 (3 minutes in the present embodiment)” (step S108). Thereafter, the control proceeds to step S106.

  When the control proceeds to step S106, the main CPU 100 determines whether or not the output value of the timer IC 124 exceeds the value of the variable T and the time is up. Control branches according to the determination result.

  If the time is up, the main CPU 100 changes to the power saving mode (step S108). Specifically, the main CPU 100 outputs a power saving mode setting command to the first sub CPU 118 and the second sub CPU 122, and in response to this, the first sub CPU 118 supplies power to the fixing heater 128. The second sub CPU 122 stops supplying power to the light source lamp 140. Thereafter, the control proceeds to step S110. On the other hand, if the time is not up, the main CPU 100 advances the control to step S110 without performing any control.

  When the control proceeds to step S110, the main CPU 100 waits for a print request (pressing a copy button, sending print data, etc.) from the user. When there is a print request, the main CPU 100 determines whether or not the operation mode is the power saving mode (step S112). Control branches according to the determination result.

  If the power saving mode is set, the main CPU 100 cancels the power saving mode (step S114). Specifically, the main CPU 100 outputs a power saving mode cancel command to the first sub CPU 118 and the second sub CPU 122, and in response to this, the first sub CPU 118 supplies power to the fixing heater 128. The second sub CPU 122 resumes power supply to the light source lamp 140. Thereafter, the control proceeds to step S116. On the other hand, if the power saving mode is not set, the main CPU 100 advances the control to step S116 without performing any control.

  When the control proceeds to step S116, a printing process is performed. When this printing process is completed, control returns to step S100.

<Action and effect>
As is apparent from the above description, according to the present embodiment, the following operations and effects are achieved.

  When the remaining amount of paper in the paper cassettes 30 and 48 detected by the remaining amount detection units 136 and 138 is less than a predetermined value, the operation mode of the apparatus is consumed by cutting off the power supply to the fixing heater 128 and the light source lamp 140. The power saving mode is set to reduce power. As described above, when the remaining amount of paper is low, by controlling so as to shift to the power saving mode in a short time, wasted standby power is reduced in advance. As a result, useless power can be reduced.

  The present invention is not limited to the above embodiment.

  For example, the paper feed cassette whose remaining amount is detected by the remaining amount detection unit may be limited to a specific paper feed cassette. In this case, the specific sheet cassette has a predetermined number of sheets, and the ratio between the number of sheets fed from the specific sheet cassette and the total number of sheets fed from other sheet cassettes is predetermined. The paper feed cassette is greater than the ratio. Specifically, if the number of sheets fed from A4 size paper feed cassettes occupies 90% or more of the total number of paper feeds of all cassettes, the remaining amount of paper in the A4 size paper feed cassette is less than a predetermined value. At the time of, set to the power saving mode. In this modification, it is assumed that the image forming apparatus substantially uses only A4 size paper cassettes, and power saving performance is more important than the convenience of using other paper cassettes without waiting time. It is assumed that this is done.

  Further, a single paper cassette may be provided. In this case, it is possible to shift to the power saving mode without having to consider the remaining amount of other sheet cassettes.

  Further, when there is no great difference in the usage frequency of each paper feed cassette, the power saving mode may be set when the remaining amount of paper in all the paper feed cassettes is equal to or less than a predetermined value. In this case, power saving can be realized without greatly reducing convenience.

  Furthermore, the predetermined value of the remaining amount of paper may be set to the minimum number of printed sheets whose frequency of printing is equal to or greater than the predetermined value X based on the histogram of the number of printed sheets by the number of printed sheets in one printing. For example, a histogram is created with the horizontal axis representing the number of printed sheets of 10 or less, 10-20 sheets, 20-30 sheets, and 30 sheets or more in one printing, and the printing frequency being the vertical axis. Then, for example, a histogram as shown in Table 1 below can be obtained.

上記の場合、所定値Ｘを「１０」とすると印字回数の頻度が所定値以上である最小印刷枚数は１１枚となる（第２欄の塗りつぶした階層が該当する）。したがって、残量の所定値として、１０枚が設定される。すなわち、１０枚以下の印刷頻度が非常に少ないとみなして、残量１０枚であれば印刷途中での中断が発生すると予測し、その場合に省電力モードに速やかに移行することで省電力を達成する。

In the above case, when the predetermined value X is “10”, the minimum number of printed sheets whose frequency of printing is equal to or greater than the predetermined value is 11 (the painted layer in the second column corresponds). Therefore, 10 sheets are set as the predetermined value of the remaining amount. In other words, assuming that the frequency of printing 10 sheets or less is very low, if the remaining amount is 10 sheets, it is predicted that an interruption in the middle of printing will occur, and in this case, the power saving mode can be achieved by promptly shifting to the power saving mode. Achieve.

  As another example, if the histogram is created as shown in Table 2 below, the minimum number of printed sheets whose frequency of printing is equal to or greater than a predetermined value is one. Accordingly, 0 is set as the predetermined value of the remaining amount.

その他、本明細書に添付の特許請求の範囲内での種々の設計変更及び修正を加え得ることは勿論である。

It goes without saying that various design changes and modifications can be made within the scope of the claims attached to this specification.

  That is, the embodiment disclosed in this specification is merely an example, and the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by the claims of the appended claims in consideration of the description of the present specification, and includes all modifications within the meaning and scope equivalent to the words described therein. .

1 is a diagram schematically illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus. FIG. 3 is a diagram illustrating a structure of an image forming program of the image forming apparatus in a flowchart format.

Explanation of symbols

10 Image forming apparatus 30, 48 Paper feed cassette 100 Main CPU
104 ROM
106 RAM
118,122 Sub CPU
128 Fixing heater 140 Light source lamp

Claims (10)

A paper storage section for storing paper,
An image forming apparatus comprising: a remaining amount detecting unit for detecting a remaining amount of paper stored in the paper storing unit;
When the remaining amount of paper in the paper storage unit detected by the remaining amount detection unit is equal to or less than a predetermined value, the operation mode of the apparatus is changed to a power saving mode in which power consumption is reduced by cutting off power supply to a specific circuit. An image forming apparatus including a control unit for setting. A plurality of the paper storage portions are provided,
The control unit sets the apparatus to the power saving mode when the remaining amount detection unit detects that the remaining amount of paper in a specific sheet storage unit of the plurality of sheet storage units is equal to or less than a predetermined value. The image forming apparatus according to claim 1, comprising means for setting.   In the specific paper storage unit, the ratio of the number of paper sheets to be fed from the specific paper storage unit to the total number of paper sheets fed from the other paper storage units is equal to or greater than a predetermined ratio. The image forming apparatus according to claim 2, wherein the image forming apparatus is a paper storage unit.   The image forming apparatus according to claim 1, wherein the sheet storage unit is single. A plurality of the paper storage portions are provided,
The control means includes means for setting the apparatus to the power saving mode when the remaining amount detecting unit detects that the remaining amount of sheets in all the sheet storage units is equal to or less than a predetermined value. The image forming apparatus according to claim 1.   5. The apparatus according to claim 1, further comprising means for setting, as the predetermined value of the remaining amount of paper, a minimum number of printed sheets whose frequency of printing is greater than or equal to a predetermined value based on a histogram of the number of printed sheets in one printing. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, wherein the specific circuit includes a heater of a fixing device.   The image forming apparatus according to claim 7, wherein the specific circuit further includes a light source lamp of a document reading unit. A paper storage section for storing paper,
The computer is applied to an image forming apparatus provided with a remaining amount detecting unit for detecting the remaining amount of sheets stored in the sheet storing unit,
When the remaining amount of paper in the paper storage unit detected by the remaining amount detection unit is equal to or less than a predetermined value, the operation mode of the apparatus is changed to a power saving mode in which power consumption is reduced by cutting off power supply to a specific circuit. An image forming program that functions as a control unit for setting. A paper storage section for storing paper,
The computer is applied to an image forming apparatus provided with a remaining amount detecting unit for detecting the remaining amount of sheets stored in the sheet storing unit,
When the remaining amount of paper in the paper storage unit detected by the remaining amount detection unit is equal to or less than a predetermined value, the operation mode of the apparatus is changed to a power saving mode in which power consumption is reduced by cutting off power supply to a specific circuit. A computer-readable recording medium on which an image forming program is recorded, which functions as a control unit for setting.

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