Image forming apparatus

Abstract

To provide an image forming apparatus that can effectively prevent a situation where an image carrier and an electrifying member are left standing in a contact state for a long period, while reducing power consumption.SOLUTION: An image forming apparatus 100 comprises: an image carrier (1); an image forming unit 50 that includes an electrifying member (21); a rotation driving unit 30 that drives to rotate the image carrier (1); a date acquisition unit 40 that acquires the date YMD; a receiving unit 60 that receives predetermined input information that is an operation of predetermined processing and / or a state or data; a control unit 200; and a storage unit 300. When a determination processing unit Q2 determines that the input detection date is the date later than the next rotation date, the control unit 200 performs predetermined distance rotation control of driving the rotation driving unit 30 to rotate the image carrier (1) by a predetermined moving distance and subsequently stopping the image carrier.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to an image forming apparatus such as a copying machine, a multifunction peripheral, a printer, and a facsimile machine.

Background Art

[0002] An image forming apparatus employing a contact charging method includes an image carrier such as a photoreceptor drum, a charging member such as a charging roller that contacts the image carrier to charge it, and a rotation driving unit that rotationally drives the image carrier. In such an image forming apparatus, if the image carrier and the charging member are left in a state of being in contact with each other for a long time, bleeding of chemical components from the charging member occurs, and the bled chemical components adhere to the image carrier, resulting in a linear image defect (a streak-like image defect along the rotation axis direction of the image carrier) in the formed image in the circumferential direction of the charging member and the image carrier.

[0003] Regarding this point, Patent Document 1 describes a configuration including a timing means for measuring the stop time during which the charging member (conductive member) and the image carrier (object to be charged) are stopped, and if the stop time measured by the timing means reaches a set stop time, the charging member and the image carrier are driven to prevent them from being left in a state of being in contact with each other for a long time.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration described in Patent Document 1, it is necessary to constantly supply power to the timing means in order to constantly monitor the stop time during which the charging member and the image carrier are stopped, which increases the power consumption accordingly.

[0006] Therefore, an object of the present disclosure is to provide an image forming apparatus that can effectively prevent the image carrier and the charging member from being left in contact with each other for a long time while suppressing power consumption.

Means for Solving the Problems

[0007] To solve the above problems, an image forming apparatus according to the present disclosure includes an image carrier, an image forming unit including a charging member that contacts the surface of the image carrier and charges the surface of the image carrier, a rotation driving unit that rotationally drives the image carrier, a date and time acquisition unit that acquires the date and time, a reception unit that receives predetermined input information that is an operation and / or state or data of a predetermined process, a control unit, and a storage unit. The control unit acquires, from the date and time acquisition unit, a rotation stop date and time that is the date and time when the rotation of the image carrier stops, and stores, in the storage unit, as a next rotation date and time, the date and time obtained by adding a predetermined addition period to the acquired rotation stop date and time. The control unit further includes a determination processing unit that, when the reception unit receives the predetermined input information, acquires the date and time from the date and time acquisition unit and determines whether the input detection date and time, which is the acquired date and time, is a date and time after the next rotation date and time stored in the storage unit. When the determination processing unit determines that the input detection date and time is a date and time after the next rotation date and time, the control unit performs a predetermined distance rotation control to drive the rotation driving unit to rotate the image carrier by a predetermined moving distance and then stop it.

Effects of the Invention

[0008] According to the present disclosure, it is possible to effectively prevent the image carrier and the charging member from being left in contact with each other for a long time while suppressing power consumption.

Brief Description of the Drawings

[0009]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0011] 〔Image Forming Apparatus〕 FIG. 1A is a cross-sectional view showing a schematic configuration of an example (100A) of an image forming apparatus 100 according to the present embodiment. FIG. 1B is a cross-sectional view showing a part of an image forming unit 50 in the image forming apparatus 100 (100A) shown in FIG. 1A. In the figure, reference symbol X indicates the left-right direction, reference symbol Y indicates the depth direction (front-rear direction), and reference symbol Z indicates the up-down direction.

[0012] The image forming apparatus 100(100A) is a multi-functional device having a copying function, a scanner function, a facsimile function, and a printer function, and transmits the image of the document G read by the image reading device 102 to the outside. Further, the image forming apparatus 100(100A) forms an image of the document G read by the image reading device 102 or an image received from the outside on a sheet P such as paper in color or monochrome by an electrophotographic method.

[0013] Above the image reading unit 130, a document feeder 190 that is supported so as to be openable and closable with respect to the image reading unit 130 is provided. The image reading device 102 includes the document feeder 190. The document feeder 190 conveys one or a plurality of documents G one by one in order to the document reading unit 130b. The document G conveyed one by one by the document feeder 190 is read by the image reading device 102 in the document reading unit 130b. Further, the image reading device 102 includes a document placing table 130a (document setting table) on which the document G is placed, and reads the document G placed on the document placing table 130a. The document placed on the document placing table 130a is read by the image reading device 102 by moving the scanning optical system 130c in the sub-scanning direction, which is a direction orthogonal to the scanning direction. As described above, the image reading device 102 reads the document G conveyed by the document feeder 190 in the document reading unit 130b to generate image data, or reads the document G placed on the document placing table 130a by moving the scanning optical system 130c in the sub-scanning direction to generate image data.

[0014] The image forming apparatus main body 101 includes a photosensitive drum 1 to 1 (an example of an image carrier) on which a toner image is formed, a charging device 2 to 2, a charging power supply 170 (see FIG. 1B) connected to the charging device 2 to 2, an exposure device 3 (a light scanning device), a developing device 4 to 4, a developing power supply 180 (see FIG. 1B) connected to the developing device 4 to 4, a primary transfer belt device 19 (an example of an intermediate transfer device), a primary transfer power supply 191 (see FIG. 1B) connected to the primary transfer belt device 19, a transfer device 11 (a secondary transfer device), a transfer power supply 192 (secondary transfer power supply) (see FIG. 1B) connected to the transfer device 11, a photosensitive cleaning device 5 to 5 for cleaning the photosensitive drum 1 to 1 after primary transfer, a fixing device 12, a sheet conveyance path S, a paper feed cassette 18, and sheet discharge trays 141, 141 (discharge unit 140).

[0015] As described above, the image forming apparatus 100 (100A) primarily transfers the toner image formed using a plurality of colors of toner to the primary transfer belt 71, and secondarily transfers the toner image primarily transferred to the primary transfer belt 71 to the sheet P.

[0016] In the present embodiment, image data corresponding to a color image using each of yellow (Y), magenta (M), and cyan (C), or a monochrome image using a single color [for example, black (K)] is handled. In the following description, yellow, magenta, cyan, and black are simply referred to as Y, M, C, and K, respectively.

[0017] The image forming apparatus 100 (100A) is provided with four photosensitive drums 1, charging devices 2, developing devices 4, and photosensitive cleaning devices 5 for forming four types of toner images, each of which is associated with Y, M, C, and K, and four image stations Pa, Pb, Pc, and Pd are configured.

[0018] The photoreceptor drums 1-1 have a grounded cylindrical conductive drum (an annular member such as aluminum) and a photosensitive layer formed on the outside of the cylindrical conductive drum, which exhibits insulation when not irradiated with light and changes to conductivity in the irradiated area when irradiated with light. That is, the surface 1a of the photoreceptor drums 1-1 is formed of the photosensitive layer. The photoreceptor drums 1-1 are rotationally driven in a predetermined direction via a drive transmission mechanism through which the rotational force from a rotation drive unit 30 (drive motor) (not shown) is transmitted. In other words, the photoreceptor drums 1-1 are rotationally driven in a predetermined direction R1 by the rotation drive unit 30 (see FIG. 1B).

[0019] The charging devices 2-2 each have a charging roller 21 that contacts each surface 1a of the photoreceptor drums 1-1. The charging roller 21 has a conductive elastic layer formed on the surface of a metal core, and the surface of the conductive elastic layer is provided so as to abut against the surface 1a of the photoreceptor drum 1. In the present disclosure, the contact area between the charging roller 21 and the surface 1a of the photoreceptor drum 1 may be referred to as a charging nip portion CN (charging nip region). The charging power supply 170 supplies a charging bias, which is a predetermined voltage or current for charging each surface 1a of the photoreceptor drums 1-1 to a predetermined potential, to the core of the corresponding charging roller 21. When the charging bias is supplied to the core of the charging roller 21, a minute discharge occurs near the contact portion between the charging roller 21 and the photoreceptor drum 1 due to the potential difference generated between the surface of the charging roller 21 and the photoreceptor drum 1, and the surface 1a of the photoreceptor drum 1 is charged to a predetermined potential. That is, the charging roller 21 contacts the surface 1a of the photoreceptor drums 1-1 and charges the surface 1a of the photoreceptor drums 1-1. The charging roller 21 is supported so as to rotate with the photoreceptor drums 1-1 when the corresponding photoreceptor drums 1-1 are rotationally driven in a predetermined direction by the rotation drive unit 30.

[0020] The exposure device 3 exposes the surface 1a (photosensitive layer) of the photoreceptor drums 1-1 charged to a predetermined potential by the charging devices 2-2 according to image data, and forms an electrostatic latent image in which the potential of the area where the image is formed is lower than the potential of the surface 1a of the photoreceptor drums 1-1.

[0021] The developing devices 4 to 4 develop the electrostatic latent images on the surfaces 1a of the photoreceptor drums 1 to 1, and form toner images on the surfaces 1a of the photoreceptor drums 1 to 1. The developing devices 4 to 4 contain a developer containing toner, and have a developing roller 41a on which the developer is carried at a position facing the photoreceptor drums 1 to 1. The developing power supply 180 supplies a developing bias, which is a predetermined voltage for supplying the toner contained in the developer carried on the developing roller 41a to the electrostatic latent images formed on the surfaces 1a of the photoreceptor drums 1 to 1. Further, the developing roller 41a is rotationally driven in a predetermined direction R2 via a drive transmission mechanism to which the rotational force from a rotational drive unit (not shown) is transmitted (see FIG. 1B). The rotational drive unit and the drive transmission mechanism for rotating the developing roller 41a may be shared with the rotational drive unit 30 and the drive transmission mechanism for rotating the photoreceptor drums 1 to 1 described above, or may be provided separately.

[0022] The photoreceptor cleaning devices 5 to 5 remove and recover the residual toner on the surfaces 1a of the photoreceptor drums 1 to 1 that has not been primarily transferred to the primary transfer belt 71 included in the primary transfer belt device 19 described later.

[0023] The primary transfer belt device 19 includes a primary transfer belt 71 (intermediate transfer belt), primary transfer rollers 6 to 6 (primary transfer members), a plurality of belt tension rollers 72 to 72, and a belt cleaning device 9.

[0024] The primary transfer belt 71 is stretched by belt stretching rollers 72 to 72. The belt stretching rollers 72 to 72 include a driving roller 721, a driven roller 722, and a plurality of tension rollers 723 to 723. The driving roller 721 is provided at one end (the right end side in this example) in the left-right direction X of the primary transfer belt device 19. The driven roller 722 is provided at the other end (the left end side in this example) in the left-right direction X of the primary transfer belt device 19. The driving roller 721 is rotationally driven in a predetermined direction R3 via a drive transmission mechanism to which a rotational force from a rotational drive unit (not shown) is transmitted (see FIG. 1B). When the driving roller 721 rotates, the primary transfer belt 71 moves (rotates) in a predetermined moving direction R. The driven roller 722 is rotationally driven following the movement of the primary transfer belt 71. The rotational drive unit and the drive transmission mechanism for rotating the primary transfer belt 71 may be shared with the rotational drive unit 30 and the drive transmission mechanism for rotating the photoreceptor drums 1 to 1 described above, or may be provided separately.

[0025] The primary transfer rollers 6 to 6 are each disposed inside the primary transfer belt 71 and are provided so as to bring the primary transfer belt 71 into contact with the corresponding photoreceptor drums 1 to 1. The primary transfer power source 191 supplies a primary transfer bias, which is a voltage or current for transferring the four types of toner images formed on the surface 1a of the photoreceptor drums 1 to 1 corresponding to each color, to the primary transfer rollers 6 to 6. When the primary transfer bias is supplied, the primary transfer rollers 6 to 6 primarily transfer the toner images formed on the surface 1a of the photoreceptor drums 1 to 1 to the primary transfer belt 71. The belt cleaning device 9 removes and collects the waste toner remaining on the surface 71a of the primary transfer belt 71 without being transferred to the sheet P by the transfer device 11 described later.

[0026] The transfer device 11 has a transfer roller 11a that contacts the primary transfer belt 71 and rotates passively when the primary transfer belt 71 rotates. The transfer roller 11a sandwiches and conveys the sheet P conveyed through the sheet conveyance path S at the transfer nip portion TN (transfer nip region), which is the contact portion with the primary transfer belt 71. The transfer power supply 192 supplies a transfer bias, which is a predetermined voltage or current for secondarily transferring the toner image primarily transferred onto the surface of the primary transfer belt 71 to the sheet P, to the transfer roller 11a. When the transfer bias is supplied, the transfer roller 11a secondarily transfers the toner image on the surface 71a of the primary transfer belt 71 to the sheet P passing through the transfer nip portion TN. The sheet P onto which the toner image has been secondarily transferred at the transfer nip portion TN is conveyed to the fixing device 12.

[0027] The fixing device 12 includes a fixing roller 31 and a pressure roller 32 that rotate with the sheet P sandwiched therebetween. The fixing roller 31 or the pressure roller 32 is heated to a predetermined temperature by a heat source (not shown). The fixing device 12 sandwiches the sheet P onto which the toner image has been transferred between the fixing roller 31 and the pressure roller 32, heats and pressurizes it, and fixes the toner image to the sheet P with heat and pressure. Either the fixing roller 31 or the pressure roller 32 is rotationally driven in a predetermined direction via a drive transmission mechanism to which the rotational force from a rotation drive unit 30 (not shown) is transmitted. The rotation drive unit and the drive transmission mechanism for rotating either the fixing roller 31 or the pressure roller 32 may be shared with the rotation drive unit 30 and the drive transmission mechanism for rotating the photosensitive drums 1 to 1 described above, or may be provided separately. Also, the heat source (not shown) is supplied with the electric power necessary for heat generation from a fixing power supply (not shown).

[0028] As described above, the image forming apparatus 100 (100A) includes an image forming unit 50 including the photosensitive drums 1 to 1, the charging devices 2 to 2, the exposure device 3, the developing devices 4 to 4, the primary transfer belt device 19, the transfer device 11, the photosensitive cleaning devices 5 to 5, and the fixing device 12. It can be said that the image forming unit 50 includes at least the photosensitive drums 1 to 1 and the charging roller 21 that contacts the surface 1a of the photosensitive drums 1 to 1 and charges the surface 1a of the photosensitive drums 1 to 1.

[0029] The paper feed cassette 18 is for accumulating the sheets P used for image formation, and is provided below the exposure device 3.

[0030] In the image forming apparatus 100(100A), when performing image formation (printing), the sheet P drawn from the paper feed cassette 18 by the pickup roller 16 is conveyed to the registration roller 14 by the conveying roller 13 provided along the sheet conveyance path S. Next, the sheet P is conveyed at a timing when it is aligned with the toner image on the primary transfer belt 71, and the toner image on the photosensitive drum 1 is transferred onto the sheet P by the transfer device 11. After that, the unfixed toner on the sheet P is fixed by the fixing device 12, and is discharged onto the sheet discharge tray 141 via the conveying roller 13 and the discharge roller 17. Also, when performing image formation (printing) not only on the front surface but also on the back surface of the sheet P, the sheet P is conveyed in the reverse direction from the discharge roller 17 to the sheet inversion path Sr, the front and back of the sheet P are inverted, and it is guided again to the registration roller 14. In the same manner as the front surface of the sheet P, an image is formed on the back surface of the sheet P and it is carried out to the sheet discharge tray 141. Here, the pickup roller 16, the conveying roller 13, the registration roller 14, and the discharge roller 17 are rotationally driven in a predetermined direction via a drive transmission mechanism to which the rotational force from a rotational drive unit (drive motor) (not shown) is transmitted. The rotational drive unit and the drive transmission mechanism for rotating the developing roller 41a may be shared with the rotational drive unit and the drive transmission mechanism for rotating the photosensitive drums 1 to 1 described above, or may be provided separately.

[0031] In the example shown in Fig. 1A, there is one paper feed cassette 18, but the present invention is not limited to this, and a configuration in which a plurality of paper feed cassettes 18 are provided, and different types of sheets P may be loaded in each of them.

[0032] FIG. 2A is a schematic cross-sectional view of another example (100B) of the image forming apparatus 100 according to the present embodiment, viewed from the front. FIG. 2B is a schematic cross-sectional view showing the image forming unit 50 in the image forming apparatus 100 (100B) shown in FIG. 2A. In the image forming apparatus 100 (100B) shown in FIG. 2A, components substantially the same as those in the image forming apparatus 100 (100A) shown in FIG. 1A are denoted by the same reference numerals, and their descriptions are omitted.

[0033] The image forming apparatus 100 (100B) shown in FIG. 2A is an image forming apparatus that forms a monochrome image on the sheet P by an electrophotographic method according to the image data read by the image reading device 102 or the image data transmitted from the outside. Therefore, it is different from the image forming apparatus 100 (100A) shown in FIG. 1A in that it cannot form a color image on the sheet P, that is, it does not include a plurality of photosensitive drums 1, and that it does not include the primary transfer belt device 19. Therefore, next, the transfer device 11 for directly transferring the toner image formed on the surface 1a of the photosensitive drum 1 to the sheet P will be described.

[0034] The transfer device 11 has a transfer roller 11a that contacts the surface 1a of the photosensitive drum 1. The transfer roller 11a forms a transfer nip portion TN (transfer nip region) between the transfer roller 11a and the photosensitive drum 1 (an example of an image forming body), and sandwiches and conveys the sheet P conveyed through the sheet conveyance path S in the transfer nip portion TN. The transfer roller 11a rotates passively when the photosensitive drum 1 rotates. The transfer power source 192 supplies a transfer bias, which is a predetermined voltage or current for electrostatically moving the toner image formed on the surface 1a of the photosensitive drum 1 to the sheet P, to the transfer roller 11a. The toner image formed on the surface 1a of the photosensitive drum 1 is electrostatically transferred by the transfer bias supplied from the transfer power source 192 when the sheet P passes through the transfer nip portion TN.

[0035] In the image forming apparatus 100 (100B), when performing image formation (printing), the sheet P drawn out from the paper feed tray 8 by the pickup roller 16 is conveyed to the registration roller 14 by the conveying roller 13 provided along the sheet conveyance path S. Next, the sheet P is conveyed at a timing that aligns the sheet P with the toner image on the photosensitive drum 1, and the toner image on the photosensitive drum 1 is transferred onto the sheet P by the transfer device 11. Thereafter, the unfixed toner on the sheet P is fixed by the fixing device 12 and discharged onto the sheet discharge tray 141 via the conveying roller 13 and the discharge roller 17.

[0036] In this way, the image forming apparatus 100 (100A, 100B) completes a series of printing operations. Note that the image forming apparatus 100 (100A, 100B) is hereinafter simply referred to as the image forming apparatus 100.

[0037] As described above, the image forming apparatuses 100 (100A, 100B) are common in that they each include a charging roller 21 that contacts the surface 1a of the photosensitive drum 1 in order to charge the surface 1a of the photosensitive drum 1 to a predetermined potential. In other words, the image forming apparatuses 100 (100A, 100B) have a charging roller 21 that abuts against the surface 1a of the photosensitive drum 1 and charges the surface 1a of the photosensitive drum 1.

[0038] As described above, in the present embodiment, the image forming apparatus 100 includes an image carrier (the photosensitive drum 1 in this example), a charging member (the charging roller 21 in this example) that contacts and charges the surface 1a of the photosensitive drum 1, and a rotation driving unit 30 (driving motor) that rotationally drives the photosensitive drum 1. In this example, the charging roller 21 rotates (rotates passively) together with the photosensitive drum 1 when the photosensitive drum 1 is rotated by the rotation driving unit 30.

[0039] Here, the charging roller 21 has a conductive elastic layer 21a formed on the outer peripheral surface of a conductive rotating shaft 21b (conductive support). As the material of the rotating shaft 21b, for example, a round bar of a metal material such as iron, copper, stainless steel, aluminum, or nickel can be used.

[0040] As the material of the elastic layer 21a, for example, natural rubber, ethylene propylene rubber (EPDM), styrene butadiene rubber (SBR), silicone rubber, urethane rubber, epichlorohydrin rubber, isoprene rubber (IR), butadiene rubber (BR), nitrile butadiene rubber (NBR), chloroprene rubber (CR), or other synthetic rubbers, or an elastic material such as polyamide, urethane resin, or silicone resin, with a conductive agent having an electronic conduction mechanism such as carbon black, graphite, or a conductive metal oxide, and a conductive agent having an ionic conduction mechanism such as an alkali metal salt or a quaternary ammonium salt appropriately added thereto can be used.

[0041] Note that a resistance layer may be provided on the surface of the elastic layer 21a to adjust the electric resistance of the entire charging roller 21. As the resistance layer, a material having conductivity or semiconduction can be used.

[0042] By the way, in the image forming apparatus 100, when the photosensitive drum 1 and the charging roller 21 are in contact with each other and left stationary for a long time, bleeding of the chemical components of additives such as softening oil and plasticizer contained in the elastic layer 21a from the surface of the charging roller 21 occurs, and the chemical components of the bled additives adhere to the photosensitive drum 1, resulting in a linear image defect (a streak-like image defect along the rotation axis direction of the photosensitive drum 1) in the formed image in the circumferential direction of contact between the charging roller 21 and the photosensitive drum 1.

[0043] Here, in the prior art, a time-lapse means for measuring the time elapsed since the photosensitive drum 1 stopped was provided, and the photosensitive drum 1 was rotated when the stop time during which the photosensitive drum 1 was stopped reached the set stop time, so that the photosensitive drum 1 and the charging roller 21 would not be in contact with each other at the same position for a long time. Therefore, the image forming apparatus 100 has a problem that it is necessary to continuously supply power to a control unit, a drive source for driving the photosensitive drum 1, etc. for measuring the elapsed time by the time-lapse means, resulting in excessive power consumption.

[0044] (First Embodiment) In this embodiment, while suppressing the power consumption after the photoreceptor drum 1 has stopped, the system configuration is such that the photoreceptor drum 1 and the charging roller 21 do not come into contact with each other at the same position for a long time. This system configuration will be described with reference to FIG. 3.

[0045] FIG. 3 is a schematic block diagram showing the system configuration of the image forming apparatus 100 according to the first embodiment.

[0046] As shown in FIG. 3, the image forming apparatus 100 further includes a date and time acquisition unit 40 (clock unit), a reception unit 60, a control unit 200, and a storage unit 300. The date and time acquisition unit 40 has a clock function including a calendar function and is a clock that measures the date and time YMD. The reception unit 60 includes an operation reception unit 70 (operation panel) for the operator to select and execute the processes performed by the image forming apparatus 100, a communication unit 80 for communicating with the Internet or the like, a human presence detection unit (human presence sensor) 90 for detecting that the operator has approached the image forming apparatus 100, and a detection unit 61 for detecting whether there is an input from these, that is, whether a predetermined input information IN which is a predetermined process, state, or data has been received. That is, the reception unit 60 is configured to receive the operation of a predetermined process and / or the state or data which is the predetermined input information IN. The date and time acquisition unit 40 and the detection unit 61 are respectively connected to the input system of the control unit 200, and the rotation drive unit 30 and the image forming unit 50 are connected to the output system of the control unit 200. Note that the date and time acquisition unit 40 is configured to operate even when the main body power supply (control power supply 150 described later) is in the OFF state by a backup power supply such as a detachable or rechargeable battery.

[0047] As shown in FIG. 3, the control unit 200 includes a processing unit 201 composed of a computer such as a CPU (Central Processing Unit), and a storage unit 300 including a non-volatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory). The control unit 200 causes the processing unit 201 to load a control program stored in advance in the ROM of the storage unit 300 onto the RAM of the storage unit 300 and execute it, so that the operation control (control processing) of various components is performed in the processing unit 201. The storage unit 300 is connected to the processing unit 201. Note that the control unit 200 can perform the operation control of various components by receiving power supply from the control power supply 150.

[0048] The processing unit 201 of the control unit 200 includes an arithmetic processing unit Q1, a determination processing unit Q2, a rotation control unit Q3, and a power supply control unit Q4.

[0049] The arithmetic processing unit Q1 acquires from the date and time acquisition unit 40 the rotation stop date and time, which is the date and time YMD at the time when the rotation control unit Q3 stops the rotation of the photosensitive drum 1, and stores in the storage unit 300, as the next rotation date and time Rt, the date and time obtained by adding a predetermined addition period T1 (the time or number of days to rotate next, for example, 5 days) to the rotation stop date and time acquired from the date and time acquisition unit 40. This addition period T1 is a period during which no image defect occurs even if chemical components ooze out from the charging roller 21 while the photosensitive drum 1 is left stopped. This addition period T1 is obtained by experiments and is stored in the storage unit 300 in advance.

[0050] The determination processing unit Q2 acquires from the date and time acquisition unit 40 the input detection date and time Tw, which is the date and time YMD at the time when the detection unit 61 detects that it has received the input information IN, and determines whether or not the acquired input detection date and time Tw is a date and time after the next rotation date and time Rt stored in the storage unit 300. In other words, when the reception unit 60 receives the predetermined input information IN, the determination processing unit Q2 acquires the date and time from the date and time acquisition unit 40 and determines whether or not the input detection date and time Tw, which is the acquired date and time, is a date and time after the next rotation date and time Rt stored in the storage unit 300.

[0051] When the rotation control unit Q3 determines that the input detection date and time Tw is a date and time after the next rotation date and time Rt in the determination processing unit Q2, the rotation drive unit 30 rotates the photosensitive drum 1 by a predetermined moving distance (surface moving distance, rotation angle), and after rotating by the predetermined moving distance, performs a predetermined distance rotation control to stop. In other words, when the determination processing unit Q2 determines that the input detection date and time Tw is a date and time after the next rotation date and time Rt, the control unit 200 drives the rotation drive unit 30 to rotate the photosensitive drum 1 by a predetermined moving distance and then performs a predetermined distance rotation control to stop.

[0052] As described above, according to the present embodiment, the next rotation date and time Rt obtained by adding the predetermined addition period T1 to the rotation stop date and time, which is the date and time YMD measured by the date and time acquisition unit 40 when the rotation of the photosensitive drum 1 stops, is calculated and stored in the storage unit 300, so that the elapsed time from the date and time when the input information IN is received can be determined. That is, unlike the conventional configuration, it is not necessary to constantly supply power to the timing means to constantly monitor the stop time during which the charging roller 21 and the photosensitive drum 1 are stopped, and thus the power consumption can be suppressed. Moreover, it is determined whether the input detection date and time Tw, which is the date and time YMD acquired by the date and time acquisition unit 40 when it is detected that the input information IN has been received, is a date and time after the next rotation date and time Rt stored in the storage unit 300. When it is determined that the input detection date and time Tw is a date and time after the next rotation date and time Rt, the rotation drive unit 30 rotates the photosensitive drum 1 by a predetermined moving distance. Therefore, the contact position between the photosensitive drum 1 and the charging roller 21 can be shifted, and thereby, it is possible to effectively prevent the photosensitive drum 1 and the charging roller 21 from being left in a state of being in contact for a long time. Note that the input detection date and time Tw acquired by the date and time acquisition unit 40 may be acquired from a date and time information providing service provided via the Internet through the communication unit 80.

[0053] (First Embodiment - 1) In the present embodiment, the control unit 200 rotates the photosensitive drum 1 by a predetermined moving distance with the rotation control unit Q3. When the rotation is completed, the calculation processing unit Q1 calculates the next rotation date and time Rt and updates the old next rotation date and time Rt stored in the storage unit 300 with the newly calculated next rotation date and time Rt by the calculation processing unit Q1. That is, the value of the next rotation date and time Rt stored in the storage unit 300 is overwritten and saved for update. In other words, when the predetermined distance opening control is performed and the photosensitive drum 1 stops, the calculation processing unit Q1 calculates the next rotation date and time Rt and stores it in the storage unit 300.

[0054] By doing so, it is possible to update to the latest next rotation date and time Rt.

[0055] (First Embodiment - 2) By the way, when rotating the photosensitive drum 1 when detecting that the input information IN has been received, that is, when the rotation control unit Q3 rotates the photosensitive drum 1 based on the determination result of the determination processing unit Q2, the outer surface of the charging roller 21 that is in contact with the photosensitive drum 1 can be rotated and moved away from the area in contact with the charging roller 21 of the photosensitive drum 1. For this purpose, since the charging roller 21 rotates with the photosensitive drum 1 as described above, it is only necessary to move the photosensitive drum 1 by a predetermined distance or more in the circumferential direction of the photosensitive drum 1 in the charging nip portion, and it is not necessary to rotate the charging roller 21 once.

[0056] As a specific predetermined moving distance, it can be exemplified that it exceeds 1 time (for example, 2 times or more) and is about 5 times or less, preferably about 2.5 times to 4 times, of the contact width (for example, about 1 mm to 3 mm) in the circumferential direction of the contact portion between the charging roller 21 and the photosensitive drum 1. By moving in this way, the area of the photosensitive drum 1 that the charging roller 21 has been in contact with moves from the position of the charging nip portion CN, so that the chemical components oozing out from the charging roller 21 are no longer supplied. By repeating such movement when a predetermined standing time or more has elapsed, it is possible to prevent the chemical components oozing out from the charging roller 21 from being concentrated and supplied to a part of the photosensitive drum 1. Further, by rotating the photosensitive drum 1 when it is detected that the input information IN has been received, the power consumption required for the rotation operation can be minimized.

[0057] (First Embodiment - 3) In the present embodiment, the image forming apparatus 100 further includes a control power supply 150 that supplies the control unit 200 with the power necessary for the control unit 200 to operate, and an operation power supply 160 that supplies the power necessary for operating the image forming unit 50 and the rotation drive unit 30. The control power supply 150 is connected to the control unit 200 and supplies the control unit 200 with the power necessary for operation. The control unit 200 can selectively execute a first mode MD1 [operation preparation (ready) mode] in which image forming processing is possible, and a second mode MD2 (energy saving mode) with lower power consumption than the first mode MD1.

[0058] In the first mode MD1, the control unit 200 turns on the operating power supply 160 to supply the first power consumption required for the image forming process. In the second mode MD2, the control unit 200 turns off the operating power supply 160 and supplies the second power consumption, which is smaller than the first power consumption, from the control power supply 150 to perform non-image forming operations other than the image forming operation (non-rotation operation of the photosensitive drum 1). That is, the control unit 200 can selectively execute the first mode MD1 in which power is supplied from the control power supply 150 to the control unit 200 and power is supplied from the operating power supply 160 to the image forming unit 50 and the rotation driving unit 30, and the second mode MD2 in which power is supplied from the control power supply 150 to the control unit 200 and the operating power supply 160 is turned off. Here, examples of the non-image forming operations include facsimile reception and transmission, and / or reception operations of image signals from a personal computer, a mobile terminal, and / or a printing server.

[0059] The control power supply 150 constantly supplies power to the control unit 200 and selectively switches between the first mode MD1 and the second mode MD2 according to an instruction signal from the control unit 200. The switching between the first mode MD1 and the second mode MD2 by the control unit 200 is performed as follows. That is, the processing unit 201 of the control unit 200 executes the first mode MD1 during a predetermined standby period T2 (for example, 1 minute), which is a period shorter than the addition period T1 (for example, 5 days), from when the rotation of the photosensitive drum 1 stops due to processing such as image formation processing (that is, the rotation stop date and time). When the reception unit 60 does not receive the predetermined input information IN during the standby period T2, the second mode MD2 is executed. Then, when the reception unit 60 receives the input information IN during the execution of the second mode MD2, a determination is made as to whether or not to perform predetermined distance rotation control by the determination processing unit Q2. In other words, the control unit 200 executes the first mode MD1 during the standby period T2, which is a period shorter than the predetermined addition period T1 from the rotation stop date and time. When the reception unit 60 does not receive the predetermined input information IN during the standby period T2, the second mode MD2 is executed. When the reception unit 60 receives the input information IN during the execution of the second mode MD2, a determination is made by the determination processing unit Q2. Here, since the detection unit 61 is receiving power supply from the control power supply 150, it can detect whether or not the input information IN has been received even when the second mode MD2 is selected.

[0060] By doing so, in the second mode MD2, where the power consumption is smaller than that in the first mode MD1, the detection unit 61 detects whether or not the input information IN has been received. Thus, the input information IN is detected while suppressing the power consumption, and by determining that the input detection date and time Tw is a date and time after the next rotation date and time Rt, the photosensitive drum 1 can be rotated by a predetermined moving distance by the rotation drive unit 30. Therefore, it is possible to effectively prevent the photosensitive drum 1 and the charging roller 21 from being left in contact with each other for a long time while further suppressing the power consumption.

[0061] (First Embodiment - 4) Incidentally, in the case of an image forming operation or the like, the photosensitive drum 1 may be rotated longer than a predetermined distance for moving the photosensitive drum 1 during the execution of the second mode MD2. Also in this case, the contact position between the photosensitive drum 1 and the charging roller 21 can be shifted.

[0062] Therefore, in the present embodiment, when the rotation control unit Q3 rotates the photosensitive drum 1 longer than a predetermined moving distance (for example, in the case of an image forming operation), the arithmetic processing unit Q1 calculates the next rotation date and time Rt when the rotation of the photosensitive drum 1 stops, and updates the next rotation date and time Rt by rewriting the storage in the storage unit 300. More specifically, when the input information IN is an execution (information) of an image forming process, the rotation drive unit 30 is controlled without performing the rotation control for a predetermined distance, the photosensitive drum 1 is rotated, an image is formed by the image forming unit 50, and when the photosensitive drum 1 is stopped after the end of the image forming process, the arithmetic processing unit Q1 calculates the next rotation date and time Rt and stores it in the storage unit 300 to update the next rotation date and time Rt.

[0063] By doing so, even in the case of an image forming operation or the like, the next rotation date and time Rt can be updated to the latest one.

[0064] (First Embodiment - 5) Incidentally, examples of the detection trigger for detecting the input information IN by the detection unit 61 include reception of input operation information indicating an input operation by an operator, reception of communication information from the outside, reception of detection information indicating that a person has approached, and the like.

[0065] Specifically, the image forming apparatus 100 according to the present embodiment includes an operation reception unit 70 (operation panel) that receives an input of operation information indicating an input operation by an operator. The operation reception unit 70 includes a touch-type liquid crystal panel and hardware keys such as numeric keys. The operation reception unit 70 is connected to the detection unit 61 and transmits the operation information to the detection unit 61. As a result, the detection unit 61 can detect the operation information from the operation reception unit 70. The input information IN includes non-rotation operation information IS that does not rotate the photoreceptor drum 1 among the operation information received by the operation reception unit 70, and execution information of the image forming process for causing the image forming unit 50 to form an image.

[0066] Here, examples of the non-rotation operation include pressing operations of hardware keys that are not involved in the rotation of the photoreceptor drum 1 of the operation reception unit 70 (for example, pressing operations on numeric keys, mode switching key operations for entering the energy saving mode, original reading operations in the image reading unit 130, etc.).

[0067] By doing so, the detection unit 61 can easily detect the input information IN including the non-rotation operation information IS using the existing operation reception unit 70.

[0068] (First Embodiment - 6) The image forming apparatus 100 according to the present embodiment includes a communication unit 80 that receives an input of communication information IM from the outside. The communication unit 80 is connected to the detection unit 61 and transmits the communication information IM received by the communication unit 80 to the detection unit 61. As a result, the detection unit 61 can detect the communication information IM from the communication unit 80.

[0069] Here, examples of the communication information IM include, for example, when the communication unit 80 is connected to a public line, and / or the Internet, and / or a wireless LAN, image information from a facsimile apparatus, and / or a personal computer, and / or a print server.

[0070] In this way, by using the communication unit 80 that receives the input of communication information IM from the outside, the detection unit 61 can easily detect the input information IN including the communication information IM.

[0071] (First Embodiment - 7) The image forming apparatus 100 according to the present embodiment includes a human presence detection unit 90 (human presence sensor) that detects that a person has approached. The human presence detection unit 90 is connected to the detection unit 61, and transmits human presence detection information IH indicating that a person has been detected by the human presence detection unit 90 to the detection unit 61. Thereby, the detection unit 61 can detect the human presence detection information IH from the human presence detection unit 90. The input information IN includes the human presence detection information IH.

[0072] By doing so, it is possible to easily detect the input information IN including the human presence detection information IH by using the human presence detection unit 90 that detects that a person has approached.

[0073] FIG. 4 is a flowchart showing an example of a control operation for rotationally controlling the photosensitive drum 1 in the first embodiment.

[0074] In the flowchart shown in FIG. 4, first, when the control unit 200 detects that the rotation of the photosensitive drum 1 has stopped (S1: Yes), it acquires the current date and time from the date and time acquisition unit 40, calculates the next rotation date and time Rt by the arithmetic processing unit Q1 (S2), and stores the next rotation date and time Rt in the storage unit 300 (S3).

[0075] Next, the control unit 200 determines whether a print job has been received (S4). If it is determined that no print job has been received (S4: No), it determines whether the detection unit 61 has detected the input information IN (S5). In a state where the control unit 200 has not detected the input information IN (S5: No), it proceeds to S4. On the other hand, when the control unit 200 determines that the input information IN has been detected (S5: Yes), it acquires the input detection date and time Tw from the date and time acquisition unit 40 (S6), acquires the next rotation date and time Rt from the storage unit 300 (S7), and determines whether the input detection date and time Tw is after the next rotation date and time Rt by the determination processing unit Q2 (S8).

[0076] When the control unit 200 determines that the input detection date and time Tw has not reached the next rotation date and time Rt (S8: No), it proceeds to S4. On the other hand, when the control unit 200 determines that the input detection date and time Tw is after the next rotation date and time Rt (S8: Yes), the rotation control unit Q3 rotates the photoreceptor drum 1 by a predetermined moving distance by the rotation driving unit 30 (S9), and proceeds to S1.

[0077] Also, when the control unit 200 determines that a print job has been received (S4: Yes), the image forming unit 50 performs an image forming operation (S10), and proceeds to S1.

[0078] (Second Embodiment) FIG. 5 is a schematic block diagram showing a system configuration for rotationally controlling the photoreceptor drum 1 in the image forming apparatus 100 according to the second embodiment. FIG. 6 is a flowchart showing an example of a control operation for rotationally controlling the photoreceptor drum 1 in the second embodiment.

[0079] In the image forming apparatus 100 according to the present embodiment, in order to reduce the power consumption in a state where the image forming process is left undone, the control unit 200 is composed of two control units (the first control unit 210 and the second control unit 220). One control unit (the first control unit 210) is for performing non-image forming processes, which are processes other than the image forming process, and the other control unit (the second control unit 220) is for controlling the image forming unit 50 to perform the image forming process. And when a standby period T2, which is a predetermined time after the completion of the image forming process, elapses, the first control unit 210, which is one of the control units, is configured to cut off the power supply to the second control unit 220, which is the other control unit.

[0080] In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0081] As shown in FIG. 5, the control unit 200 includes a first control unit 210 (system control unit) for performing non-image forming processing, which is processing other than image forming processing, and a second control unit 220 (engine control unit) for performing image forming processing. The processing unit 201 includes a first processing unit 211 (ICU: Image Control Unit) and a second processing unit 221 (PCU: Process Roll Unit). The storage unit 300 includes a first storage unit 310 for performing non-image forming operations, which are operations other than image forming processing, and a second storage unit 320 for performing image forming operations. The date and time acquisition unit 40 and the detection unit 61 are connected to the input system of the first control unit 210. The rotation drive unit 30 and the image forming unit 50 are connected to the output system of the second control unit 220. In addition, a communication unit, an image processing unit, etc., not shown, are connected to the first control unit 210 in addition to the detection unit 61 and the date and time acquisition unit 40. In addition to the rotation drive unit 30 and the image forming unit 50, an operation power source 160 (drive power control unit, process power control unit, etc.) is connected to the second control unit 220.

[0082] As shown in FIG. 5, the first control unit 210 and the second control unit 220 each include a first processing unit 211 and a second processing unit 221 composed of a computer such as a CPU, and a first storage unit 310 and a second storage unit 320 including non-volatile memories such as ROM and volatile memories such as RAM. The first control unit 210 and the second control unit 220 are each configured to control the operation of various components by loading a control program stored in advance in the ROM of the first storage unit 310 and the second storage unit 320 onto the RAM of the first storage unit 310 and the second storage unit 320 and executing it by the first processing unit 211 and the second processing unit 221. The first storage unit 310 and the second storage unit 320 are each connected to the first processing unit 211 and the second processing unit 221. The control power supply 150 is connected to both the first control unit 210 and the second control unit 220.

[0083] The first control unit 210 includes an arithmetic processing unit Q1, a determination processing unit Q2, and a power supply control unit Q4. The second control unit 220 includes a rotation control unit Q3. The arithmetic processing unit Q1 stores the next rotation date and time Rt in the first storage unit 310.

[0084] When the first mode MD1 is selected, the power control unit Q4 controls the control power supply 150 to supply power to both the first control unit 210 and the second control unit 220. When the second mode MD2 is selected, the power control unit Q4 controls the control power supply 150 to supply power only to the first control unit 210 among the first control unit 210 and the second control unit 220. That is, the control power supply 150 always supplies power to the first control unit 210 in the first mode MD1 and the second mode MD2, and selectively switches between the first mode MD1 and the second mode MD2 according to the instruction signal from the power control unit Q4.

[0085] In the flowchart shown in FIG. 6, in the first mode MD1, when the first control unit 210 detects that the rotation of the photoreceptor drum 1 has stopped (S1: Yes), the arithmetic processing unit Q1 calculates the next rotation date and time Rt (S2), and stores the next rotation date and time Rt in the first storage unit 310 (S3).

[0086] Thereafter, it is determined whether a print job has been received (S4). If the state where the first control unit 210 (power control unit Q4) has not received a print job continues for a predetermined time (for example, 1 minute) shorter than the addition period, it switches to the second mode MD2 (energy saving mode).

[0087] The first control unit 210 determines whether the detection unit 61 has detected the input information IN (S5). When the first control unit 210 has not detected the input information IN (S5: No), it proceeds to S4. On the other hand, when the first control unit 210 determines that the input information IN has been detected (S5: Yes), it acquires the input detection date and time Tw from the date and time acquisition unit 40 (S6), acquires the next rotation date and time Rt from the first storage unit 310 (S7), and the determination processing unit Q2 determines whether the input detection date and time Tw is after the next rotation date and time Rt (S8).

[0088] When the first control unit 210 determines that the input detection date / time Tw has not reached the next rotation date / time Rt (S8: No), it proceeds to S4. On the other hand, when the first control unit 210 determines that the input detection date / time Tw is a date / time after the next rotation date / time Rt (S8: Yes), it switches to the first mode MD1 and supplies power to the second control unit 220. The second control unit 220 rotates the photosensitive drum 1 by a predetermined moving distance (rotation angle) by the rotation drive unit 30 with the rotation control unit Q3 (S9). When the rotation of the photosensitive drum 1 by the second control unit 220 is completed, the first control unit 210 controls the power supply control unit Q4 to switch back to the second mode MD2 and proceeds to S1.

[0089] Also, when the first control unit 210 determines that it has received a print job (S4: Yes), in the second mode MD2, it controls the power supply control unit Q4 to switch to the first mode MD1, and the second control unit 220 performs an image forming operation in the image forming unit 50 (S10).

[0090] By doing so, it is possible to effectively prevent the photosensitive drum 1 and the charging roller 21 from being left in contact with each other for a long time while further suppressing power consumption by using the first control unit 210 for non-image forming operations.

[0091] (Third Embodiment) In the second embodiment, the first control unit 210 stores the next rotation date / time Rt in the first storage unit 310. However, in the third embodiment, the second control unit 220 stores the next rotation date / time Rt in the second storage unit 320.

[0092] FIG. 7 is a schematic block diagram showing a system configuration for controlling the rotation of the photosensitive drum 1 in the image forming apparatus 100 according to the third embodiment. FIG. 8 is a flowchart showing an example of a control operation for controlling the rotation of the photosensitive drum 1 in the third embodiment.

[0093] In the third embodiment, substantially the same components as those in the first and second embodiments are denoted by the same reference numerals, and their descriptions are omitted.

[0094] As shown in FIG. 7, the first control unit 210 includes a determination processing unit Q2 and a power supply control unit Q4. The second control unit 220 includes an arithmetic processing unit Q1 and a rotation control unit Q3, and causes the second storage unit 320 to store the next rotation date and time Rt.

[0095] Similar to the second embodiment, the control power supply 150 supplies power to both the first control unit 210 and the second control unit 220 when the first mode MD1 is selected, and supplies power only to the first control unit 210 among the first control unit 210 and the second control unit 220 when the second mode MD2 is selected.

[0096] In the flowchart shown in FIG. 8, in the first mode MD1, when the second control unit 220 detects that the rotation of the photosensitive drum 1 has stopped (S1: Yes), the arithmetic processing unit Q1 calculates the next rotation date and time Rt (S2), and stores the next rotation date and time Rt in the second storage unit 320 (S3).

[0097] Next, it is determined whether a print job has been received (S4). When the first control unit 210 (power supply control unit Q4) continues a predetermined standby period in a state where no print job has been received, it switches to the second mode MD2 (energy saving mode).

[0098] The first control unit 210 determines whether the detection unit 61 has detected the input information IN (S5). When the first control unit 210 has not detected the input information IN (S5: No), it proceeds to S4. On the other hand, when the first control unit 210 determines that the input information IN has been detected (S5: Yes), it switches to the first mode MD1. Then, the first control unit 210 acquires the input detection date and time Tw from the date and time acquisition unit 40 (S6), acquires the next rotation date and time Rt from the second storage unit 320 of the second control unit 220 (S7), and the determination processing unit Q2 determines whether the input detection date and time Tw is after the next rotation date and time Rt (S8).

[0099] When the first control unit 210 determines that the input detection date and time Tw has not reached the next rotation date and time Rt (S8: No), it proceeds to S4. On the other hand, when the first control unit 210 determines that the input detection date and time Tw is a date and time after the next rotation date and time Rt (S8: Yes), the second control unit 220 rotates the photosensitive drum 1 by a predetermined moving distance (rotation angle) by the rotation drive unit 30 in the rotation control unit Q3 (S9), and proceeds to S1.

[0100] In this way, by using the first control unit 210 for performing non-image forming operations and the second control unit 220 for performing image forming operations, it is possible to effectively prevent the photosensitive drum 1 and the charging roller 21 from being left in a state of long-term contact while further suppressing power consumption.

[0101] The present disclosure is not limited to the embodiments described above, and can be implemented in various other forms. Therefore, such embodiments are merely illustrative in all respects and should not be construed in a limiting manner. The scope of the present disclosure is indicated by the claims and is not restricted by the text of the specification. Furthermore, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present disclosure.

Explanation of Reference Numerals

[0102] 1 Photosensitive drum (an example of an image carrier) 2 Charging device 30 Rotation drive unit 40 Date and time acquisition unit 50 Image forming unit 21 Charging roller (an example of a charging member) 60 Reception unit 70 Operation reception unit 80 Communication unit 90 Human presence detection unit 100 Image forming apparatus 150 Control power supply 160 Operation power supply 200 Control unit 201 Processing unit 210 First control unit 211 First processing unit 220 Second control unit 221 Second processing unit 300 Memory unit 310 First memory unit 320 Second memory unit IH Human presence detection information IM Communication information IN Input information IS Non-rotation operation information MD1 First mode MD2 Second mode Q1 Arithmetic processing unit Q2 Judgment processing unit Q3 Rotation control unit Q4 Power control unit Rt Next rotation date and time T2 Standby period Tw Input detection date and time YMD Date and time

Claims

1. an image carrier; an image forming unit including a charging member that contacts the surface of the image carrier and charges the surface of the image carrier; a rotation driving unit that rotationally drives the image carrier; a date and time acquisition unit that acquires the date and time; a reception unit that receives predetermined input information that is an operation and / or state or data of a predetermined process; a control unit; a storage unit, and the control unit includes an arithmetic processing unit that acquires, from the date and time acquisition unit, the rotation stop date and time which is the date and time when the rotation of the image carrier stops, and stores, in the storage unit, as the next rotation date and time, the date and time obtained by adding a predetermined addition period to the acquired rotation stop date and time; a determination processing unit that, when the reception unit receives the predetermined input information, acquires the date and time from the date and time acquisition unit, and determines whether or not the input detection date and time which is the acquired date and time is a date and time after the next rotation date and time stored in the storage unit; When the determination processing unit determines that the input detection date and time is a date and time after the next rotation date and time, the image forming apparatus performs predetermined distance rotation control to drive the rotation driving unit to rotate the image carrier by a predetermined moving distance and then stop it.

2. The image forming apparatus according to claim 1, wherein the arithmetic processing unit calculates the next rotation date and time when the predetermined distance rotation control is performed and the image carrier stops, and updates the next rotation date and time by storing it in the storage unit.

3. The image forming apparatus according to claim 1 or claim 2, wherein the predetermined moving distance exceeds 1 times and is 5 times or less the contact width in the circumferential direction of the contact portion between the charging member and the image carrier.

4. The image forming apparatus according to claim 1 or claim 2, further comprising a control power supply that supplies power to the control unit, and an operation power supply that supplies power to the image forming unit and the rotation driving unit, wherein the control unit can selectively execute a first mode in which power is supplied from the control power supply to the control unit and power is supplied from the operation power supply to the image forming unit and the rotation driving unit, and a second mode in which power is supplied from the control power supply to the control unit and the operation power supply is turned off, and executes the first mode during a standby period which is a period shorter than the addition period from the rotation stop date and time, and executes the second mode when the reception unit does not receive the predetermined input information during the standby period. An image forming apparatus, characterized in that when the reception unit receives the input information during the execution of the second mode, the determination process unit performs determination.

5. The image forming apparatus according to claim 4, wherein the storage unit includes a first storage unit for performing a non-image forming process which is a process other than the image forming process, the control unit includes a first control unit for performing the non-image forming process and a second control unit for performing the image forming process, the first control unit includes the arithmetic processing unit, the determination processing unit, and the first storage unit, the second control unit includes the rotation control unit, the date and time acquisition unit and the reception unit are connected to the first control unit, the control power supply supplies power to both the first control unit and the second control unit when the first mode is selected, and supplies power only to the first control unit when the second mode is selected, the first control unit stores the next rotation date and time calculated by the arithmetic processing unit in the first storage unit, and when the determination processing unit determines during the second mode that the input detection date and time is a date and time after the next rotation date and time, the first mode is executed, and after the predetermined distance rotation control is performed by the second control unit, the second mode is executed again. An image forming apparatus characterized by this.

6. The image forming apparatus according to claim 4, wherein the storage unit includes a second storage unit for performing the image forming process, the control unit includes a first control unit for performing a non-image forming process other than the image forming process and a second control unit for performing the image forming process, the first control unit includes the determination processing unit, the second control unit includes the arithmetic processing unit, the second storage unit, and the rotation control unit, the date and time acquisition unit and the detection unit are connected to the first control unit, the control power supply supplies power to both the first control unit and the second control unit when the first mode is executed, and supplies power only to the first control unit when the second mode is executed, the second control unit stores the next rotation date and time calculated by the arithmetic processing unit in the second storage unit, and the first control unit executes the first mode when determining whether the input detection date and time is a date and time after the next rotation date and time by the determination processing unit, reads out the next rotation date and time from the second storage unit, and determines whether to perform the predetermined distance rotation control. An image forming apparatus characterized by this.

7. The image forming apparatus according to claim 1 or claim 2, wherein when the input information is for executing image forming processing, the control unit controls the rotation driving unit without performing the predetermined distance rotation control to rotate the image carrier and form an image in the image forming unit, and when the image carrier is stopped after the completion of the image forming processing, the arithmetic processing unit calculates the next rotation date and time, stores it in the storage unit, and updates it to the next rotation date and time. An image forming apparatus characterized by that.

8. The image forming apparatus according to claim 1 or claim 2, wherein it includes an operation reception unit that receives an input operation by an operator, the input information includes non-rotation operation information indicating a non-rotation operation in which the image carrier is not rotated among the input operations received by the operation reception unit. An image forming apparatus characterized by that.

9. The image forming apparatus according to claim 1 or claim 2, wherein it includes an input unit that receives input of communication information from the outside, the input information includes the communication information received by the input unit. An image forming apparatus characterized by that.

10. The image forming apparatus according to claim 1 or claim 2, wherein it includes a human presence detection unit that detects that a person has approached, the input information includes human presence detection information indicating that the human has been detected by the human presence detection unit. An image forming apparatus characterized by that.

Images