JP2008116679A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus constituted so that operation other than a toner supply operation may not be performed unnecessarily when it is judged that a toner cartridge replacement time comes soon or the time has come. <P>SOLUTION: When a cover to be opened/closed for the replacement of the toner cartridge is opened/closed, the image forming apparatus is controlled so that the toner supply operation may be performed prior to a warming up operation in such the situation that a near empty state or an empty state is set. Whether the near empty state or the empty state is released is checked during the toner supply operation, and whether or not the toner is supplied after the replacement of the toner cartridge is checked before the warming up operation. Based on the checking result, when it is judged that the empty state continues, the apparatus is controlled so as not to perform the warming up operation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile machine.

  As an electrophotographic image forming apparatus, for example, a photosensitive drum is used as an image carrier, the surface is charged and exposed to form an electrostatic latent image, and toner is attached to the electrostatic latent image. There is known a technique in which an image is formed by a process such that a visible image is transferred to a sheet and the transferred toner image is fixed on the sheet.

In such an image forming apparatus, the toner is consumed when the image forming process is performed. Therefore, it is necessary to replenish the toner when the remaining toner is low. When the image forming process is performed in the absence of toner, the image quality of the formed image is deteriorated, so that the image forming process is controlled (see Patent Document 1).
Japanese Patent Laid-Open No. 11-212409

  When the toner is consumed by the image forming process, the toner remaining amount detecting means detects the toner and replenishes the toner from the toner cartridge. When the toner cartridge is no longer replenished, the toner cartridge Since it is necessary to exchange, it is informed that the exchange time is near or has arrived.

  In order to accurately determine the replacement timing of the toner cartridge, it is necessary to precisely detect the remaining amount of toner, and the remaining amount is detected while the apparatus is actually operated and the toner supply operation is performed. When it is determined that the replacement time is near or has arrived, the apparatus is actually operated until the toner cartridge is replaced and the toner replenishment operation is normally performed, and the remaining amount of toner is detected repeatedly. Due to the operation of the apparatus at the time of exchanging the toner cartridge, a part such as a photosensitive drum is worn and deteriorated with use time, and the part life when used for image forming processing is shortened accordingly.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that does not perform an operation other than the toner replenishment operation more than necessary when it is determined that the replacement time of the toner cartridge is near or has arrived. It is what.

  An image forming apparatus according to the present invention includes an image carrier, a charging unit that charges the surface of the image carrier, and an exposure unit that exposes the charged surface of the image carrier to form an electrostatic latent image. Developing means for attaching a toner to the electrostatic latent image formed on the surface of the image carrier to make a visible image; transfer means for transferring the toner image formed on the image carrier to paper; A toner cartridge is replaceable in an image forming apparatus comprising: a fixing unit that fixes a transferred toner image; and a control unit that controls the rotation of the image carrier and controls each unit to form an image on a sheet. And a replenishing means for replenishing toner from the toner cartridge to the developing means, and a driving means for driving the replenishing means independently of other means.

  Another image forming apparatus according to the present invention includes an image carrier, charging means for charging the surface of the image carrier, and exposure for forming an electrostatic latent image by exposing the charged surface of the image carrier. Means, developing means for attaching a toner to the electrostatic latent image formed on the surface of the image carrier to make a visible image, transfer means for transferring the toner image formed on the image carrier to paper, An image forming apparatus comprising: a fixing unit that fixes a toner image transferred onto a sheet; and a control unit that controls the rotation of the image carrier and controls the units so as to form an image on the sheet. A replenishing unit that is replaceably mounted and replenishes toner from the toner cartridge to the developing unit, a driving unit that drives the replenishing unit independently of other units, and opens and closes when the toner cartridge is replaced. Open / close detecting means for detecting the opening / closing of the cover, and the control means determines the replacement timing of the toner cartridge, and when the opening / closing detecting means detects the opening / closing of the cover, the determining means And an operation control means for controlling the driving means so that the replenishing means performs a replenishment operation ahead of other means when it is determined that the replacement time is approaching or coming. It is characterized by. Further, the apparatus further comprises a remaining amount detecting unit that detects a remaining amount of toner replenished from the toner cartridge, and the determining unit makes a determination based on a detection signal from the remaining amount detecting unit. Further, the operation control means performs control so as not to drive other means when the determination means determines that the replacement time has arrived when the opening / closing detection means detects opening / closing of the cover. Features.

  An image forming apparatus according to the present invention includes a replenishing unit for replenishing toner from a toner cartridge to a developing unit, and a driving unit for driving the replenishing unit independently from other units. Therefore, when determining the replacement timing of the toner cartridge, it is possible to perform only the replenishment operation and prevent other means from operating, and allow other means to perform operations more than necessary. Disappear. Even when the entire apparatus is operated to perform the warm-up operation, if the replenishment operation is operated independently, the other means can be operated for a necessary time. Therefore, it is possible to suppress wear and deterioration of the parts due to an unnecessarily operation.

  In another image forming apparatus according to the present invention, when the open / close detection unit detects opening / closing of the cover, the replenishing unit controls the drive unit when the determination unit determines whether the replacement time is approaching or coming. Since it is controlled to perform the replenishment operation prior to other means, when checking whether the toner cartridge has been replaced when the opening / closing of the cover is detected, the replenishment means can be driven and controlled prior to checking. Based on the check result, other means are driven as necessary. Therefore, it is possible to control the drive at a timing that matches the time required for the operation check of other means, and depending on the check result at the time of replacement of the toner cartridge, the drive operation of the other means is stopped and unnecessary drive is performed. It is also possible not to perform the operation. In this way, the other means are not operated more than necessary, and the wear and deterioration of the parts of the other means do not proceed more than necessary.

  In addition, it is provided with a remaining amount detecting means for detecting the remaining amount of toner replenished from the toner cartridge, and the replacement time is surely determined by determining the replacement timing of the toner cartridge based on the detection signal from the remaining amount detecting means. It can be determined that the time is approaching or coming.

  Further, when the opening / closing detection means detects the opening / closing of the cover and the determination means determines that the replacement time has arrived, it is determined that the replacement time has come if the other means is not driven. Since the image forming process cannot be performed, it is not necessary to drive and check other means, and unnecessary operations can be prevented by not driving other means.

  Hereinafter, embodiments according to the present invention will be described in detail. The embodiments described below are preferable specific examples for carrying out the present invention, and thus various technical limitations are made. However, the present invention is particularly limited in the following description. Unless otherwise specified, the present invention is not limited to these forms.

  FIG. 1 is a schematic cross-sectional view of the entire image forming apparatus according to the present invention. A paper discharge tray 10 is provided in the upper part of the image forming apparatus 1, and a recording unit 2 and a paper supply unit 3 are arranged in the lower part thereof.

  In the paper feed unit 3, a paper feed cassette 11 is arranged, and a plurality of sheets of a predetermined size are stacked on the flapper 12. The flapper 12 is rotated upward in conjunction with the rotation of the arm 13 by the rotation of the arm 13 by the motor. A pickup roller 14 is disposed at the right end of the paper feed cassette 11. The flapper 12 is supported by the arm 13 so that the upper surface of the stacked paper is pressed against the pickup roller 14. When the pickup roller 14 is rotationally driven in this state, the sheets are fed one by one to the sheet conveyance path by the frictional force, and are nipped and conveyed by the feed roller 15 and the press roller 16.

  The fed paper is conveyed to the recording unit 2 by the registration roller 17 and the press roller 18. The recording unit 2 includes a developing device 19, a cleaning mechanism 20, a corona charger 21, a photosensitive drum 22, a transfer roller 23, an exposure head 24, and a fixing roller 25 for recording on the conveyed paper.

  The developing device 19 stores a two-component developer (hereinafter referred to as “developer”) and incorporates a pair of augers having spiral blades as will be described later. Is circulated in a predetermined direction. The developer conveyed in a circulating manner is supplied to the developing roller through a rotating paddle. The developing roller is composed of an internal magnet roller and a cylindrical developing sleeve disposed on the outer peripheral surface of the magnet roller, and the carrier of the developer is attracted to the surface of the developing sleeve by the magnetic force of the magnet roller to form carrier spikes. Then, the toner is attached to the formed carrier ear. In this case, since the carrier and the toner are charged with opposite polarities due to frictional charging while being conveyed, the toner is held in a stable state by the electric attraction force on the carrier ear. Further, a density detection sensor for detecting the toner density of the conveyed developer is attached in the vicinity of the developer conveyance path by the auger, and toner is replenished based on an output signal from the density detection sensor. As the concentration detection sensor, a known sensor that detects the toner concentration by measuring the magnetic permeability of the developer can be used. When a magnetic permeability sensor is used, the density of the carrier, which is a magnetic material, increases as the toner concentration decreases. Therefore, the magnetic permeability increases and the output of the sensor increases. Conversely, when the toner concentration increases, the corresponding amount increases. The density of the carrier is reduced and the output of the sensor is lowered. The toner is supplied from the toner cartridge 30 to the developing unit 19 through a toner supply mechanism described later.

  The cleaning mechanism 20 cleans the surface of the photoconductor drum 22 by scraping off foreign matters such as residual toner and paper dust attached to the surface of the photoconductor drum 22 after transfer with a cleaning blade. Foreign matter such as residual toner collected by the cleaning mechanism 20 is transported to the waste toner reservoir 31 and discharged.

  The corona charger 21 uniformly charges the surface of the photosensitive drum 22 by corona discharge from the discharge wire. An electrostatic latent image is formed on the uniformly charged photosensitive drum 22 by exposure according to the image recording signal by the exposure head 24. Then, the developing sleeve in the developing device 19 rotates and the carrier ears formed on the surface thereof approach the surface of the photosensitive drum 22 and the toner adhering to the carrier ears is transferred to the electrostatic latent image. Visualize the image. The transfer roller 23 is installed at a position facing the photosensitive drum 22 with the paper interposed therebetween, and a toner image formed on the surface of the photosensitive drum 22 is transferred to the paper when a predetermined voltage is applied. In this way, a series of processes necessary for image formation is performed, and the transferred toner image is sandwiched between the fixing roller 25 and the press roller 26 and heated and pressed to be fixed on the paper. The fixed sheet is sent to the discharge path by the feed roller 27 and the press roller 28, and is carried out to the sheet discharge tray 10 by the discharge roller 29.

  Further, a manual paper feed mechanism and a reverse conveyance mechanism are provided on the side surface of the apparatus main body. When manual paper feed is performed, the manual feed tray 32 is opened and the paper is inserted into the paper feed roller 33. . The inserted paper is conveyed to the feed roller 17 and the press roller 18 by the paper feed roller 33, and a recording operation is performed. Also, when performing reverse conveyance, the paper recorded on one side is once carried out by the discharge roller 29, then reversely rotates the discharge roller 29 and is conveyed to the reverse conveyance path, and is conveyed downward by the conveyance roller 34. . Then, the paper is transported upward along the transport path, transported again to the feed roller 17 and the press roller 18, and the recording operation is performed on the other surface to record on both surfaces of the paper.

  FIG. 2 is a schematic block diagram of the image forming apparatus shown in FIG. Around the photosensitive drum 22, a corona charger 21, an exposure head 24, a developing device 19, a transfer roller 23, a cleaning mechanism 20, and a static elimination lamp 36 are disposed, and the surface of the photosensitive drum 22 is rotated while rotating. On the other hand, after a series of process processes such as charging-exposure-development-transfer are performed, the surface is cleaned and the remaining charge is neutralized.

  In the developing unit 19, the developing roller 40 described above is disposed to face the photosensitive drum 22, and a developer storage portion is formed on the opposite side of the developing roller 40 from the photosensitive drum 22. A pair of augers 41 and 42 are arranged in the storage part. The rotation shafts of the augers 41 and 42 are linearly extended in the direction perpendicular to the paper surface, and a partition wall 43 is provided therebetween. Then, the augers 41 and 42 convey the developer in opposite directions so that the developer is circulated and conveyed around the partition wall in the reservoir.

  A density detection sensor 44 is disposed on the bottom surface corresponding to the storage portion of the developing device 19 so as to detect the toner density of the developer that is circulated and conveyed as described above. The developer conveyed in a circulating manner is supplied to the developing roller 40 by the supply paddle 45, and the developer supplied to the surface of the developing sleeve of the developing roller 40 is leveled into a uniform layer by the blade 46.

  The toner replenishing mechanism 50 delivers toner from a cartridge holding body 51 to which the toner cartridge 30 is replaceably mounted through a toner delivery path 52 to a hopper 54 having a built-in conveying spiral 53. Toner is replenished from the hopper 54 to the storage portion of the developing device 19 through the toner conveyance path 55 containing the conveyance spiral 56. The toner supply motor 61 discharges toner from the toner cartridge 30 to the hopper 54 and rotates the transport spirals 53 and 56 only when necessary by a clutch to perform toner transport operation.

  A toner remaining amount detection sensor 57 is disposed in the hopper 54. The remaining amount detection sensor 57 detects that the remaining amount of toner in the hopper 54 is less than a predetermined amount or becomes empty and outputs a detection signal. Examples of the remaining amount detection sensor include a detection sensor using a piezoelectric element. A detection sensor using a piezoelectric element is arranged near the bottom surface in the hopper, and vibration is suppressed when toner adheres around the piezoelectric element, but it vibrates when toner does not adhere. If set, the presence or absence of toner adhering to the detection sensor can be detected depending on whether or not it vibrates at the time of detection, and it can be seen that the remaining amount of toner in the hopper has decreased.

  The rotational drive of the photosensitive drum 22 and various rollers is performed by transmitting the rotation of the main motor 60 by a drive transmission mechanism such as a clutch mechanism (not shown) and is controlled by the control unit 100. Further, the developer conveying operation such as the auger of the developing device 19 is performed by transmitting the rotation drive of the main motor 60, and the toner replenishing operation of the toner cartridge 30 of the toner replenishing mechanism 50 and the toner replenishing operation by the conveying spiral or the like Is performed by transmitting the rotational drive of the toner supply motor 61, and both are controlled by the control unit 100. In addition, rotational drive can also be transmitted to the conveyance spiral 56 from the main motor 60 via a one-way gear and a clutch.

  As described above, the toner replenishment mechanism 50 is driven independently by the toner supply motor 61. However, the rotational drive of the main motor 60 is transmitted to the toner replenishment mechanism 50 via the clutch to control the clutch. The toner replenishing mechanism 50 may be driven independently.

  The voltage applied to the corona charger 21, the developing roller 40, and the transfer roller 23 is controlled by the control unit 100 controlling the developing voltage application circuit 62, the charging voltage application circuit 63, and the transfer voltage application circuit 64, respectively. Done.

  The control unit 100 includes an operation control unit 101, a replenishment control unit 102, and a determination unit 103. The operation control unit 101 performs a series of operations for performing process processing necessary for image formation, preparation operations such as warm-up, Control related to the operation to shift to the standby state.

  Further, when the cover open / close detection sensor 65 that is opened / closed when the toner cartridge is replaced detects opening / closing, the operation control unit 101 is in a near empty state and an empty state, which will be described later, and a toner supply motor. In order to check whether the near empty state or the empty state has been released by performing drive control in advance of 61, the replenishment operation is performed, and then the operation control is performed so as to perform a warm-up operation performed immediately after opening and closing the cover. If the near empty state or the empty state is not released even after the replenishment operation is performed, the operation is controlled so that the warm-up operation is not performed.

  The replenishment control unit 102 performs toner replenishment control of the toner replenishment mechanism 50 and developer transport control in the developing unit 19 based on the detection signal from the density detection sensor 44, and controls toner density in the developing unit 19. I do. Further, based on a detection signal from the remaining amount detection sensor 57, the toner supply motor 61 is rotationally driven to control replenishment of toner from the toner cartridge 30.

  The determination unit 103 determines the replacement timing of the toner cartridge 30 based on the detection signal from the remaining amount detection sensor 57. For example, the detection signal from the remaining amount detection sensor 57 is sampled to detect the presence / absence of toner in the hopper 54, and the number of samplings detected as having no toner out of a predetermined history number during the toner supply operation is predetermined. It is determined whether or not the number of times has been reached. If the number of times is equal to or greater than the predetermined number, it may be determined that the toner in the toner cartridge 30 and the hopper 54 has run out and the replacement time is approaching (near empty state).

  When a predetermined number of image forming processes are performed at the stage where the near empty state is determined, or when the toner density is lowered to a predetermined value or less by a detection signal from the density detection sensor 44, It may be determined that the replacement time has come (empty state) because the toner is also consumed.

  In this way, the determination unit 103 determines whether the toner cartridge replacement time is approaching or coming.

  Further, the determination unit 103 samples the detection signal of the remaining amount detection sensor 57 during the toner replenishing operation in the near empty state or the empty state, and the number of sampling times detected as having no toner out of a predetermined history number. Is less than the predetermined number of times, and if it is less than the predetermined number of times, the near empty state or the empty state is canceled.

  FIG. 3 is a flow relating to toner replenishment processing. When replenishing toner, first, it is checked whether or not replenishment of toner is necessary (S100). For example, when the detection signal of the remaining amount detection sensor 57 is sampled and the number of samplings detected as having no toner out of the predetermined number of histories exceeds a predetermined number, toner replenishment is required. If toner replenishment is required, it is checked whether the toner supply motor 61 is being driven (S101). If not, the toner supply motor 61 is started to be driven (S102). The toner supply operation from the toner cartridge 30 into the hopper 54 is performed by driving the toner supply motor 61. If the toner supply motor 61 is being driven in step S101, the process proceeds to step S103.

  And it is determined whether it is a near empty state (S103). During the toner replenishment operation, the detection signal of the remaining amount detection sensor 57 is sampled, and it is determined whether the number of samplings detected as having no toner out of the predetermined number of histories exceeds a predetermined number. If it is, an alarm regarding air empty is displayed (S104), a near empty flag is set, and a near empty state is set. If the predetermined number of times has not been reached, it is checked whether the toner supply motor 61 has been driven for a predetermined time (S105). If not, the process returns to step S100.

  When toner is supplied by driving the toner supply motor 61 in this way, it is determined in step S100 that toner supply is unnecessary, and the toner supply motor 61 is stopped (S106). The toner supply motor 61 is also stopped when an alarm is displayed in step S104 and when it is determined in step S105 that the toner supply motor 61 has been driven for a predetermined time.

  FIG. 4 is a processing flow when waiting in a near empty state. It is checked whether a warm-up operation has been requested (S200). If not, the presence / absence of a recording signal is checked (S201). If there is a recording signal, it is checked whether the number of recordings from the near empty state has reached a predetermined number or more (S202). If the recording number has not reached the predetermined number, the toner density is determined based on the detection output of the density detection sensor 44. Is checked to see if it is less than or equal to a predetermined value (S203), and if it exceeds the predetermined value, it stands by in a near empty state.

  If the number is equal to or greater than the predetermined number in step S202 or less than the predetermined value in step S203, an empty alarm is displayed as the consumption of the toner in the developing device 19 has progressed and the remaining amount has decreased (S204). Set the flag to empty.

  If a warm-up operation is requested in step S200, the toner supply motor starts to be driven (S205), and a replenishment operation from the toner cartridge into the hopper is performed. Then, the detection signal of the remaining amount detection sensor 57 during the toner replenishing operation is sampled, and it is determined whether the number of samplings detected as having no toner out of the predetermined number of history is equal to or less than a predetermined number, and the empty state is released. It is determined whether it has been performed (S206). If the empty state has not been released, the toner supply motor is stopped (S207), and the system waits in the near empty state. If it is determined in step S206 that the empty state has been released, the alarm display is released (S208), the near empty state is released, the toner supply motor is stopped (S209), and the normal standby state is set.

  FIG. 5 is a flow relating to toner cartridge replacement processing. First, it is checked whether or not a cover that is opened and closed when the toner cartridge is replaced is opened (S300). When checking, the detection signal from the cover open / close detection sensor 65 is checked. If it is detected that the cover has been opened / closed, it is checked whether or not the empty state is set (S301). If the empty state is set, the toner supply motor is driven to start the replenishing operation (S301). S302). Then, it is checked whether the empty state has been released based on the detection signal of the remaining amount detection sensor during the replenishment operation (S303), and if it has not been released, it is checked whether a predetermined time has passed (S304). If the predetermined time has not elapsed, the process returns to step S303 to repeatedly check whether the empty state has been released. If it is determined in step S304 that the predetermined time has elapsed, the toner replenishment operation is stopped (S305), and the process returns to the standby state without performing the warm-up operation.

  If it is determined in step S303 that the empty state has been canceled, the empty alarm display is canceled (S306), the toner replenishment operation is stopped (S307), and a warm-up operation is performed (S315).

  If it is determined in step S301 that the empty state is not set, it is checked whether the near empty state is set (S308). If the near empty state is set, the toner supply motor is driven. The replenishment operation is started (S309). Then, it is checked whether the empty state has been released based on the detection signal of the remaining amount detection sensor during the replenishment operation (S310), and if it has not been released, it is checked whether a predetermined time has passed (S311). If the predetermined time has not elapsed, the process returns to step S310 to repeatedly check whether the empty state has been released. If it is determined in step S311 that the predetermined time has elapsed, the toner replenishing operation is stopped (S312), and the process proceeds to a warm-up operation (S315).

  If it is determined in step S310 that the empty state has been released, the near empty alarm display is canceled (S313), the toner replenishment operation is stopped (S314), and a warm-up operation is performed (S315).

  If it is determined in step S308 that the near empty state is not set, the process proceeds to the warm-up operation as it is (S315).

  In the above processing, when the near empty state or the empty state is set when the cover that is opened and closed when the toner cartridge is replaced is opened and closed, the toner supply operation is performed prior to the warm-up operation. Thus, it can be checked before the warm-up operation whether the toner cartridge has been replaced and the toner has been replenished. Therefore, the warm-up operation itself may be controlled in the same manner as in the past, and is not extended for checking the replacement of the toner cartridge. If it is determined in the toner cartridge replacement check that the toner cartridge is still in an empty state, the image forming process cannot be performed, so that the warm-up operation itself is unnecessary. Thus, the warming-up operation is not performed more than necessary when the toner cartridge replacement check is performed.

1 is a schematic sectional view of an entire image forming apparatus according to an embodiment of the present invention. It is a schematic block diagram regarding the embodiment concerning the present invention. 10 is a flow relating to toner supply processing. It is a processing flow in the case of waiting in a near empty state. 10 is a flow relating to toner cartridge replacement processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Recording part 3 Paper feeding part

Claims (4)

  An image carrier, charging means for charging the surface of the image carrier, exposure means for exposing the charged surface of the image carrier to form an electrostatic latent image, and formed on the surface of the image carrier. A developing means for making a visible image by attaching toner to the electrostatic latent image, a transfer means for transferring the toner image formed on the image carrier to a sheet, and a fixing for fixing the toner image transferred to the sheet In the image forming apparatus, the toner cartridge is replaceably mounted and the toner cartridge is removed from the toner cartridge. The image forming apparatus includes: a control unit configured to control the rotation of the image carrier and control the units to form an image on a sheet; An image forming apparatus comprising: a replenishing unit that replenishes toner to the developing unit; and a driving unit that drives the replenishing unit independently of other units.   An image carrier, charging means for charging the surface of the image carrier, exposure means for exposing the charged surface of the image carrier to form an electrostatic latent image, and formed on the surface of the image carrier. A developing means for making a visible image by attaching toner to the electrostatic latent image, a transfer means for transferring the toner image formed on the image carrier to a sheet, and a fixing for fixing the toner image transferred to the sheet In the image forming apparatus, the toner cartridge is replaceably mounted and the toner cartridge is removed from the toner cartridge. The image forming apparatus includes: a control unit configured to control the rotation of the image carrier and control the units to form an image on a sheet; Supply means for supplying toner to the developing means, drive means for driving the supply means independently of other means, and opening / closing for detecting opening / closing of a cover that is opened and closed when the toner cartridge is replaced And determining means for determining when to replace the toner cartridge; and when the opening / closing detecting means detects opening / closing of the cover, the determining means determines whether the replacement time is approaching or coming. And an operation control means for controlling the drive means so that the replenishing means performs a replenishment operation ahead of other means.   3. The apparatus according to claim 2, further comprising: a remaining amount detecting unit configured to detect a remaining amount of toner replenished from the toner cartridge, wherein the determining unit performs determination based on a detection signal from the remaining amount detecting unit. The image forming apparatus described.   The operation control means performs control so as not to drive other means when the determination means determines that the replacement time has arrived when the opening / closing detection means detects opening / closing of the cover. The image forming apparatus according to claim 2 or 3.

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