JP2005091905A - Image forming apparatus, processing cartridge, and double-sided print control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for previously preventing the occurrence of useless toner. <P>SOLUTION: The image forming apparatus transfers a first clear image formed on a first image carrier 1 by an image forming means from the first image carrier 1 to a second image carrier 10, furthermore, transfers to a third image carrier 100, transfers the transferred first clear image on one face of a recording medium P, transfers a second clear image formed on the first image carrier 1 by the image forming means from the first image carrier 1 to the second image carrier 10, transfers the transferred second clear image on the other face of the recording medium P and transfers a clear image on both the faces of the recording medium P. The image forming apparatus detects a residual amount of a developer supplied to the image forming means, and transfers the clear image on both the faces of the recording medium only when it is judged that the detected residual amount secures an amount for transferring the clear image on both the faces of the recording medium. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine, and a process cartridge that can be attached to and detached from the image forming apparatus. The present invention relates to an image forming apparatus equipped with a printing function, a process cartridge that can be attached to and detached from the image forming apparatus, and a duplex printing control method.

2. Description of the Related Art In recent years, there is an image forming apparatus equipped with a double-sided printing function that enables image formation on the front and back surfaces of a recording medium such as recording paper. As technical documents filed earlier than the present invention, A developing device is provided in the revolver, and a first color visible image formed by sequentially superimposing toner images of respective colors on the photosensitive drum is transferred to a transfer belt that is in contact with the photosensitive drum, and further, the photosensitive drum A second color visible image is formed on the drum, and the recording medium is conveyed between the transfer belt on which the first color visible image is formed and the photosensitive drum on which the second color visible image is formed. There is an image forming apparatus equipped with a double-sided printing function for simultaneously transferring a visible image to the front and back surfaces of a recording medium (see, for example, Patent Document 1).
JP 2002-116679 A

  In general, the developer (toner) used in the developing device is stored in advance in the toner cartridge, and the toner is replenished from the toner cartridge to the developing device. When the toner in the developing device runs out, it becomes impossible to form an image. Therefore, in an image forming apparatus equipped with a double-sided printing function, a toner image to be transferred onto the surface of the recording medium and a toner image to be transferred onto the back surface of the recording medium are formed, and the two formed toner images are displayed on the surface of the recording medium. When it is determined that there is no toner at the time when the toner image for one side is formed when transferring to the back side, the image forming operation cannot be continued, and the toner image for one side formed previously is wasted. It will end up.

  The present invention has been made in view of the above circumstances, and image formation that prevents generation of useless toner by executing double-sided printing processing only when the amount of toner for double-sided printing is ensured. An object is to provide an apparatus, a process cartridge, and a duplex printing control method.

  In order to achieve this object, the present invention has the following features.

  An image forming apparatus according to the present invention includes a first image carrier, a second image carrier, a third image carrier, and an image forming unit that forms a visible image on the first image carrier. A first visible image formed on the first image carrier by the image forming means is transferred from the first image carrier to the second image carrier, and further from the second image carrier. The first visible image transferred to the third image carrier and transferred onto the third image carrier is transferred to one surface of the recording medium and formed on the first image carrier by the image forming means. The second visible image is transferred from the first image carrier to the second image carrier, and the second visible image transferred onto the second image carrier is transferred to the other surface of the recording medium. An image forming apparatus for transferring a visible image on both sides of a recording medium, the remaining amount of developer detected by the remaining amount of developer detected by the remaining amount of developer detected by the remaining amount of developer supplied to the image forming means Amount A double-sided transfer execution determination unit that determines whether or not the amount of the visible image transferred on both sides of the recording medium is secured; and a double-sided transfer execution determination unit that transfers the visible image to both sides of the recording medium And a double-sided transfer executing means for transferring the visible image to both sides of the recording medium only when it is determined that the amount of the recording medium is secured.

  In addition, the image forming apparatus according to the present invention provides a double-sided transfer to the recording medium when the double-sided transfer execution determining unit determines that the remaining amount does not secure an amount for transferring the visible image on both sides of the recording medium. It further has display means for displaying that printing cannot be executed.

  In addition, the image forming apparatus according to the present invention provides a double-sided transfer to the recording medium when the double-sided transfer execution determining unit determines that the remaining amount does not secure an amount for transferring the visible image on both sides of the recording medium. The information processing apparatus further includes a notification unit that notifies an external communication device that printing cannot be performed.

  The image forming apparatus according to the present invention is characterized in that at least the first image carrier, the image forming means, and the remaining developing amount detecting means are provided in a process cartridge that is detachable from the image forming apparatus main body. .

  Further, in the image forming apparatus according to the present invention, the development remaining amount detecting means includes means for detecting that the remaining amount of the developer supplied to the image forming means is less than a predetermined value, and the remaining amount is less than the predetermined value. A usage amount storage means for converting the usage amount of the developer used when the visible image is formed by the imaging means from the point of time, and accumulating the converted usage amount, and having a predetermined value or less The usage amount accumulated in the usage amount storage means is subtracted from the remaining amount of the developer at the time when the amount becomes the developer, and the remaining amount of the developer is detected.

  The image forming apparatus according to the present invention further includes a unit for detecting that the remaining amount of the developer supplied to the image forming unit is equal to or less than a second predetermined value, and the remaining amount is equal to or less than the second predetermined value. When the remaining amount becomes less than the predetermined value, the amount of developer used when the visible image is formed by the image forming means from when the remaining amount becomes less than the predetermined value is accumulated. Correction for calculating a correction coefficient when converting the usage amount of the developer accumulated and stored in the usage amount storage means from the time when the remaining amount becomes a predetermined value or less based on the usage amount of the developer accumulated until And a use amount storage unit that is used when a visible image is formed by the image forming unit from the time when the correction coefficient is calculated by using the correction coefficient calculated by the correction coefficient calculation unit. The amount of developer used is corrected, and the corrected amount of developer used is accumulated and stored. And it features.

  The image forming apparatus according to the present invention accumulates and stores the amount of developer used when the visible image is formed by the image forming unit until the remaining amount becomes a predetermined value or less. When converting the usage amount of the developer accumulated and stored in the usage amount storage means from the time when the remaining amount becomes the predetermined value or less based on the usage amount of the developer accumulated and stored until the time when it becomes the predetermined value or less Correction coefficient calculating means for calculating the correction coefficient of the image forming means, and the usage amount storage means forms a visible image by the image forming means from the time when the correction coefficient calculated by the correction coefficient calculating means falls below a predetermined value. The usage amount of the developer used at this time is corrected, and the corrected usage amount of the developer is accumulated and stored.

  The image forming apparatus according to the present invention further includes display means for displaying that the remaining amount of the developer has decreased when it is detected that the remaining amount of the developer has become a predetermined value or less. And

  The image forming apparatus according to the present invention further includes a notification unit that notifies an external communication device that the remaining amount of the developer has decreased when it is detected that the remaining amount of the developer has become a predetermined value or less. Furthermore, it is characterized by having.

  In the image forming apparatus according to the present invention, the double-sided transfer execution determining unit uses the developer used when the double-sided transfer image formed on the first image carrier is formed on the first image carrier. By determining whether or not the remaining amount detected by the remaining developing amount detecting means is greater than or equal to the amount of developer used predicted by the developer using amount predicting means, It is determined whether or not the remaining amount secures an amount for transferring the visible image on both sides of the recording medium, and the remaining amount detected by the developing remaining amount detecting means is predicted by the developer usage amount predicting means. When it is determined that the amount is greater than or equal to the usage amount of the agent, it is determined that the remaining amount is sufficient for transferring the visible image on both sides of the recording medium.

  The image forming apparatus according to the present invention includes a unit that detects that the remaining amount of the developer supplied to the image forming unit is equal to or less than a predetermined value, and a remaining amount of the developer that is supplied to the image forming unit. Means for detecting that the remaining amount is equal to or less than a second predetermined value, and a double-sided portion to be transferred to the recording medium from when the remaining amount becomes equal to or smaller than the second predetermined value until when the remaining amount becomes equal to or smaller than the predetermined value. The amount of developer used when the developed image is formed on the first image carrier is cumulatively stored, and based on the amount of stored developer used, both sides of the visible image transferred to the recording medium are recorded. Correction coefficient calculating means for calculating a correction coefficient used when predicting the usage amount of the developer used when the toner is formed on the first image carrier, and the developer usage amount prediction means, Both sides to be transferred to the recording medium using the correction coefficient calculated by the correction coefficient calculation means from the time when the value becomes equal to or less than the predetermined value. The visible and the corrected amount of the developer to be used when forming the first image bearing member, and wherein the predicting based on the amount that the corrected.

  In addition, the image forming apparatus according to the present invention includes a unit that detects that the remaining amount of the developer supplied to the image forming unit is equal to or less than a predetermined value, and records until the time when the remaining amount is equal to or less than the predetermined value. Accumulated storage of the developer usage when the two-sided visible image to be transferred onto the medium is formed on the first image carrier, and transfer to the recording medium based on the accumulated usage of the developer Correction coefficient calculating means for calculating a correction coefficient for predicting the usage amount of the developer used when the visible images for both surfaces formed on the first image carrier are further developed, The agent usage amount predicting unit forms a visible image on both sides to be transferred to the recording medium on the first image carrier using the correction coefficient calculated by the correction coefficient calculating unit from the time when the agent usage amount is below a predetermined value. The amount of developer used is corrected, and a prediction is made based on the corrected amount. .

  Further, the image forming apparatus according to the present invention is characterized in that the usage amount storage means is a contact type IC chip.

  The image forming apparatus according to the present invention is characterized in that the usage amount storage means is a non-contact type IC chip.

  The image forming apparatus according to the present invention is characterized in that the usage amount storage means is a contact type IC card.

  The image forming apparatus according to the present invention is characterized in that the usage amount storage means is a nonvolatile memory.

  The process cartridge according to the present invention detects an image carrier that holds a visible image, an image forming unit that forms a visible image on the image carrier, and a remaining amount of developer supplied to the image forming unit. A development cartridge remaining amount detection unit, and a process cartridge that is detachable from the main body of the image forming apparatus, wherein the development remaining amount detection unit has a remaining amount of developer supplied to the image forming unit equal to or less than a predetermined value. The amount of developer used and the amount of developer used when the visible image is formed by the image forming means from the time when the remaining amount becomes a predetermined value or less are converted, and the converted amount used is accumulated and stored. Use amount storage means, and subtract the use amount accumulated in the use amount storage means from the remaining amount of developer at the time when the amount falls below a predetermined value to detect the remaining amount of developer. It is characterized by.

  Further, the process cartridge according to the present invention has a means for detecting that the remaining amount of the developer supplied to the image forming means has become a second predetermined value or less, and the remaining amount has become a second predetermined value or less. The accumulated amount of developer used when a visible image is formed by the image forming means from the time when the remaining amount falls below the predetermined value is accumulated and stored until the remaining amount falls below the predetermined value. Correction coefficient for calculating a correction coefficient when converting the usage amount of the developer accumulated and stored in the usage amount storage means from the time when the remaining amount becomes the predetermined value or less based on the usage amount of the developer accumulated and stored in And a use amount storage unit that is used when a visible image is formed by the image forming unit from the time when the correction coefficient calculated by the correction coefficient calculation unit falls below a predetermined value. Corrects the amount of developer used and cumulatively stores the corrected amount of developer used And wherein the Rukoto.

  In addition, the process cartridge according to the present invention cumulatively stores the amount of developer used when the visible image is formed by the image forming means until the remaining amount becomes a predetermined value or less, and the remaining amount is predetermined. Based on the usage amount of developer accumulated and stored up to the time when the amount becomes less than or equal to the value, when converting the usage amount of developer accumulated and stored in the usage amount storage means from the time when the remaining amount becomes less than the predetermined value A correction coefficient calculating means for calculating a correction coefficient is further provided, and the usage amount storage means forms a visible image by the image forming means from the time when the predetermined value or less is reached, using the correction coefficient calculated by the correction coefficient calculating means. The usage amount of the developer used at the time is corrected, and the corrected usage amount of the developer is accumulated and stored.

  The process cartridge according to the present invention is characterized in that the usage amount storage means is a contact type IC chip.

  The process cartridge according to the present invention is characterized in that the usage amount storage means is a non-contact type IC chip.

  The process cartridge according to the present invention is characterized in that the used amount storage means is a contact type IC card.

  The process cartridge according to the present invention is characterized in that the usage amount storage means is a nonvolatile memory.

  The double-sided printing control method according to the present invention includes a first image carrier, a second image carrier, a third image carrier, and an image forming unit that forms a visible image on the first image carrier. And the first visible image formed on the first image carrier by the image forming means is transferred from the first image carrier to the second image carrier, and further from the second image carrier. The first visible image transferred onto the third image carrier and transferred onto the third image carrier is transferred to one surface of the recording medium and formed on the first image carrier by the image forming means. Transferring the second visible image from the first image carrier to the second image carrier, and transferring the second visible image transferred onto the second image carrier to the other surface of the recording medium; Double-sided printing in an image forming apparatus having a transfer unit that transfers a visible image on both sides of a recording medium, a development remaining amount detection unit that detects a remaining amount of developer supplied to the image forming unit, and a control unit In this method, the control means determines whether or not the remaining amount detected by the developing remaining amount detecting means secures an amount for transferring the visible image on both sides of the recording medium. The transfer means transfers the visible image onto both sides of the recording medium only when the remaining amount is determined to be sufficient for transferring the visible image on both sides of the recording medium by the step and the double-sided transfer execution judging step. And performing a double-sided transfer execution step.

  In the double-sided printing control method according to the present invention, the image forming apparatus further includes a display unit, and when the control unit transfers the visible image on both sides of the recording medium in the double-sided transfer execution determination step. When it is determined that the amount is not secured, a display step of displaying on the display unit that double-sided printing on the recording medium cannot be performed is further performed.

  In the double-sided printing control method according to the present invention, the image forming apparatus further includes a communication unit that transmits / receives information to / from an external communication device, and the control unit performs a double-sided transfer execution determination step so that the remaining amount is a recording medium. A notification step of notifying the external communication device by the communication means that double-sided printing on the recording medium cannot be performed when it is determined that the amount for transferring the visible image on both sides of the recording medium is not secured. It is characterized by.

  In the double-sided printing control method according to the present invention, the development remaining amount detection means is less than the predetermined value with the means for detecting that the remaining amount of the developer supplied to the image forming means is less than the predetermined value. And a usage amount storage means for storing the developer remaining amount and the developer usage amount at the time of development. A usage amount storage step of converting the usage amount of the developer used when the visible image is formed by the image forming means and accumulatively storing the converted usage amount in the usage amount storage means. And the amount of developer accumulated in the usage amount storage means is subtracted from the remaining amount of developer at the time when the predetermined amount or less is stored in the usage amount storage means, and the remaining amount of developer is detected. And a detection step.

  In the double-sided printing control method according to the present invention, the remaining developing amount detecting means includes means for detecting that the remaining amount of the developer supplied to the image forming means is equal to or less than a second predetermined value, and the remaining amount. The usage amount of the developer used when the visible image is formed by the image forming means from the time when the remaining amount becomes less than the second predetermined value to the time when the remaining amount becomes less than the predetermined value is accumulated in the usage amount storage means. Based on the usage amount of the developer accumulated and stored in the usage amount storage unit until the remaining amount becomes equal to or less than the predetermined value, the accumulated amount is stored in the usage amount storage unit from the time when the remaining amount becomes equal to or less than the predetermined value. Correction coefficient calculation means for calculating a correction coefficient when converting the amount of developer used, and the development remaining amount detection means performs correction when it is detected that the amount is less than a predetermined value. Used when a visible image is formed by the image creation means using the correction coefficient calculated by the coefficient calculation means The amount of the developer is corrected to be, characterized by accumulatively stored in the usage storage means the amount of developer the correction.

  Also, the double-sided printing control method according to the present invention accumulates the usage amount of the developer used when the visible image is formed by the imaging means until the remaining amount becomes a predetermined value or less in the usage amount storage means. Based on the usage amount of the developer accumulated and stored in the usage amount storage unit until the remaining amount becomes equal to or less than the predetermined value, the accumulated amount is stored in the usage amount storage unit from the time when the remaining amount becomes equal to or less than the predetermined value. Correction coefficient calculation means for calculating a correction coefficient for converting the amount of developer used, and the development remaining amount detection means calculates the correction coefficient when it is detected that the amount is less than a predetermined value. Using the correction coefficient calculated by the means, the usage amount of the developer used when the visible image is formed by the image forming means is corrected, and the corrected usage amount of the developer is accumulated and stored in the usage amount storage means. It is characterized by that.

  In the double-sided printing control method according to the present invention, the development remaining amount detecting means indicates that the remaining amount of the developer has decreased when the remaining amount of the developer has been detected to be a predetermined value or less. Further, a display step of displaying on is performed.

  Further, in the double-sided printing control method according to the present invention, when the remaining developing amount detecting means detects that the remaining amount of the developer is equal to or less than the predetermined value, the communication means notifies that the remaining amount of the developer has decreased. Further, a notification step of notifying an external communication device is further performed.

  In the double-sided printing control method according to the present invention, the double-sided transfer execution determination step is performed when the control unit forms a visible image of both sides to be transferred to the recording medium on the first image carrier by the transfer unit. Performs a developer usage amount prediction step for predicting the usage amount of the developer used, and the remaining amount detected by the development remaining amount detection means is the developer usage amount predicted by the control means in the developer usage amount prediction step. By determining whether or not it is above, the control unit determines whether or not the remaining amount secures an amount for transferring the visible image on both sides of the recording medium, and is detected by the developing remaining amount detecting unit. When the control means determines that the remaining amount is equal to or greater than the developer usage amount predicted by the control means in the developer usage amount prediction step, the remaining amount is the amount when the visible image is transferred to both sides of the recording medium. It is characterized by determining that it has secured.

  Further, the double-sided printing control method according to the present invention includes a means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less, and a remaining amount of developer supplied to the image forming means. Means for detecting that the remaining amount is equal to or less than the second predetermined value, and both sides transferred to the recording medium from the time when the remaining amount becomes equal to or less than the second predetermined value to the time when the remaining amount becomes equal to or less than the predetermined value. The amount of developer used when a minute image is formed on the first image carrier is accumulated, and based on the amount of accumulated developer used, the image on both sides transferred to the recording medium is obtained. Correction coefficient calculating means for calculating a correction coefficient for predicting the usage amount of the developer used when formed on the first image carrier, and the developer usage amount prediction step includes a predetermined amount. When it is detected that the value is less than or equal to the value, the control means uses the correction coefficient calculated by the correction coefficient calculation means to And correcting the usage amount of the developer used when the visible images of both sides transferred to the first image carrier are formed on the first image carrier, and predicting based on the corrected usage amount of the developer. And

  Further, the double-sided printing control method according to the present invention includes a means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less, and a point in time until the remaining amount becomes a predetermined value or less. The developer usage amount is accumulated when the visible images for both sides to be transferred to the recording medium are formed on the first image carrier, and the developer usage amount is transferred to the recording medium based on the accumulated developer usage amount. Correction coefficient calculation means for calculating a correction coefficient for predicting the usage amount of the developer used when forming the visible images for both surfaces on the first image carrier, and the developer In the usage amount predicting step, when it is detected that the value is less than or equal to the predetermined value, the control means uses the correction coefficient calculated by the correction coefficient calculation means to display the first and second visible images transferred to the recording medium. The amount of developer used when formed on the image carrier is corrected, and the corrected amount of developer used is corrected. Characterized by predicting the.

  The image forming apparatus and the double-sided printing control method according to the present invention include a first image carrier, a second image carrier, a third image carrier, and an operation for forming a visible image on the first image carrier. A first visible image formed on the first image carrier by the imaging means, and transferred from the first image carrier to the second image carrier, The first visible image transferred from the image carrier to the third image carrier and transferred onto the third image carrier is transferred to one surface of the recording medium, and the first image is formed by the image forming means. The second visible image formed on the carrier is transferred from the first image carrier to the second image carrier, and the second visible image transferred on the second image carrier is transferred to the other side of the recording medium. In the image forming apparatus that transfers the developed image to both sides of the recording medium and transfers the visible image on both sides of the recording medium, the remaining amount of the developer supplied to the image forming means is detected, and the detected remaining amount is visualized on both sides of the recording medium. Roll It is to transfer the visible image on both surfaces of the recording medium only when it is determined that the reserved amount at the time of, it is possible to prevent the occurrence of waste toner in advance.

  The process cartridge according to the present invention detects an image carrier that holds a visible image, an image forming unit that forms a visible image on the image carrier, and a remaining amount of developer supplied to the image forming unit. A development cartridge remaining amount detecting unit that is detachable from the image forming apparatus and detects that the remaining amount of developer supplied to the image forming unit is less than a predetermined value. When the amount of developer used when a visible image is formed by the image forming means is converted from the time when the value becomes equal to or less than the predetermined value, the converted amount used is accumulated and stored, and when the value becomes equal to or less than the value By subtracting the accumulated usage amount from the remaining amount of developer at, and detecting the remaining amount of developer, the image forming apparatus transfers the developed image on both sides of the recording medium with the detected remaining amount. Only when it is determined that the amount of Will be transferred, it is possible to prevent useless toner in advance.

  The image forming apparatus according to the present invention includes a first image carrier (1), a second image carrier (10), a third image carrier (100), and a first image carrier (1). Image forming means (2, L, 3, 5, 4) for forming a visible image on the first image carrier (1) by the image forming means (2, L, 3, 5, 4). The first visible image formed above is transferred from the first image carrier (1) to the second image carrier (10), and further from the second image carrier (10) to the third image. The first visible image transferred to the carrier (100) and transferred onto the third image carrier (100) is transferred to one surface of the recording medium (P), and image forming means (2, L, Transferring the second visible image formed on the first image carrier (1) by 3, 5, 4) from the first image carrier (1) to the second image carrier (10); Recording the second visible image transferred on the second image carrier (10) An image forming apparatus that transfers the image onto the other surface of the body (P) and transfers the visible image onto both surfaces of the recording medium (P), and is supplied to the image forming means (2, L, 3, 5, 4). Only when the remaining amount of the agent is detected and it is determined that the detected remaining amount secures the amount for transferring the visible image on both sides of the recording medium (P), the both sides of the recording medium (P) are detected. By transferring the visible image, it is possible to prevent generation of useless toner.

Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings.
First, a schematic configuration of an image forming apparatus according to the present invention will be described with reference to FIG. FIG. 1 suggests a schematic cross-sectional view of an image forming apparatus equipped with a double-side transfer function capable of simultaneously forming images on both sides of a recording medium.

  The image forming apparatus according to the present invention supports a photosensitive drum (1), which is a first image carrier, so as to be rotatable, and a plurality of units ((a), (b), (c), (d )). The photosensitive drums (1) are provided side by side, and on each outer peripheral portion of each photosensitive drum (1), a static eliminating device (L), a cleaning device (2), and a charging device (3) are provided. ) And a developing device (5). An exposure device (4) is provided below the photosensitive drum (1), and optical information emitted from the exposure device (4) is transmitted between the charging device (3) and the developing device (5). The photosensitive drum (1) is irradiated at the writing position. The developing device (5) provided on the photosensitive drum (1) is configured such that the color of the developer (toner) varies depending on the photosensitive drum (1).

  The photosensitive drum (1) as the first image carrier is composed of a photosensitive member in which an organic semiconductor layer as a photoconductive substance is provided on the surface of an aluminum cylinder having a diameter of about 30 mm to 100 mm. A part of the photosensitive drum (1) is disposed so as to be in contact with the intermediate transfer belt (10) as the second image carrier. It is also possible to apply a belt-shaped photoconductor instead of the drum-shaped photoconductor.

  The intermediate transfer belt (10) as the second image carrier is supported and stretched by the rotating rollers (11, 12, 13), and moves in the direction of the arrow shown in FIG. 1 (counterclockwise). . Incidentally, on the back side (inside the belt loop) of the intermediate transfer belt (10) that is the second image carrier, the first transfer means (20) is the photosensitive drum (1) that is the first image carrier. It is deployed in the vicinity. A cleaning device (25) for the intermediate transfer belt, which is the second image carrier, is provided on the front side (outside of the belt loop) of the intermediate transfer belt (10), which is the second image carrier. After the toner image on the intermediate transfer belt (10) which is the second image carrier is transferred, unnecessary toner remaining on the surface of the intermediate transfer belt (10) is wiped off. The intermediate transfer belt (10), which is the second image carrier, is composed of a resin film having a substrate thickness of 50 μm to 600 μm, or a belt having a rubber substrate, and is a first image carrier. It has a resistance value capable of transferring a toner image from the drum (1).

  The exposure device (4) irradiates the uniformly charged surface of the photosensitive drum (1) as a latent image with optical information corresponding to full-color image formation using a laser system. An exposure apparatus composed of an LED array and an imaging device can also be applied.

  A third image carrier (100) is disposed on the right side of the intermediate transfer belt (10), which is the second image carrier, and the third image carrier (100) is rotated. It is supported and stretched by the rollers (111, 112, 113) and moves in the direction of the arrow shown in FIG. 1 (clockwise). A second transfer means (120) is provided on the back side (inside the belt loop) of the third image carrier (100), and the front side (belt loop) of the third image carrier (100). The third image bearing member cleaning device (250), charger (CH), and the like are arranged outside. The cleaning device (250) wipes off unnecessary toner remaining on the third image carrier (100) after the third image carrier (100) transfers the toner image onto the recording medium (P). It will be.

  The third image carrier (100) includes a second transfer means (120), a rotation roller (113), and a rotation roller (10) that supports the intermediate transfer belt (10) as the second image carrier. 11) makes contact with the intermediate transfer belt (10), which is the second image carrier, to form a transfer nip.

  The third image carrier (intermediate transfer member) (100) is composed of a resin film having a substrate thickness of 50 μm to 600 μm or a belt based on rubber, and this belt is the second image carrier. It has a resistance value that enables a toner image to be transferred from an intermediate transfer belt (10).

  A paper feeding device (paper feeding cassette) (26-1, 26-2) is provided below the image forming apparatus, and the paper feeding device (paper feeding cassette) (26-1, 26-2) is provided in the lower part of the image forming apparatus. A recording medium (P) such as paper is stored. Then, the recording medium (P) at the top of the sheet feeding device (sheet feeding cassette) (26-1, 26-2) is moved one by one by the sheet feeding roller (27), and a plurality of transport guides (29) are moved. Then, it is conveyed to the registration roller pair (28).

  In the upper part of the image forming apparatus, a fixing heating means (30), a paper discharge guide pair (31), a paper discharge roller pair (32), and a paper discharge stack section (40) are arranged. ing.

  Further, a toner storage section (TS) that can store replenishment toner is provided between the intermediate transfer belt (10) that is the second image carrier and the paper discharge stack section (40). There are four colors of toner stored in the toner storage section (TS): magenta (M), cyan (C), yellow (Y), and black (BK). The toner storage section is in the form of a cartridge (TC). (TS). The toner is appropriately supplied to the corresponding toner color developing device (5) by toner supply means such as a powder pump (not shown).

  Note that a part of the frame (50) of the main body of the image forming apparatus has a structure that can be rotated and opened around the opening / closing support shaft (50A), so that the conveyance path of the recording medium (P) is large. A structure that facilitates processing of the opened and jammed recording medium (P) is constructed.

(Processing operation in image forming apparatus)
Next, a processing operation at the time of duplex printing in the image forming apparatus having the above configuration will be described.

First, an image forming process is performed on the photosensitive drum (1) which is the first image carrier.
This image forming process is performed by a first image carrier in which light from an LD light source (not shown) is uniformly charged by a charging device (3) through an optical component (not shown) by an exposure device (4). Among the photosensitive drums (1), the electrostatic latent image corresponding to the writing information (information corresponding to the color) is irradiated on the photosensitive drum (1) in FIG. Will be formed.

  The electrostatic latent image formed on the photosensitive drum (1), which is the first image carrier in FIG. 1A, is developed by the developing device (5), and a visible image with toner is formed on the photosensitive drum ( It is formed and held on the surface of 1). The toner image formed and held on the photosensitive drum (1) is an intermediate image which is a second image carrier that moves in synchronization with the photosensitive drum (1) by the first transfer means (20). It is transferred onto the surface of the transfer belt (10). Then, the toner remaining on the surface of the photosensitive drum (1) is removed by the cleaning device (2), and then the photosensitive drum (1) is neutralized by the static eliminator (L) to prepare for the next image forming cycle. become.

  Next, the intermediate transfer belt (10) as the second image carrier is shown in FIG. 1 while carrying the visible image transferred onto the surface of the intermediate transfer belt (10) by the photosensitive drum (1). It moves in the direction of the arrow (counterclockwise). Note that an electrostatic latent image corresponding to another color is written on the photosensitive drum (1) of FIG. 1B, and a developed image developed with toner of the corresponding color is formed. become. Then, the visible image formed on the photosensitive drum (1) in FIG. 1 (b) is superimposed on the visible color image carried on the intermediate transfer belt (10) as the second image carrier. Finally, a four-color superimposed visible image is formed on the intermediate transfer belt (10) through the photosensitive drum (1) shown in FIGS.

  At this time, the third image carrier (100) moves in the direction of the arrow (clockwise) shown in FIG. 1 in synchronization with the intermediate transfer belt (10) as the second image carrier. By the action of the second transfer means (120), the superimposed visible image formed on the surface of the intermediate transfer belt (10) which is the second image carrier is transferred to the surface of the third image carrier (100). It will be.

  This transfer method is called a so-called tandem transfer method, and is performed on the four photosensitive drums (1) (a), (b), (c), and (d) shown in FIG. In this way, an image forming process can be performed while the intermediate transfer belt (10), which is the second image carrier, and the third image carrier (100) are moved while the image is formed in Therefore, it is possible to shorten the image forming time.

  Next, when the intermediate transfer belt (10), which is the second image carrier, moves to a predetermined position, the toner image to be formed on the other surface of the recording medium (P) is again formed in the above processing steps. Then, an image is formed by the photosensitive drum (1) which is the first image carrier, and at that time, paper feeding is started.

  When paper feeding is started, the paper feeding roller (27) rotates counterclockwise, and the recording medium (26-1 and 26-2) in the uppermost part in the paper feeding device (paper feeding cassette) (26-1, 26-2). P) is pulled out and conveyed to the registration roller pair (28). When the recording medium (P) is conveyed between the intermediate transfer belt (10) as the second image carrier and the third image carrier (100) through the registration roller pair (28). The toner image on the surface of the intermediate transfer belt (10), which is the second image carrier, is transferred onto one surface of the recording medium (P) by the second transfer means (120).

  The recording medium (P) is further conveyed upward, and the toner image on the surface of the third image carrier (100) is transferred to the other surface of the recording medium (P) by the charger (CH). become. At the time of these transfers, the recording medium (P) is conveyed at a timing so that the transfer position of the image onto the recording medium (P) is not shifted.

  In this embodiment, the polarity of the toner imaged on the photosensitive drum (1) which is the first image carrier is negative. Then, by applying a positive charge to the first transfer means (20), the toner image formed on the photosensitive drum (1), which is the first image carrier, becomes the second image carrier. Is transferred onto the intermediate transfer belt (10). Then, by applying a positive charge to the second transfer means (120), the toner image formed on the intermediate transfer belt (10), which is the second image carrier, becomes the third image carrier. (100) to be transferred. Further, the toner image on the surface of the intermediate transfer belt (10) as the second image carrier is transferred to one surface of the recording medium (P). Further, by applying a positive polarity charge from the charger (CH), a negative polarity toner image on the surface of the third image carrier (100) is sucked onto the recording medium (P), and the recording medium (P). A toner image is transferred to the other surface of the toner.

  Then, the recording medium (P) on which the toner images are transferred on both sides by the processing operation described above is conveyed to the fixing heating means (30), and the toner images on both sides of the recording medium (P) are melted and fixed at once. Then, after passing through the paper discharge guide pair (31), the paper is discharged to the paper discharge stack part (40) at the upper part of the main body frame by the paper discharge roller pair (32).

  The image formed on both sides of the recording medium (P) by the image forming apparatus in this embodiment is a surface (page) to be transferred to the recording medium (P) later, that is, a second image carrier. In order to align the pages, the surface (page) directly transferred from the intermediate transfer belt (10) to the recording medium (P) becomes the lower surface and is placed on the paper discharge stack section (40). The second image is created first, the toner image is held on the third image carrier (100), and the image on the first page is transferred to the intermediate transfer belt (10) as the second image carrier. And transferred directly onto the recording medium (P). For example, on the third image carrier (100), a visible image is formed in the order of the first sheet-back side, second sheet-back side of the read document, and transferred to one surface of the recording medium (P). At the same time, on the second image carrier (10), a visible image is formed in the order of the first sheet-front, second sheet-front of the read document, and transferred to the other surface of the recording medium (P). Will be. In addition, the transfer to the recording medium (P) is performed for the first original document read-back held by the third image carrier (100) and the first original read document held by the second image carrier (10). -The recording medium (P) is conveyed and transferred so as to coincide with the front. Normally, the first control unit that controls the image forming apparatus recognizes that the image data of the second-read document has been stored in an image memory (not shown) included in the image forming apparatus, and then the first By starting the image forming operation on the image carrier, continuous transfer of two pages on the recording medium (P) at the same time on both sides can be performed. -The image forming time can be shortened by performing the first image-back image forming operation in advance while reading the back image data.

  The image transferred from the intermediate transfer belt (10) as the second image carrier to the recording medium (P) becomes a normal image on the surface of the photosensitive drum (1) as the first image carrier. As described above, the toner image transferred from the third image carrier (100) to the recording medium (P) is a reverse image (mirror image) on the surface of the photosensitive drum (1) as the first image carrier. It will be exposed to become. Such an image forming order for page alignment is a known technique for storing image data in a memory (not shown) provided in the image forming apparatus, and exposure for switching between a normal image and a reverse image (mirror image). Can also be realized by a known image processing technique.

  The cleaning device (250) including a brush roller, a collection roller, a blade, and the like transfers the toner image from the third image carrier (100) to the recording medium (P), and then transfers the third image carrier ( 100), unnecessary toner and paper dust remaining on the surface are removed.

  Further, the cleaning device (250) is configured to be swingable about the cleaning swing support point (250A), and a state in which the brush roller can contact and separate from the surface of the third image carrier (100) is constructed. doing. Before the transfer to the recording medium (P), when the third image carrier (100) carries a toner image, the brush roller is separated from the third image carrier (100) and needs to be cleaned. In this case, the cleaning device (250) is swung counterclockwise to bring the brush roller into contact with the third image carrier (100). The unnecessary toner removed by the cleaning device (250) is collected in the toner storage unit (250B).

  Next, the functional configuration when controlling the image forming apparatus having the above configuration will be described with reference to FIG.

  An image forming apparatus according to the present invention includes an overall control unit (201), a reading control unit (202), an image formation control unit (203), a paper conveyance control unit (204), and a fixing control unit (205). And an operation control unit (206), a toner usage amount storage unit (207), a toner remaining amount detection unit (208), and an image storage unit (209). Each function will be described below.

  The overall control unit (201) is a part that controls the entire image forming apparatus. Based on input information from the operation control unit (206), a reading control unit (202), an image formation control unit (203), and the like. The image forming operation is realized by operating the paper conveyance control unit (204), the fixing control unit (205), and the toner remaining amount detection unit (208).

  The reading control unit (202) is a part that controls the reading process of the original, reads the original with various settings such as a predetermined magnification, resolution, and color, and stores the read image data in the image storage means (209). Will do.

  The image formation control unit (203) is a part that controls the process of forming an image of the image data stored in the image storage means (209) on the first image carrier, and the image storage means (209). The stored image data is read out, and based on the read-out image data, the photosensitive drum that is the first image carrier is exposed to form an electrostatic latent image. The image formation control unit (203) counts the number of exposure dots of the exposed image data every time the first image carrier is exposed according to an instruction from the overall control unit (201). The total number of exposure dots of the counted image data is notified to the overall control unit (201).

  The paper conveyance control unit (204) is a part that controls conveyance of the recording medium (P) such as recording paper, and a visible image is transferred onto the conveyed recording medium (P). The fixing control unit (205) is a part that controls processing for fixing the visible image transferred to the recording medium (P) to the recording medium (P).

  The operation control unit (206) is a part that controls operations when forming an image such as various settings related to reading of a document and various settings related to printing processing, and is input from a display unit included in the image forming apparatus. The input information is notified to the overall control unit (201). Further, information notified from the overall control unit (201) is displayed on the display unit.

  The toner usage amount storage means (207) is a portion for storing the usage amount of toner used when forming a visible image on the recording medium (P). The toner usage amount storage means (207) is not particularly limited as long as the signal information can be stored in a rewritable manner. For example, the toner usage amount storage means (207) is an electrical unit such as a RAM or a rewritable ROM. A storage means, a magnetic storage means such as a magnetic recording medium or a magneto-optical memory, and the like are applicable. In view of ease of handling and cost, it is preferable to apply a nonvolatile storage means.

  The toner remaining amount detecting means (208) is a portion for detecting the remaining amount of toner remaining in the developing device (5) shown in FIG. The toner remaining amount detecting means (208) is not particularly limited as long as it can detect that the remaining amount of toner is equal to or less than a predetermined threshold value. For example, the toner remaining amount detecting means (208) detects the toner concentration. Functions, functions that detect toner capacity, functions that use a magnetic sensor, functions that detect the weight of toner, light transmission functions, and the like can be applied. .

  The image storage means (209) is a part for storing image data to be formed on the recording medium (P).

(Double-sided printing process in the first embodiment)
Next, the double-sided printing process in this embodiment will be described with reference to FIG.
First, when a command for executing double-sided printing is notified from the operation control unit (206) to the overall control unit (201), the overall control unit (201) notifies the remaining toner amount detection unit (208) of the remaining amount of toner. The detection process is executed. The toner remaining amount detecting means (208) detects the remaining amount of toner and notifies the overall control unit (201) of the detected remaining toner amount (M). Then, the overall control unit (201) has the toner remaining amount (M) detected by the toner remaining amount detecting means (208) smaller than the predetermined threshold value (A) or the same value as the threshold value (A). It is determined whether or not (M ≦ A) (step S1).

  If the overall control unit (201) determines that the remaining toner amount (M) is greater than the predetermined threshold value (A) by this determination (step S1 / NO), the overall control unit (201) The control unit (202) is caused to execute a document reading process, and a duplex printing process is performed (step S2).

  First, the reading control unit (202) performs a document reading process, and read image data for both sides read by the reading control unit (202) (surface image data printed on the surface of the recording paper, back surface of the recording paper) The back side image data to be printed on is stored in the image storage means (209). Next, the overall control unit (201) causes the image formation control unit (203) to execute an image formation process. Further, the overall control unit (201) causes the paper conveyance control unit (204) to execute paper conveyance control. In addition, the fixing control unit (205) is caused to execute fixing processing.

  Then, the image formation control unit (203) is based on the image data stored in the image storage means (209) (front surface image data printed on the front surface of the recording paper, back surface image data printed on the back surface of the recording paper). In addition, an image data image forming process is performed on the first image carrier. In this image forming process, first, an image of the back surface image data stored in the image storage means (209) is formed on the first image carrier, and then the front surface stored in the image storage means (209). An image of image data is formed on the first image carrier. As a result, the image of the back surface image data formed on the first image carrier is transferred onto the second image carrier and further transferred onto the third image carrier. Further, the image of the surface image data created on the first image carrier is transferred onto the second image carrier. Then, the back image data image transferred to the third image carrier is transferred to one side of the recording paper, and the front image data image transferred to the second image carrier is recorded. It will be transferred to the other side of the paper.

  Next, the overall control unit (201) causes the remaining toner amount detection means (208) to execute the remaining toner amount detection process again, and the remaining toner amount detection means (208) detects the remaining amount of toner, and The detected toner remaining amount (M) is notified to the overall control unit (201). The overall control unit (201) determines whether the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is less than or equal to a predetermined threshold value (A), If it is determined that the remaining amount of toner is greater than the predetermined threshold (A) (step S1 / NO), the above processing operation is repeated (steps S1 to S2).

  When the overall control unit (201) determines that the remaining toner amount (M) is smaller than the predetermined threshold value (A) or the same value as the threshold value (A) (M ≦ A) (Step S1 / YES), the overall control unit (201) performs the toner near-end mode duplex printing process. Then, the overall control unit (201) causes the operation control unit (206) to execute a process of giving a toner near-end warning to notify the user that the remaining amount of toner is low (step S3). As a result, the operation control unit (206) displays a toner near-end warning as shown in FIG. 4 on the display unit of the image forming apparatus. The toner near-end warning can be notified to the user by voice, or can be notified to the user by blinking a lamp. The toner near-end mode indicates a double-sided printing process (the following process) that is performed when the remaining amount of toner is low.

  Next, the overall control unit (201) causes the reading control unit (202) to execute a document reading process in order to perform a double-sided printing process (step S4). Then, the reading control unit (202) performs a document reading process, and, similarly to the above, read image data for both sides read by the reading control unit (202) (surface image data printed on the surface of the recording paper). , Back side image data printed on the back side of the recording paper) is stored in the image storage means (209). Next, the overall control unit (201) causes the image formation control unit (203) to execute image formation processing in the toner near-end mode, and the image formation control unit (203) is stored in the image storage unit (209). Based on the obtained image data (front image data printed on the front surface of the recording paper, back image data printed on the back surface of the recording paper), image data is processed on the first image carrier. The image of the back surface image data stored in the image storage means (209) is formed on the first image carrier, and then the image of the surface image data stored in the image storage means (209) is the first image carrier. The image is formed on the image carrier.

  At this time, the image formation control unit (203) counts the number of exposure dots of the image data to be written on the first image carrier each time an image of the image data is formed on the first image carrier. The total number of exposure dots is notified to the overall control unit (201) (step S5). As a result, the image forming control unit (203) counts the number of exposure dots of the back surface image data to be formed on the first image carrier, and the total number of exposure dots of the back surface image data is controlled by the overall control unit (201). Notify The image formation control unit (203) counts the number of exposure dots of the surface image data to be imaged on the first image carrier, and the total number of exposure dots of the surface image data thus counted is the overall control unit (201). Will be notified.

  Then, the overall control unit (201) uses the number of exposure dots (B) of the image data notified from the image formation control unit (203) and the standard toner usage (D) per dot. The toner usage amount (N) used for the printing process is calculated by the following equation (1) (step S6).

Formula (1)
N (g) = B (g / dot) × D (dot)
N: amount of toner used B: number of exposure dots of image data D: standard amount of toner used per dot

  The overall control unit (201) stores the toner usage amount (N) calculated by the above equation (1) in the toner usage amount storage unit (207), and the toner usage amount storage unit (207) stores the toner usage amount. (N) is accumulated (step S7).

  Thereby, the overall control unit (201) first determines the amount of toner used when the image of the back surface image data is formed based on the number of exposure dots of the back surface image data notified from the image forming control unit (203). The calculated toner usage amount of the back surface image data is stored in the toner usage amount storage means (207). Further, the overall control unit (201) calculates the amount of toner used when the image of the surface image data is formed based on the number of exposure dots of the surface image data notified from the image formation control unit (203). The calculated toner usage amount of the surface image data is stored in the toner usage amount storage means (207).

  Next, the overall control unit (201) reads the double-sided read image data (surface image data (P1) printed on the front surface of the recording paper, the back surface printed on the back surface of the recording paper). The image data (P2)) is taken out from the image storage means (209), and the estimated toner usage (N ′) printed on the next recording paper from the total number of dots (P1, P2) of the read image data for both sides taken out. ) Is predicted by the following equation (2) (step S8).

Formula (2)
N ′ (g) = D (g / dot) × (P1 (dot) + P2 (dot))
N ′: Estimated amount of toner used D: Standard amount of toner used per dot P1: Number of dots in front surface image data P2: Number of dots in back surface image data

  Next, the overall control unit (201) reads out the toner usage amount (U) accumulated in the toner usage amount storage means (207) and the maximum toner amount (C) that can be printed after shifting to the toner near mode. The current toner remaining amount (Z) is calculated by the following equation (3) (step S9).

Formula (3)
Z (g) = C (g) -U (g)
Z: current toner remaining amount C: maximum toner amount that can be printed after shifting to toner near mode U: toner usage amount accumulated in toner usage amount storage means

  Then, the overall control unit (201) compares the current toner remaining amount (Z) calculated by the above formula (3) with the estimated toner usage (N ′) used for the next double-sided printing process. It is then determined whether or not the next double-sided printing process is possible (step S10). In this determination, the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is larger than the current toner remaining amount (Z) (N ′> Z). ) (Step S10 / YES) determines that the next double-sided printing process is impossible, and the overall control unit (201) causes the operation control unit (206) to execute a warning process without toner (Step S11). Then, a display indicating that the double-sided printing process cannot be performed is displayed on the display unit included in the image forming apparatus, and the double-sided printing process is prohibited.

  When the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is less than or equal to the current toner remaining amount (Z) (Z ≧ N ′) ) (Step S10 / NO), it is determined that the next double-sided printing process is possible, and the overall control unit (201) causes the image forming control unit (203) to execute the double-sided printing process control. This process is repeated (steps S4 to S10).

  As described above, in the first embodiment, when the double-sided printing process is executed, the remaining toner amount is detected by the toner remaining amount detecting unit, and the toner near-mode printing process is performed based on the detected remaining toner amount. It is determined whether or not to shift to. When the toner near mode is entered, the amount of toner used for double-sided printing is predicted, and the remaining amount of toner used for double-sided printing is secured based on the predicted amount of toner used Only the double-sided printing process is executed. As a result, the amount of toner used for double-sided printing is grasped in advance, and only when it is determined that double-sided printing is possible, the double-sided printing process is executed. If it is ensured, the double-sided printing process is not executed, and the wasteful transfer process can be prevented in advance, and the toner can be used effectively.

  Further, since unnecessary transfer processing is prevented in advance, it is not necessary to perform control for removing the transferred toner image, the load on the cleaning device can be reduced, and power consumption is not wasted. It will be.

  In the first embodiment, the toner usage amount accumulated in the toner usage amount storage means (207) when shifting to the toner near mode is the first image from the exposure device (4) shown in FIG. It is also possible to measure the exposure time written on the carrier, and to calculate using the measured exposure time and the amount of toner used per unit exposure time.

  For example, the exposure time of the laser emitted from the exposure device (4) onto the first image carrier is counted by the number of clock pulses, and the counted value is used as the exposure time. Then, the toner usage is calculated using the counted value and the toner usage per unit count. As a result, the multi-level signal that increases the exposure time corresponding to one dot of the laser for the high-density portion of the image and shortens the exposure time corresponding to one dot for the intermediate-density portion of the image is also an image signal. It becomes possible to use as.

  Further, the exposure time of the laser emitted from the exposure device (4) onto the first image carrier is not counted, but the toner image is formed in the non-exposed portion of the laser by counting the non-exposure time of the laser. The present invention can also be applied to a development system apparatus.

Next, a second embodiment will be described.
The second embodiment is applied when the number of exposure dots used when calculating the amount of toner used for double-sided printing is integrated before shifting to the toner near mode, and when shifting to the toner near mode. The standard amount of toner used per dot is corrected based on the accumulated number of exposure dots. In general, even when an image is formed on the first image carrier with the same image signal, various factors (for example, variations in components forming the image, user usage environment, temperature change and humidity change in the apparatus) Etc.) causes variations in the amount of toner adhering to the first image carrier. In the second embodiment, a correction coefficient is calculated based on the number of exposure dots accumulated before shifting to the toner near mode, and variations due to various factors can be corrected by using the calculated correction coefficient. Thus, it is possible to perform more accurate detection processing of the remaining amount of toner. The processing operation in the second embodiment will be described below. The image forming apparatus shown in FIG. 1 is appropriately applied from the cartridge (TC) disposed in the toner storage unit (TS) to the corresponding toner color developing device (5) by a toner supply unit such as a powder pump (not shown). In order to carry out the present embodiment, the second threshold value (E) having a value larger than a predetermined threshold value (A) for determining whether or not to shift to the toner near mode is used. (A <E), and the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than or equal to the second threshold value (E). The image control unit (203) counts the number of exposure dots, and stores the counted number of exposure dots in the toner usage amount storage means (207). Then, the image forming control unit (203) until the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than or equal to the first threshold value (A). The counted number of exposure dots is stored in the toner usage amount storage means (207), and the correction coefficient (F) is calculated by the following equation (4) based on the number of exposure dots accumulated in the toner usage amount storage means (207). Will be calculated.

Formula (4)
G (g / dot) = (H (g) -C (g)) / I (dot)
F = G (g / dot) / D (g / dot)
G: amount of toner used per dot before transition to toner near mode (from threshold (E) to threshold (A)) H: total amount of toner supplemented (in threshold (E)) Total toner amount)
C: Maximum amount of toner that can be printed after shifting to toner near mode I: Number of dots of image data accumulated in toner usage amount storage means (counted from threshold (E) to threshold (A)) Number of exposure dots)
F: Correction coefficient D: Standard amount of toner used per dot

(Double-sided printing process in the second embodiment)
Hereinafter, the processing operation in the second embodiment will be described with reference to FIG.
First, when a command for executing double-sided printing is notified to the overall control unit (201), the overall control unit (201) causes the remaining toner amount detection unit (208) to execute a remaining toner amount detection process. Become. The overall control unit (201) determines whether the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than a predetermined threshold value (E) or the same value (M ≦ E). Is determined (step S101).

  When it is determined by the above determination that the remaining toner amount (M) is smaller than or equal to the predetermined threshold value (E) (step S101 / YES), the overall control unit (201) displays the image formation control unit (203). ) Starts counting the number of exposure dots when the double-sided printing process is executed (step S103). In this case, first, the image formation control unit (203) forms an image of the back surface image data stored in the image storage unit (209) on the first image carrier, and also stores it in the image storage unit (209). When the image of the stored front surface image data is formed on the first image carrier, the number of exposure dots of the back surface image data that the image formation control unit (203) writes on the first image carrier. And the overall control unit (201) is notified of the number of exposure dots of the counted back surface image data. The overall control unit (201) stores the notified number of exposure dots of the back surface image data in the toner usage amount storage means (207). Similarly, the image formation control unit (203) counts the number of exposure dots of the surface image data to be written on the first image carrier, and determines the number of exposure dots of the counted surface image data as the overall control unit (201). Notify The overall control unit (201) stores the number of exposure dots of the surface image data notified from the image formation control unit (203) in the toner usage amount storage unit (207).

  The overall control unit (201) causes the remaining toner amount detection unit (208) to execute the remaining toner amount detection process again, and the overall control unit (201) detects the toner detected by the remaining toner amount detection unit (208). It is determined whether the remaining amount (M) is smaller than or equal to a predetermined threshold value (A) (step S104).

  If the overall control unit (201) determines that the remaining toner amount (M) is larger than the predetermined threshold (A) (E> M> A) (step S104 / NO), the above determination results in the above. Similar to the process, the number of exposure dots is counted when the double-sided printing process is executed (steps S103 to S104). That is, the image formation control unit (203) counts the number of exposure dots of the image data to be written on the first image carrier, and notifies the overall control unit (201) of the counted number of exposure dots of the image data. The overall control unit (201) stores the number of exposure dots of the notified image data in the toner usage amount storage unit (207) and accumulates the number of exposure dots.

  Further, the overall control unit (201) determines that the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than or equal to a predetermined threshold value (A) (M ≦ A). In this case (step S104 / YES), the overall control unit (201) performs toner near-end mode duplex printing. At this time, the overall control unit (201) reads out the dot number (I) of the image data accumulated and stored in the toner usage amount storage means (207), and calculates the correction coefficient (F) by the following equation (4). (Step S105).

Formula (4)
G (g / dot) = (H (g) -C (g)) / I (dot)
F = G (g / dot) / D (g / dot)
G: amount of toner used per dot before transition to toner near mode (from threshold (E) to threshold (A)) H: total amount of toner supplemented (in threshold (E)) Total toner amount)
C: Maximum amount of toner that can be printed after shifting to toner near mode I: Number of dots of image data accumulated in toner usage amount storage means (counted from threshold (E) to threshold (A)) Number of dots)
F: Correction coefficient D: Standard amount of toner used per dot

  When the correction coefficient (F) is calculated by the above equation (4), the overall control unit (201) deletes the dot number (I) of the image data accumulated in the toner usage amount storage unit (207), and The operation control unit (206) is caused to execute a process of giving a toner near-end warning notifying the user of a state in which the remaining amount of toner is low (step S105).

  Next, the overall control unit (201) causes the reading control unit (202) to execute a document reading process (step S106), and the reading control unit (202) performs the document reading process, as described above. Further, the read image data for both sides read by the reading control unit (202) (the front surface image data printed on the front surface of the recording paper and the back surface image data printed on the back surface of the recording paper) are stored in the image storage unit (209). ) Will be stored. The overall control unit (201) causes the image formation control unit (203) to execute image formation processing in the toner near-end mode, and the image formation control unit (203) is stored in the image storage unit (209). Based on the image data (surface image data printed on the front side of the recording paper, back side image data printed on the back side of the recording paper), an image forming process of the image data is performed on the first image carrier. The image of the back image data stored in the image storage means (209) is formed on the first image carrier, and then the image of the front surface image data stored in the image storage means (209) is An image is formed on one image carrier. At this time, the number of exposure dots of the back surface image data to be formed on the first image carrier is counted, and the total number of exposure dots of the back surface image data is notified to the overall control unit (201). The image formation control unit (203) counts the number of exposure dots of the surface image data to be imaged on the first image carrier, and the total number of exposure dots of the surface image data thus counted is the overall control unit (201). (Step S107).

  The overall control unit (201) then determines the number of exposure dots (B) of the image data notified from the image formation control unit (203), the standard toner usage (D) per dot, and the above formula ( Using the correction coefficient (F) calculated from 4), the toner usage (N) used for the double-sided printing process is calculated by the following equation (5) (step S108).

Formula (5)
N (g) = B (g / dot) × D (dot) × F
N: amount of toner used B: number of exposure dots of image data D: standard amount of toner used per dot F: correction coefficient

  The overall control unit (201) stores the toner usage amount (N) calculated by the above equation (5) in the toner usage amount storage unit (207), and the toner usage amount storage unit (207) stores the toner usage amount. (N) is accumulated (step S109).

  Next, the overall control unit (201) reads the double-sided read image data (surface image data (P1) printed on the front surface of the recording paper, the back surface printed on the back surface of the recording paper). The image data (P2)) is taken out from the image storage means (209), and the toner usage amount (N ′) printed on the next recording paper is determined from the number of dots (P1, P2) of the read image data for both sides thus taken out. The prediction is made by the following equation (2) (step S110).

Formula (2)
N ′ (g) = D (g / dot) × (P1 (dot) + P2 (dot))
N ′: Estimated amount of toner used D: Standard amount of toner used per dot P1: Number of dots in front surface image data P2: Number of dots in back surface image data

  Next, the overall control unit (201) reads out the toner usage amount (U) accumulated in the toner usage amount storage means (207) and the maximum toner amount (C) that can be printed after shifting to the toner near mode. The current toner remaining amount (Z) is calculated by the following equation (3) (step S111).

Formula (3)
Z (g) = C (g) -U (g)
Z: current toner remaining amount C: maximum toner amount that can be printed after shifting to toner near mode U: toner usage amount accumulated in toner usage amount storage means

  Then, the overall control unit (201) compares the current toner remaining amount (Z) calculated by the above formula (3) with the estimated toner usage (N ′) used for the next double-sided printing process. Then, it is determined whether or not the next double-sided printing process is possible (step S112). In this determination, when the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is greater than the current toner remaining amount (Z) (N ′> Z). (Step S112 / YES), it is determined that the next double-sided printing process is impossible, and the overall control unit (201) causes the operation control unit (206) to execute a warning process without toner (Step S113). The double-sided printing process is terminated.

  When the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is less than or equal to the current toner remaining amount (Z) (Z ≧ N) ') (Step S112 / NO), it is determined that the next double-sided printing process is possible, and the overall control unit (201) causes the image forming control unit (203) to execute control of the double-sided printing process, The above process is repeated (steps S106 to S112).

  As described above, in the second embodiment, the number of exposure dots used when calculating the amount of toner used for double-sided printing is accumulated before the transition to the toner near mode, and the accumulated number of exposure dots is based on the accumulated number of exposure dots. In addition, by correcting the standard toner usage amount per dot that is applied when the toner usage amount calculated when the toner near mode is entered, the toner usage amount after the transition to the toner near mode is corrected. It is possible to calculate accurately.

Next, a third embodiment will be described.
In the third embodiment, before shifting to the toner near mode, the number of dots of the read image data for both sides read by the reading control unit (202) is stored in the toner usage amount storage means (207), and In Example 2, the standard toner usage amount per dot: D used in the above equation (2) for calculating the estimated toner usage amount (N ′) printed on the next recording paper is stored as the toner usage amount. Correction is performed based on the accumulated dot number of the read image data accumulated and stored in the means (207). As a result, the estimated toner usage calculated by the above equation (2) can be obtained more accurately. In order to carry out the present embodiment, in the second embodiment, the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than the second threshold (E). Alternatively, the read image data for both sides read by the reading control unit (202) from the time point when it is determined to be the same value (front surface image data printed on the front surface of the recording paper, back surface image data printed on the back surface of the recording paper) ) Is accumulated and stored in the toner usage amount storage means (207). Then, the reading control unit (202) reads until the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than or equal to the first threshold value (A). Based on the number of dots (K) of the read image data accumulated and stored in the toner usage amount storage means (207), the number of dots of the read image data for the both sides is stored in the toner usage amount storage means (207). The correction coefficient (J) is calculated by the following equation (6).

Formula (6)
G (g / dot) = (H (g) -C (g)) / K (dot)
J = G (g / dot) / D (g / dot)
G: Amount of toner used per dot of read image data before the transition to the toner near mode (from the threshold value (E) to the threshold value (A)) H: the total amount of toner compensated (the threshold value ( Total toner amount in E)
C: Maximum amount of toner that can be printed after shifting to toner near mode K: Number of dots of read image data accumulated in toner usage amount storage means (read control from threshold (E) to threshold (A)) The number of dots of scanned image data scanned by the scanner)
J: Correction coefficient D: Standard amount of toner used per dot

(Double-sided printing process in the third embodiment)
Next, processing operations in the third embodiment will be described with reference to FIG.
First, when a command for executing double-sided printing is notified to the overall control unit (201), the overall control unit (201) causes the remaining toner amount detection unit (208) to execute a remaining toner amount detection process. Become. The overall control unit (201) determines whether the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than a predetermined threshold value (E) or the same value (M ≦ E). Is determined (step S201).

  When it is determined by the above determination that the remaining toner amount (M) is smaller than or equal to the predetermined threshold value (E) (step S201 / YES), the overall control unit (201) reads the reading control unit (202). The number of dots of the read image data for both sides read by the above (surface image data printed on the front side of the recording paper, back side image data printed on the back side of the recording paper) is accumulated and stored in the toner usage amount storage means (207). (Step S203). The overall control unit (201) starts counting the number of exposure dots when the image forming control unit (203) executes the double-sided printing process (step S203).

  Then, the image formation control unit (203) counts the number of exposure dots of the image data to be written on the first image carrier, and notifies the overall control unit (201) of the number of exposure dots of the counted image data. become. Then, the overall control unit (201) cumulatively stores the number of exposure dots of the notified image data in the toner usage amount storage unit (207).

  Next, the overall control unit (201) causes the remaining toner amount detection unit (208) to execute a remaining toner amount detection process, and the overall control unit (201) detects the toner detected by the remaining toner amount detection unit (208). It is determined whether the remaining amount (M) is smaller than the predetermined threshold value (A) or the same value (M ≦ A) (step S204).

  If the overall control unit (201) determines that the remaining toner amount (M) is larger than the predetermined threshold value (A) (E> M> A) (step S204 / NO), the above determination is made. Similar to the processing, when the double-sided printing processing is executed, the number of dots of the read image data read by the reading control unit (202) is accumulated and stored in the toner usage amount storage means (207). The image forming control means (203) counts the number of exposure dots, and the counted number of exposure dots is accumulated and stored in the toner usage amount storage means (207) (steps S203 to S204).

  The overall control unit (201) determines that the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than or equal to a predetermined threshold value (A) (M ≦ A). In this case (step S204 / YES), the overall control unit (201) performs the double-sided printing process in the toner near-end mode. At this time, the overall control unit (201) reads the number of dots (K) of the read image data accumulated and stored in the toner usage amount storage means (207), and calculates the correction coefficient (J) by the following equation (6). This is calculated (step S205).

Formula (6)
G (g / dot) = (H (g) -C (g)) / K (dot)
J = G (g / dot) / D (g / dot)
G: Amount of toner used per dot of read image data before the transition to the toner near mode (from the threshold value (E) to the threshold value (A)) H: the total amount of toner compensated (the threshold value ( Total toner amount in E)
C: Maximum amount of toner that can be printed after shifting to toner near mode K: Number of dots of read image data accumulated in toner usage amount storage means (read control from threshold (E) to threshold (A)) The number of dots of scanned image data scanned by the scanner)
J: Correction coefficient D: Standard amount of toner used per dot

  The overall control unit (201) reads the exposure dot number (I) of the image data accumulated and stored in the toner usage amount storage unit (207), and calculates the correction coefficient (F) by the following equation (4). (Step S205).

Formula (4)
G (g / dot) = (H (g) -C (g)) / I (dot)
F = G (g / dot) / D (g / dot)
G: amount of toner used per dot before transition to toner near mode (from threshold (E) to threshold (A)) H: total amount of toner supplemented (in threshold (E)) Total toner amount)
C: Maximum amount of toner that can be printed after shifting to toner near mode I: Number of dots of image data accumulated in toner usage amount storage means (counted from threshold (E) to threshold (A)) Number of dots)
F: Correction coefficient D: Standard amount of toner used per dot

  When the correction coefficients (J, F) are calculated by the above formulas (6) and (4), the overall control unit (201) causes the dots of the read image data accumulated in the toner usage amount storage unit (207). The toner near-end warning is issued to delete the number (K) and the number of exposure dots (I) of the image data and notify the operation control unit (206) that the amount of remaining toner is low. The processing to be performed is executed (step S205).

  Next, the overall control unit (201) causes the reading control unit (202) to execute a document reading process (step S206), and the reading control unit (202) performs the document reading process, as described above. Further, the read image data for both sides read by the reading control unit (202) (the front surface image data printed on the front surface of the recording paper and the back surface image data printed on the back surface of the recording paper) are stored in the image storage unit (209). ) Will be stored. Next, the overall control unit (201) causes the image formation control unit (203) to execute image formation processing in the toner near-end mode, and the image formation control unit (203) is stored in the image storage unit (209). Based on the obtained image data (front image data printed on the front surface of the recording paper, back image data printed on the back surface of the recording paper), image data is processed on the first image carrier. Then, the number of exposure dots of the image data to be formed on the first image carrier is counted, and the total number of exposure dots of the image data is notified to the overall control unit (201) (step S207).

  The overall control unit (201) then determines the number of exposure dots (B) of the image data notified from the image formation control unit (203), the standard toner usage (D) per dot, and the above formula ( Using the correction coefficient (F) calculated from 4), the toner usage (N) used for the printing process is calculated by the following equation (5) (step S208).

Formula (5)
N (g) = B (g / dot) × D (dot) × F
N: amount of toner used B: number of exposure dots of image data D: standard amount of toner used per dot F: correction coefficient

  The overall control unit (201) stores the toner usage amount (N) calculated by the above equation (5) in the toner usage amount storage unit (207), and the toner usage amount storage unit (207) stores the toner usage amount. (N) is accumulated (step S209).

  Next, the overall control unit (201) reads the double-sided read image data (surface image data (P1) printed on the front surface of the recording paper, the back surface printed on the back surface of the recording paper). The image data (P2)) is taken out from the image storage means (209), the number of dots (P1, P2) of the read image data for both sides taken out, the correction coefficient (J) calculated from the above equation (6), Is used to predict the amount of toner used (N ′) printed on the next recording paper by the following equation (7) (step S210).

Formula (7)
N ′ (g) = D (g / dot) × (P1 (dot) + P2 (dot)) × J
N ′: Estimated amount of toner used D: Standard amount of toner used per dot P1: Number of dots in front surface image data P2: Number of dots in back surface image data J: Correction coefficient

  Next, the overall control unit (201) reads out the toner usage amount (U) accumulated in the toner usage amount storage means (207) and the maximum toner amount (C) that can be printed after shifting to the toner near mode. The current toner remaining amount (Z) is calculated by the following equation (3) (step S211).

Formula (3)
Z (g) = C (g) -U (g)
Z: current toner remaining amount C: maximum toner amount that can be printed after shifting to toner near mode U: toner usage amount accumulated in toner usage amount storage means

  Then, the overall control unit (201) compares the current toner remaining amount (Z) calculated by the above equation (3) with the estimated toner usage (N ′) used for the next double-sided printing process, It is determined whether or not the next double-sided printing process is possible (step S212). In this determination, when the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is greater than the current toner remaining amount (Z) (N ′> Z). (Step S212 / YES), it is determined that the next double-sided printing process is impossible, and the overall control unit (201) causes the operation control unit (206) to execute a warning process without toner (step S213). The double-sided printing process is terminated.

  When the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is less than or equal to the current toner remaining amount (Z) (Z ≧ N) ') (Step S212 / NO), it is determined that the next double-sided printing process is possible, and the overall control unit (201) causes the image forming control unit (203) to control the double-sided printing process, The above process is repeated (steps S206 to S212).

  As described above, in the third embodiment, the number of dots of the read image data used when calculating the estimated amount of toner used for double-sided printing is integrated before the transition to the toner near mode, and the integrated reading is performed. Shifts to toner near mode by correcting the standard toner usage per dot applied when obtaining the estimated toner usage calculated when shifting to toner near mode based on the number of dots in the image data It is possible to accurately calculate the estimated toner usage after this.

Next, a fourth embodiment will be described.
The first to third embodiments correspond to toner supply means such as a powder pump (not shown) from a cartridge (TC) disposed in the toner storage portion (TS) of the image forming apparatus shown in FIG. The double-sided printing process in the configuration in which the toner-color developing device (5) is appropriately replenished has been described. However, as shown in FIG. Also, it is possible to perform the double-sided printing process similar to the first to third embodiments. As shown in FIG. 8, a process cartridge (PC) including a photosensitive drum as a first image carrier, a cleaning device, a charge eliminating device, a charging device, a developing device, and a toner cartridge. Is unitized by a cover which is a frame covering all devices. Further, as shown in FIG. 9, the functional configuration of the image forming apparatus having a detachable process cartridge (PC) includes a toner usage amount storage means (207) and a toner remaining amount detection means (on the process cartridge (PC)). 208).

  As shown in FIG. 1, the double-sided printing process according to the present invention is appropriately supplied from the cartridge (TC) to the corresponding toner color developing device (5) by a toner supply means such as a powder pump (not shown). By making the configuration of the image forming apparatus include the process cartridge shown in FIG. 8, it is possible to further simplify the double-sided printing process in the second and third embodiments. Hereinafter, with reference to FIGS. 10 and 11, the duplex printing process in which the second and third embodiments are simplified will be described.

(Simplified duplex printing process of the second embodiment)
First, referring to FIG. 10, a duplex printing process in which the second embodiment is simplified will be described.

  In the second embodiment, the corresponding toner color developing device (5) is appropriately supplied from a cartridge (TC) disposed in the toner storage portion (TS) by a toner supply means such as a powder pump (not shown). The second threshold value (E) larger than a predetermined threshold value (A) for determining whether or not to shift to the toner near mode is set (A <E), and the toner remaining amount detecting means From the time when it is determined that the remaining toner amount (M) detected by (208) is smaller than or equal to the second threshold value (E), the image forming control unit (203) counts the number of exposure dots, The counted number of exposure dots is stored in the toner usage amount storage means (207), and the toner remaining amount (M) detected by the toner remaining amount detection means (208) is smaller than the first threshold value (A), or Until the time when the same value is judged (203) stores the number of exposure dots counted toner density storing means (207). Then, the correction coefficient (F) is calculated based on the number of exposure dots accumulated and stored in the toner usage amount storage means (207). Since the toner amount can be grasped in advance, it is not necessary to set the second threshold value (E).

  First, when a command for executing double-sided printing is notified to the overall control unit (201), the overall control unit (201) causes the remaining toner amount detection unit (208) to execute a remaining toner amount detection process. Become. Then, the overall control unit (201) determines whether or not the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than a predetermined threshold (A) or the same value (M ≦ A). Is determined (step S301).

  When it is determined by the above determination that the remaining toner amount (M) is larger than the predetermined threshold (A) (M> A) (step S301 / NO), the overall control unit (201) 202) is executed to read the original (step S302). At this time, the image forming control unit (203) is caused to count the number of exposure dots when the double-sided printing process is executed, and the image forming control unit (203) stores the image data stored in the image storage unit (209). When the image is formed on the first image carrier, the image formation control unit (203) counts the number of exposure dots of the image data to be written on the first image carrier, and the counted image data Is notified to the overall control unit (201). The overall control unit (201) stores the notified number of exposure dots of the image data in the toner usage amount storage unit (207).

  Then, the overall control unit (201) causes the remaining toner amount detection means (208) to execute the remaining toner amount detection process again, and the remaining toner amount (M) detected by the remaining toner amount detection means (208) is a predetermined value. The above processing operation is repeated until it is determined that the value is smaller than or equal to the threshold value (A), and the number of exposure dots of the image data to be written on the first image carrier is counted. The number of exposure dots is accumulated and stored in the toner usage amount storage means (207) (steps S301 to S302).

  The overall control unit (201) determines that the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than or equal to a predetermined threshold value (A) (M ≦ A). In this case (step S301 / YES), the overall control unit (201) performs the toner near-end mode duplex printing process (step S303). At this time, the overall control unit (201) reads the dot number (I) of the image data accumulated and stored in the toner usage amount storage means (207), and calculates the correction coefficient (F) by the following equation (4). (Step S303).

Formula (4)
G (g / dot) = (H (g) -C (g)) / I (dot)
F = G (g / dot) / D (g / dot)
G: amount of toner used per dot before shifting to toner near mode H: total amount of toner supplemented (total amount of toner in process cartridge)
C: Maximum amount of toner that can be printed after shifting to toner near mode I: Number of exposure dots of image data accumulated in toner usage amount storage means (number of exposure dots counted before shifting to toner near mode)
F: Correction coefficient D: Standard amount of toner used per dot

  When the correction coefficient (F) is calculated by the above equation (4), the overall control unit (201) erases the number of exposure dots (I) of the image data accumulated in the toner usage amount storage unit (207). Then, the operation control unit (206) is caused to execute a process of giving a toner near-end warning notifying the user of a state where the remaining amount of toner is low (step S303).

  Next, the overall control unit (201) causes the reading control unit (202) to execute a document reading process (step S304) and, as described above, for both sides read by the reading control unit (202). The read image data (surface image data printed on the front surface of the recording paper, back surface image data printed on the back surface of the recording paper) is stored in the image storage means (209). Next, the overall control unit (201) causes the image formation control unit (203) to execute image formation processing in the toner near-end mode, and the image formation control unit (203) is stored in the image storage unit (209). Based on the obtained image data (front image data printed on the front surface of the recording paper, back image data printed on the back surface of the recording paper), image data is processed on the first image carrier. The image of the image data stored in the image storage means (209) is imaged on the first image carrier, and the number of exposure dots of the image data to be imaged on the first image carrier is counted. The number of exposure dots of the counted image data is notified to the overall control unit (201) (step S305).

  The overall control unit (201) calculates the number of exposure dots (B) of the image data notified from the image formation control unit (203), the standard toner usage (D) per dot, and the above calculation. Using the correction coefficient (F), the toner usage (N) used for the double-sided printing process is calculated by the following equation (5) (step S306).

Formula (5)
N (g) = B (g / dot) × D (dot) × F
N: amount of toner used B: number of exposure dots of image data D: standard amount of toner used per dot F: correction coefficient

  The overall control unit (201) stores the toner usage amount (N) calculated by the above equation (5) in the toner usage amount storage unit (207), and the toner usage amount storage unit (207) stores the toner usage amount. (N) is accumulated (step S307).

  Next, the overall control unit (201) reads the double-sided read image data (surface image data (P1) printed on the front surface of the recording paper, the back surface printed on the back surface of the recording paper). The image data (P2)) is taken out from the image storage means (209), and the toner usage amount (N ′) printed on the next recording paper is determined from the number of dots (P1, P2) of the read image data for both sides thus taken out. The prediction is made by the following equation (2) (step S308).

Formula (2)
N ′ (g) = D (g / dot) × (P1 (dot) + P2 (dot))
N ′: Estimated amount of toner used D: Standard amount of toner used per dot P1: Number of dots in front surface image data P2: Number of dots in back surface image data

  Next, the overall control unit (201) reads out the toner usage amount (U) accumulated in the toner usage amount storage means (207) and the maximum toner amount (C) that can be printed after shifting to the toner near mode. The current toner remaining amount (Z) is calculated by the following equation (3) (step S309).

Formula (3)
Z (g) = C (g) -U (g)
Z: current toner remaining amount C: maximum toner amount that can be printed after shifting to toner near mode U: toner usage amount accumulated in toner usage amount storage means

  Then, the overall control unit (201) compares the current toner remaining amount (Z) calculated by the above equation (3) with the estimated toner usage (N ′) used for the next double-sided printing process, It is determined whether or not the next double-sided printing process is possible (step S310). In this determination, when the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is greater than the current toner remaining amount (Z) (N ′> Z). (Step S310 / YES), it is determined that the next double-sided printing process is impossible, and the overall control unit (201) causes the operation control unit (206) to execute a warning process without toner (step S311). The double-sided printing process is terminated.

  When the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is less than or equal to the current toner remaining amount (Z) (Z ≧ N) ') (Step S310 / NO), it is determined that the next double-sided printing process is possible, and the overall control unit (201) causes the image forming control unit (203) to execute control of the double-sided printing process, The above process is repeated (steps S304 to S310).

  As described above, in this embodiment, as in the second embodiment, the number of exposure dots used when calculating the amount of toner used for double-sided printing is integrated before the transition to the toner near mode, and the integration is performed. Based on the number of exposed dots, the toner toner mode was entered by correcting the standard toner usage per dot applied when determining the toner usage calculated when the toner near mode was entered. It becomes possible to accurately calculate the amount of toner used later.

(Simplified duplex printing process of the third embodiment)
Next, with reference to FIG. 11, a duplex printing process in which the third embodiment is simplified will be described. In the present embodiment, similarly to the duplex printing process simplified in the second embodiment, the duplex printing process is performed without setting the second threshold (E).

  First, when a command for executing double-sided printing is notified to the overall control unit (201), the overall control unit (201) causes the remaining toner amount detection unit (208) to execute a remaining toner amount detection process. Become. Then, the overall control unit (201) determines whether or not the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than a predetermined threshold (A) or the same value (M ≦ A). Is determined (step S401).

  When it is determined by the above determination that the remaining toner amount (M) is larger than the predetermined threshold (A) (M> A) (step S401 / NO), the overall control unit (201) displays the reading control unit (202). ) Is accumulated in the toner usage amount storage means (207) for both sides of the read image data (surface image data printed on the front side of the recording paper and back side image data printed on the back side of the recording paper). This is stored (step S402). The overall control unit (201) causes the image formation control unit (203) to count the number of exposure dots when the double-sided printing process is executed, and the image formation control unit (203) performs image storage means (209). When the image data image stored in (1) is formed on the first image carrier, the image formation control unit (203) counts the number of exposure dots of the image data to be written on the first image carrier. The number of exposure dots of the counted image data is notified to the overall control unit (201). Then, the overall control unit (201) accumulates and stores the number of exposure dots of the notified image data in the toner usage amount storage unit (207) (step S402).

  Then, the overall control unit (201) causes the remaining toner amount detection means (208) to execute the remaining toner amount detection process again, and the remaining toner amount (M) detected by the remaining toner amount detection means (208) is a predetermined value. The above processing operation is repeated until it is determined that the value is smaller than the threshold value (A) or the same value (M ≦ A), and read image data for both sides read by the reading control unit (202) (recording paper The number of dots of the front surface image data printed on the front surface and the back surface image data printed on the back surface of the recording paper is accumulated and stored in the toner usage amount storage means (207). Further, the image forming control unit (203) counts the number of exposure dots of the image data to be written on the first image carrier, and cumulatively stores the number of exposure dots of the counted image data in the toner usage amount storage means (207). (Steps S401 to S402).

  The overall control unit (201) determines that the toner remaining amount (M) detected by the toner remaining amount detecting means (208) is smaller than or equal to a predetermined threshold value (A) (M ≦ A). In this case (step S401 / YES), the overall control unit (201) performs the toner near-end mode duplex printing process (step S403). At this time, the overall control unit (201) reads the number of dots (K) of the read image data accumulated and stored in the toner usage amount storage means (207), and calculates the correction coefficient (J) by the following equation (6). (Step S403).

Formula (6)
G (g / dot) = (H (g) -C (g)) / K (dot)
J = G (g / dot) / D (g / dot)
G: Amount of toner used per dot of read image data before shifting to the toner near mode H: Total amount of toner supplemented (total amount of toner in the process cartridge)
C: Maximum amount of toner that can be printed after shifting to toner near mode K: Number of dots of read image data accumulated in toner usage amount storage means J: Correction coefficient D: Standard amount of toner usage per dot

  The overall control unit (201) reads the exposure dot number (I) of the image data accumulated and stored in the toner usage amount storage unit (207), and calculates the correction coefficient (F) by the following equation (4). (Step S403).

Formula (4)
G (g / dot) = (H (g) -C (g)) / I (dot)
F = G (g / dot) / D (g / dot)
G: Amount of toner used per dot of read image data before shifting to the toner near mode H: Total amount of toner supplemented (total amount of toner in the process cartridge)
C: Maximum toner amount that can be printed after shifting to toner near mode I: Number of exposure dots of image data accumulated in toner usage amount storage means F: Correction coefficient D: Standard toner usage amount per dot

  When the correction coefficients (J, F) are calculated by the above formulas (6) and (4), the overall control unit (201) causes the dots of the read image data accumulated in the toner usage amount storage unit (207). The toner near-end warning is issued to delete the number (K) and the number of exposure dots (I) of the image data and notify the operation control unit (206) that the amount of remaining toner is low. The process to be performed is executed (step S403).

  Next, the overall control unit (201) causes the reading control unit (202) to execute a document reading process (step S404), and the reading control unit (202) performs the document reading process, as described above. Further, the read image data for both sides read by the reading control unit (202) (the front surface image data printed on the front surface of the recording paper and the back surface image data printed on the back surface of the recording paper) are stored in the image storage unit (209). ) Will be stored. The overall control unit (201) causes the image formation control unit (203) to execute image formation processing in the toner near-end mode, and the image formation control unit (203) is stored in the image storage unit (209). Based on the image data (surface image data printed on the front surface of the recording paper, back image data printed on the back surface of the recording paper), image data is imaged on the first image carrier, The number of exposure dots of the image data to be imaged on the first image carrier is counted, and the total number of exposure dots of the image data is notified to the overall control unit (201) (step S405).

  The overall control unit (201) then determines the number of exposure dots (B) of the image data notified from the image formation control unit (203), the standard toner usage (D) per dot, and the above formula ( Using the correction coefficient (F) calculated from 4), the toner usage amount (N) used for the printing process is calculated by the following equation (5) (step S406).

Formula (5)
N (g) = B (g / dot) × D (dot) × F
N: amount of toner used B: number of exposure dots of image data D: standard amount of toner used per dot F: correction coefficient

  The overall control unit (201) stores the toner usage amount (N) calculated by the above equation (5) in the toner usage amount storage unit (207), and the toner usage amount storage unit (207) stores the toner usage amount. (N) is accumulated (step S407).

  Next, the overall control unit (201) reads the double-sided read image data (surface image data (P1) printed on the front surface of the recording paper, the back surface printed on the back surface of the recording paper). The image data (P2)) is taken out from the image storage means (209), the number of dots (P1, P2) of the read image data for both sides taken out, the correction coefficient (J) calculated from the above equation (6), Is used to predict the amount of toner used (N ′) printed on the next recording paper by the following equation (7) (step S408).

Formula (7)
N ′ (g) = D (g / dot) × (P1 (dot) + P2 (dot)) × J
N ′: Estimated amount of toner used D: Standard amount of toner used per dot P1: Number of dots in front surface image data P2: Number of dots in back surface image data J: Correction coefficient

  Next, the overall control unit (201) reads out the toner usage amount (U) accumulated in the toner usage amount storage means (207) and the maximum toner amount (C) that can be printed after shifting to the toner near mode. The current toner remaining amount (Z) is calculated by the following equation (3) (step S409).

Formula (3)
Z (g) = C (g) -U (g)
Z: current toner remaining amount C: maximum toner amount that can be printed after shifting to toner near mode U: toner usage amount accumulated in toner usage amount storage means

  Then, the overall control unit (201) compares the current toner remaining amount (Z) calculated by the above equation (3) with the estimated toner usage (N ′) used for the next double-sided printing process, It is determined whether or not the next double-sided printing process is possible (step S410). In this determination, when the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is greater than the current toner remaining amount (Z) (N ′> Z). (Step S410 / YES), it is determined that the next double-sided printing process is impossible, and the overall control unit (201) causes the operation control unit (206) to execute a warning process without toner (step S411). The double-sided printing process is terminated.

  When the overall control unit (201) determines that the estimated toner usage (N ′) used for the next double-sided printing process is less than or equal to the current toner remaining amount (Z) (Z ≧ N) ') (Step S410 / NO), it is determined that the next double-sided printing process is possible, and the overall control unit (201) causes the image forming control unit (203) to control the double-sided printing process, The above process is repeated (steps S404 to S410).

  As described above, in this embodiment, as in the third embodiment, the number of dots of the read image data used when calculating the estimated amount of toner used for double-sided printing is integrated from before the transition to the toner near mode. Then, by correcting the standard toner usage amount per dot applied when obtaining the estimated toner usage amount calculated when the mode is shifted to the toner near mode based on the accumulated number of dots of the read image data. Thus, it is possible to accurately calculate the estimated toner usage after the transition to the toner near mode.

  Note that the image forming apparatus shown in FIG. 8 includes a process cartridge (PC) that is detachable from the main body of the image forming apparatus. The process cartridge (PC) includes a charging device, a developing device, and a cleaning device. A process cartridge configured integrally with a device and a photosensitive drum, or at least one device of a charging device, a developing device, and a cleaning device, and a photosensitive drum integrated It is possible to apply a process cartridge that has been formed, or a process cartridge that is configured by integrating at least a developing device and a photosensitive drum. Further, a contact type IC chip, a non-contact type IC chip, or a non-contact type IC card can be applied to the toner usage amount storage means (207).

Next, a fifth embodiment will be described.
In the first to fourth embodiments, the processing operation when performing the double-sided printing process in the image forming apparatus alone has been described. However, as shown in FIG. 12, the image forming apparatuses in the first to fourth embodiments described above. (1000) and a personal computer (2000) are connected, and information on the remaining amount of toner as shown in FIGS. 4 and 5 can be notified to the host computer (2000) via an interface. . In this case, first, information for executing double-sided printing processing in the image forming apparatus (1000) is transmitted from the host computer (2000) side, and the first to fourth implementations are performed on the image forming apparatus (1000) side. The double-sided printing process in the example is performed, and the information displayed on the display unit or the like of the image forming apparatus in the first to fourth embodiments is notified to the host computer (2000) connected via the interface, and the host It is displayed on the display unit on the computer (2000) side. As described above, the host computer side via the interface indicates that the remaining amount of toner is low as shown in FIG. 4 (toner near-end warning), and that double-sided printing processing cannot be executed as shown in FIG. (Warning) can also be notified.

  The above-described embodiments are preferred embodiments of the present invention, and various modifications can be made without departing from the scope of the present invention. For example, in the above embodiment, the color image forming process using a plurality of color toners has been described. However, the present invention can also be applied to a monochrome image forming process. In addition to the embodiments described above, the processing operation described above is also applied to a case (double-sided printing, divided printing, etc. of a single-sided document) that holds a plurality of visible images on the third image carrier (100). Is possible. Further, the third image carrier (100) has been described as a case that holds a visible image for two pages. However, the above-described processing operation can be applied even when a third image is held. is there. In the above embodiment, the number of printable sheets (L) from the remaining toner remaining amount (Z) based on the remaining toner amount (Z) calculated by the equation (3) is expressed by the following equation (8). It is also possible to calculate and notify the user.

Formula (8)
L = Z / L '
L: Number of printable sheets from remaining toner level Z: Current toner level L ': Standard amount of toner used per sheet

  In the above-described embodiment, whether or not double-sided printing processing is possible is determined based on the amount of toner used. However, whether or not double-sided printing processing is possible is similar to that in the above-described embodiment even if this toner amount is replaced with a printing area. It is possible to do. This is because the printing area can be calculated based on the toner amount (printing area (S) = proportional constant (α) × toner amount (Β)).

  The image forming apparatus, the process cartridge, and the double-sided printing control method according to the present invention can be applied to an image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the present invention. FIG. 3 is a diagram showing a control block when controlling the image forming apparatus according to the present invention. It is a flowchart which shows the double-sided printing process in a 1st Example. FIG. 6 is an image diagram when a message indicating that the remaining amount of toner is decreasing is displayed on a display unit included in the image forming apparatus. FIG. 6 is an image diagram when a message indicating that double-sided printing cannot be performed is displayed on a display unit included in the image forming apparatus. It is a flowchart which shows the double-sided printing process in a 2nd Example. It is a flowchart which shows the double-sided printing process in a 3rd Example. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the present invention, and is a diagram illustrating a configuration including a process cartridge that is detachable from a main body of the image forming apparatus. FIG. 3 is a diagram illustrating a control block when controlling the image forming apparatus according to the present invention, and is a diagram illustrating a configuration including a process cartridge. It is a flowchart which shows the processing operation which simplified the double-sided printing process in 2nd Example. It is a flowchart which shows the processing operation which simplified the double-sided printing process in the 3rd Example. 1 is a diagram illustrating a configuration example in which an image forming apparatus according to the present invention is connected to an external host computer via a network.

Explanation of symbols

A Paper discharge direction L Static neutralizer P Recording medium (paper)
CH Charger TS Toner storage TC Toner cartridge 1 First image carrier (photosensitive drum)
2 Cleaning device for first image carrier (photoconductor) 3 Charging device 4 Exposure device 5 Developing device 10 Second image carrier (intermediate transfer belt)
11, 12, 13 Rotating roller (support shaft of second image carrier)
20 First transfer means 25 Second image carrier (intermediate transfer belt) cleaning device 26-1, 26-2 Paper feed device (paper feed cassette)
27 Paper Feed Roller 28 Registration Roller Pair 29 Conveyance Guide 30 Fixing Heating Means 31 Paper Discharge Guide Pair 32 Paper Discharge Roller Pair 40 Paper Discharge Stack Unit 50 Opening / Closing Frame 50A Opening / Closing Support Shaft 100 Third Image Carrier (Intermediate Transfer Belt)
111, 112, 113 Rotating roller (support shaft of third image carrier)
120 second transfer means,
250 Third image carrier cleaning device 250A Cleaning swing fulcrum 250B Toner storage unit 201 Overall control unit 202 Reading control unit 203 Image formation control unit 204 Paper conveyance control unit 205 Fixing control unit 206 Operation control unit 207 Toner usage amount storage Means 208 Toner remaining amount detection means 209 Image storage means PC process cartridge 1000 Image forming apparatus 2000 Host computer

Claims (34)

A first image carrier, a second image carrier, a third image carrier, and an image forming means for forming a visible image on the first image carrier; The first visible image formed on the first image carrier is transferred from the first image carrier to the second image carrier, and the third image carrier is further transferred from the second image carrier. The first visible image transferred onto the third image carrier and transferred onto the third image carrier is transferred to one surface of the recording medium, and the first image formed on the first image carrier by the imaging means. The second visible image is transferred from the first image carrier to the second image carrier, and the second visible image transferred onto the second image carrier is transferred to the other surface of the recording medium. An image forming apparatus for transferring a visible image on both sides of the recording medium,
A developing remaining amount detecting means for detecting the remaining amount of developer supplied to the image forming means;
A double-sided transfer execution determination unit that determines whether or not the remaining amount detected by the development remaining amount detection unit secures an amount for transferring a visible image on both sides of the recording medium;
Double-sided transfer that transfers a visible image on both sides of the recording medium only when the remaining-side transfer execution determining means determines that the remaining amount is sufficient to transfer the visible image on both sides of the recording medium Execution means;
An image forming apparatus comprising:   When the double-sided transfer execution determining unit determines that the remaining amount does not secure an amount for transferring a visible image on both sides of the recording medium, a message indicating that double-sided printing on the recording medium cannot be performed is displayed. The image forming apparatus according to claim 1, further comprising a display unit configured to display the display unit.   If it is determined by the double-sided transfer execution determining means that the remaining amount does not secure an amount for transferring a visible image on both sides of the recording medium, it is indicated that double-sided printing on the recording medium cannot be executed externally. The image forming apparatus according to claim 1, further comprising a notification unit configured to notify the communication apparatus.   2. The image forming apparatus according to claim 1, wherein the first image carrier, the image forming unit, and the development remaining amount detecting unit are provided at least in a process cartridge that is detachable from the image forming apparatus main body. apparatus. The development remaining amount detecting means includes
Means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less;
Usage amount storage means for converting the usage amount of the developer used when the visible image is formed by the imaging means from the time when the remaining amount becomes a predetermined value or less, and accumulating the converted usage amount. And having
2. The residual amount of developer is detected by subtracting the usage amount accumulated in the usage amount storage means from the residual amount of developer at the time when the predetermined value or less is reached. Or the image forming apparatus of 4. Means for detecting that the remaining amount of developer supplied to the image forming means has become a second predetermined value or less;
The amount of developer used when the visible image is formed by the image forming means from the time when the remaining amount becomes equal to or less than the second predetermined value to the time when the remaining amount becomes equal to or less than the predetermined value. And based on the usage amount of the developer accumulated and stored until the remaining amount becomes equal to or less than the predetermined value, the used amount storage means from the time when the remaining amount becomes equal to or less than the predetermined value. Correction coefficient calculation means for calculating a correction coefficient when converting the amount of use of the developer accumulated and stored,
The usage amount storage means includes:
Using the correction coefficient calculated by the correction coefficient calculation means, the usage amount of the developer used when the visible image is formed by the image forming means from the time when the predetermined value or less is corrected, 6. The image forming apparatus according to claim 5, wherein the corrected usage amount of the developer is accumulated and stored. The used amount of developer used when the visible image is formed by the image forming means until the remaining amount becomes the predetermined value or less is accumulated and stored, and the remaining amount becomes the predetermined value or less. When converting the usage amount of the developer accumulated and stored in the usage amount storage means from the time when the remaining amount becomes the predetermined value or less based on the usage amount of the developer accumulated and stored up to Correction coefficient calculating means for calculating the correction coefficient of
The usage amount storage means includes:
Using the correction coefficient calculated by the correction coefficient calculation means, the usage amount of the developer used when the visible image is formed by the image forming means from the time when the predetermined value or less is corrected, 6. The image forming apparatus according to claim 5, wherein the corrected usage amount of the developer is accumulated and stored.   8. The display device according to claim 5, further comprising a display unit that displays that the remaining amount of the developer has decreased when it is detected that the remaining amount of the developer has become a predetermined value or less. The image forming apparatus according to claim 1.   The apparatus further comprises notification means for notifying an external communication device that the remaining amount of the developer has decreased when it is detected that the remaining amount of the developer has become a predetermined value or less. The image forming apparatus according to any one of 5 to 8. The double-sided transfer execution determination means
A developer usage amount predicting means for predicting a usage amount of the developer used when forming a visible image of both sides transferred to the recording medium on the first image carrier,
By determining whether or not the remaining amount detected by the remaining developing amount detection unit is equal to or greater than the usage amount of the developer predicted by the developer usage amount predicting unit, the remaining amount appears on both sides of the recording medium. Determine if you have enough to transfer the image,
When it is determined that the remaining amount detected by the developer remaining amount detecting unit is equal to or larger than the developer usage amount predicted by the developer usage amount predicting unit, the remaining amount is visualized on both sides of the recording medium. The image forming apparatus according to claim 1, wherein it is determined that an amount for transferring the image is secured. Means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less;
Means for detecting that the remaining amount of developer supplied to the image forming means has become a second predetermined value or less;
On both sides of the first image carrier, visible images of both sides transferred to the recording medium from when the remaining amount becomes equal to or less than a second predetermined value to when the remaining amount becomes equal to or less than the predetermined value. The amount of developer used when formed on the first image carrier is accumulated and stored on the first image carrier based on the accumulated amount of developer used. Correction coefficient calculation means for calculating a correction coefficient for predicting the usage amount of the developer used when formed into
The developer usage amount predicting means is:
When a visible image for both sides to be transferred to the recording medium is formed on the first image carrier using the correction coefficient calculated by the correction coefficient calculation means from the time when the predetermined value or less is reached. The image forming apparatus according to claim 10, wherein the usage amount of the developer to be used is corrected and prediction is performed based on the corrected usage amount. Means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less;
Cumulatively storing the amount of developer used when a visible image of both sides to be transferred to the recording medium is formed on the first image carrier by the time when the remaining amount becomes the predetermined value or less; Based on the accumulated usage amount of the developer, the usage amount of the developer used when the visible images for both surfaces transferred to the recording medium are formed on the first image carrier is predicted. Correction coefficient calculation means for calculating a correction coefficient when performing,
The developer usage amount predicting means is:
When a visible image for both sides to be transferred to the recording medium is formed on the first image carrier using the correction coefficient calculated by the correction coefficient calculation means from the time when the predetermined value or less is reached. The image forming apparatus according to claim 10, wherein the usage amount of the developer to be used is corrected and prediction is performed based on the corrected usage amount.   The image forming apparatus according to claim 5, wherein the usage amount storage unit is a contact type IC chip.   The image forming apparatus according to claim 5, wherein the usage amount storage unit is a non-contact type IC chip.   The image forming apparatus according to claim 5, wherein the usage amount storage unit is a contact type IC card.   The image forming apparatus according to claim 5, wherein the usage amount storage unit is a nonvolatile memory. An image carrier that holds a visible image, an image forming unit that forms a visible image on the image carrier, and a development remaining amount detection unit that detects a remaining amount of developer supplied to the image forming unit. A process cartridge detachable from the main body of the image forming apparatus,
The development remaining amount detecting means includes
Means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less;
Usage amount storage means for converting the usage amount of the developer used when the visible image is formed by the imaging means from the time when the remaining amount becomes a predetermined value or less, and accumulating the converted usage amount. And having
A process cartridge for detecting the remaining amount of developer by subtracting the used amount accumulated in the used amount storage means from the remaining amount of developer at the time when the predetermined value or less is reached. Means for detecting that the remaining amount of developer supplied to the image forming means has become a second predetermined value or less;
The amount of developer used when the visible image is formed by the image forming means from the time when the remaining amount becomes equal to or less than the second predetermined value to the time when the remaining amount becomes equal to or less than the predetermined value. And the usage amount storage from the time when the remaining amount becomes less than the predetermined value based on the accumulated usage amount of the developer accumulated until the time when the remaining amount becomes less than the predetermined value. Correction coefficient calculation means for calculating a correction coefficient for converting the amount of the developer accumulated and stored in the means,
The usage amount storage means includes:
Using the correction coefficient calculated by the correction coefficient calculation means, the usage amount of the developer used when the visible image is formed by the image forming means from the time when the predetermined value or less is corrected, 18. The process cartridge according to claim 17, wherein the corrected usage amount of the developer is accumulated and stored. The used amount of developer used when the visible image is formed by the image forming means until the remaining amount becomes the predetermined value or less is accumulated and stored, and the remaining amount becomes the predetermined value or less. When converting the usage amount of the developer accumulated and stored in the usage amount storage means from the time when the remaining amount becomes the predetermined value or less based on the usage amount of the developer accumulated and stored up to Correction coefficient calculating means for calculating the correction coefficient of
The usage amount storage means includes:
Using the correction coefficient calculated by the correction coefficient calculation means, the usage amount of the developer used when the visible image is formed by the image forming means from the time when the predetermined value or less is corrected, 18. The process cartridge according to claim 17, wherein the corrected usage amount of the developer is accumulated and stored.   20. The process cartridge according to claim 17, wherein the usage amount storage means is a contact type IC chip.   20. The process cartridge according to claim 17, wherein the usage amount storage means is a non-contact type IC chip.   The process cartridge according to any one of claims 17 to 19, wherein the usage amount storage means is a contact type IC card.   The process cartridge according to claim 17, wherein the usage amount storage unit is a nonvolatile memory. A first image carrier, a second image carrier, a third image carrier, an image forming means for forming a visible image on the first image carrier, and the first image carrier by the first image carrier; The first visible image formed on the image carrier is transferred from the first image carrier to the second image carrier, and further transferred from the second image carrier to the third image carrier. The first visible image transferred onto the third image carrier is transferred to one surface of the recording medium, and the second visible image formed on the first image carrier by the imaging means. Is transferred from the first image carrier to the second image carrier, the second visible image transferred onto the second image carrier is transferred to the other surface of the recording medium, and the recording In an image forming apparatus, comprising: a transfer unit that transfers a visible image on both sides of a medium; a remaining developing amount detection unit that detects a remaining amount of developer supplied to the image forming unit; and a control unit A surface printing control method,
The control means is
A double-sided transfer execution determination step for determining whether or not the remaining amount detected by the remaining developing amount detection means secures an amount for transferring a visible image on both sides of the recording medium;
Only when it is determined in the double-sided transfer execution determination step that the remaining amount secures an amount for transferring the visible image on both sides of the recording medium, the transfer means applies the visible image on both sides of the recording medium. A double-sided transfer execution process to transfer,
Performing a double-sided printing control method. The image forming apparatus further includes a display unit,
The control means is
When it is determined by the double-sided transfer execution determination step that the remaining amount does not secure an amount for transferring a visible image on both sides of the recording medium, it is indicated that double-sided printing on the recording medium cannot be executed. The double-sided printing control method according to claim 24, further comprising a display step of displaying on the display unit. The image forming apparatus further includes communication means for transmitting / receiving information to / from an external communication device,
The control means is
When it is determined by the double-sided transfer execution determination step that the remaining amount does not secure an amount for transferring a visible image on both sides of the recording medium, it is indicated that double-sided printing on the recording medium cannot be executed. 26. The double-sided printing control method according to claim 24, further comprising a notifying step of notifying the external communication device by communication means. The development remaining amount detecting means includes
Means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less;
A usage amount storage means for storing the remaining amount of the developer at the time when the predetermined value or less is reached, and the usage amount of the developer, and
The development remaining amount detecting means includes
When it is detected that the remaining amount is equal to or less than a predetermined value, the usage amount of the developer used when the visible image is formed by the imaging means is converted, and the converted usage amount is A usage storage step for accumulating and storing the usage storage means;
The remaining amount of developer is subtracted from the remaining amount of developer stored in the used amount storage means from the remaining amount of developer when the amount is less than or equal to the predetermined value. A detection step for detecting
25. The double-sided printing control method according to claim 24, wherein: The development remaining amount detecting means includes
Means for detecting that the remaining amount of developer supplied to the image forming means has become a second predetermined value or less;
The amount of developer used when the visible image is formed by the image forming means from the time when the remaining amount becomes equal to or less than the second predetermined value to the time when the remaining amount becomes equal to or less than the predetermined value. Is stored in the usage amount storage unit, and the remaining amount is determined based on the usage amount of the developer accumulated and stored in the usage amount storage unit until the remaining amount becomes equal to or less than the predetermined value. Correction coefficient calculation means for calculating a correction coefficient when converting the usage amount of the developer accumulated and stored in the usage amount storage means from the time when the value becomes equal to or less than a value;
The development remaining amount detecting means includes
Use of the developer used when the visible image is formed by the image forming means using the correction coefficient calculated by the correction coefficient calculating means when it is detected that the value is equal to or less than the predetermined value. 28. The double-sided printing control method according to claim 27, wherein the amount is corrected, and the corrected usage amount of the developer is accumulated and stored in the usage amount storage means. The usage amount of the developer used when the visible image is formed by the imaging unit until the remaining amount becomes equal to or less than the predetermined value is accumulated and stored in the usage amount storage unit. Based on the usage amount of the developer accumulated and stored in the usage amount storage unit up to the time when the amount becomes the predetermined value or less, the cumulative amount is stored in the usage amount storage unit from the time when the remaining amount becomes the predetermined value or less. Correction coefficient calculation means for calculating a correction coefficient when converting the amount of the developer to be used,
The development remaining amount detecting means includes
Use of the developer used when the visible image is formed by the image forming means using the correction coefficient calculated by the correction coefficient calculating means when it is detected that the value is equal to or less than the predetermined value. 28. The double-sided printing control method according to claim 27, wherein the amount is corrected, and the corrected usage amount of the developer is accumulated and stored in the usage amount storage means. The development remaining amount detecting means includes
28. A display step of further displaying on the display section that the remaining amount of the developer has decreased when it is detected that the remaining amount of the developer has become a predetermined value or less. 30. The double-sided printing control method according to any one of items 1 to 29. The development remaining amount detecting means includes
And further performing a notification step of notifying the external communication device by the communication means that the remaining amount of the developer has decreased when it is detected that the remaining amount of the developer has become a predetermined value or less. The double-sided printing control method according to any one of claims 27 to 30, characterized in that: The double-sided transfer execution determination step includes
A developer usage amount for predicting a usage amount of the developer used when the control unit forms a visible image of both sides to be transferred onto the recording medium on the first image carrier by the transfer unit. Perform the prediction process,
By determining whether or not the remaining amount detected by the remaining developing amount detecting unit is equal to or greater than the usage amount of the developer predicted by the control unit in the developer usage amount prediction step, the control unit causes the remaining amount to be detected. Determining whether the amount is sufficient for transferring the visible image on both sides of the recording medium,
When the control unit determines that the remaining amount detected by the remaining developing amount detection unit is equal to or greater than the usage amount of the developer predicted by the control unit in the developer usage amount prediction step, the remaining amount is 25. The double-sided printing control method according to claim 24, wherein it is determined that an amount for transferring a visible image on both sides of the recording medium is secured. Means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less;
Means for detecting that the remaining amount of developer supplied to the image forming means has become a second predetermined value or less;
On both sides of the first image carrier, visible images of both sides transferred to the recording medium from when the remaining amount becomes equal to or less than a second predetermined value to when the remaining amount becomes equal to or less than the predetermined value. The amount of developer used at the time of formation is accumulated, and based on the accumulated amount of developer used, a visible image of both sides transferred to the recording medium is formed on the first image carrier. Correction coefficient calculation means for calculating a correction coefficient for predicting the usage amount of the developer used at the time,
The developer usage amount prediction step includes:
When it is detected that the value is equal to or less than the predetermined value, the control means uses the correction coefficient calculated by the correction coefficient calculation means to display a visible image of both sides transferred to the recording medium in the first 33. The double-sided printing control method according to claim 32, wherein the usage amount of the developer used when formed on the image carrier is corrected, and prediction is made based on the corrected usage amount of the developer. Means for detecting that the remaining amount of developer supplied to the image forming means has become a predetermined value or less;
Accumulating the amount of developer used when the visible images of both sides to be transferred to the recording medium are formed on the first image carrier by the time when the remaining amount becomes the predetermined value or less, When predicting the usage amount of the developer used when the visible images of both surfaces transferred to the recording medium are formed on the first image carrier based on the accumulated usage amount of the developer. Correction coefficient calculation means for calculating the correction coefficient of
The developer usage amount prediction step includes:
When it is detected that the value is equal to or less than the predetermined value, the control means uses the correction coefficient calculated by the correction coefficient calculation means to display a visible image of both sides transferred to the recording medium in the first 33. The double-sided printing control method according to claim 32, wherein the usage amount of the developer used when formed on the image carrier is corrected, and prediction is made based on the corrected usage amount of the developer.

Images