JP2005141205A - Image forming apparatus and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase convenience in the attaching/detaching operation of a processing unit by a user. <P>SOLUTION: When the outside cover of an apparatus housing is opened and an exchange indication button is depressed by the user, developing device exchanging operation is performed. When the outside cover is closed again (step S402) after the attachment/detachment of a developing device becomes possible by pre-exchange processing (step S401), succeeding operation is made to vary according as whether or not the developing device is exchanged at that time (step S403). When the developing device is exchanged, post-exchange processing is performed immediately (step S404). Meanwhile, when the developing device is not exchanged, time counting is started (step S405) and the post-exchange processing is performed after prescribed waiting time elapses (step S406). Since the attachable/detachable state of the developing device is maintained when the user opens the outside cover during the waiting time, work can be performed immediately. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus having a process unit that can be attached to and detached from an apparatus main body, and a control method therefor.

  In image forming apparatuses such as printers, copiers, and facsimile machines, a process unit is generally configured to be detachable from the apparatus main body for exchanging consumables. As such a device, in order to manage the usage status of each unit and appropriately replace the consumables, the device is configured to allow the user to attach / detach the unit only when the device can check whether the unit is attached or detached. There is. For example, in the image forming apparatus described in Patent Document 1, the developing unit can be taken out when the developing rotary configured to be mounted with the developing unit is rotationally positioned at a predetermined take-out position, while at other positions. When it is positioned, it cannot be taken out. Positioning to the development rotary to the take-out exclusive position is executed based on an exchange instruction from the user. Since the positioning of the developing rotary is performed under the control of the controller, it is possible to confirm on the apparatus side whether or not the unit is attached and detached by the user.

  In addition, in this type of image forming apparatus, in order to improve maintainability inside the apparatus, it is common to provide an openable / closable cover on a part of the apparatus casing.

JP 2002-333756 A (FIG. 3)

  In the above-described image forming apparatus of Patent Document 1, after the user completes the attachment / detachment operation, the apparatus returns to a normal state, that is, a state in which the developer cannot be attached / detached. Specifically, the developing unit cannot be attached or detached by moving the developing rotary to a home position provided separately from the take-out dedicated position. Note that the end of the operation by the user can be estimated, for example, when the cover is closed.

  However, a cover may be closed due to a user's operation error without correctly attaching and detaching a process unit such as a developing device. In such a case, even if the user opens the cover again and tries to continue the operation, the apparatus has returned to a state in which the unit cannot be attached and detached. For this reason, the user has to start over from the beginning and has to wait until the apparatus is ready to be attached and detached again.

  The present invention has been made in view of the above problems, and an object of the present invention is to improve the convenience of a process unit attaching / detaching operation by a user in an image forming apparatus having a process unit detachable from an apparatus main body and a control method thereof. To do.

  The present invention includes a process unit configured to be detachable with respect to the apparatus main body, switching means for switching the apparatus between a detachable state and a non-detachable state of the process unit, and an openable / closable to the apparatus main body In order to achieve the above object, an image forming apparatus comprising the above-described cover member that restricts a user to attach / detach the process unit in the closed state and a control method thereof, the apparatus is in a state in which the process unit can be attached / detached. When the cover member is closed at the time, the attachment / detachment prohibiting process for controlling the switching means to switch the apparatus to the non-detachable state is executed, and the cover member is closed. If the process unit has not been attached / detached before, the process unit is attached / detached. Than if had, is characterized in that to increase the wait time from when the cover member is closed until the start of execution of the detachable inhibition process.

  In the present specification, “attaching / detaching” a process unit means an operation of taking out the process unit from the apparatus main body and / or attaching the process unit to the apparatus main body by the user.

  In the invention configured as described above, when the cover member is closed by the user, the attachment / detachment prohibiting process is executed, and the apparatus is switched to a state in which the process unit cannot be attached / detached. However, when the cover member is closed without attaching / detaching the process unit, the waiting time for starting the attachment / detachment prohibition process is made longer than when the cover member is closed after the attaching / detaching operation. The reason for this is as follows.

  If the cover member is closed after the process unit has been attached / detached, the user can assume that the attachment / detachment operation has been completed, so the attachment / detachment prohibition process is executed in a relatively short time after the cover is closed. May be. On the other hand, when the cover member is closed without attaching / detaching the unit, there may be a case where a user's operation error occurs. However, if the cover member is closed and the apparatus shifts to a state in which the unit cannot be attached / detached within a short time, the user cannot open the cover member again and immediately move to the attaching / detaching operation, which is inconvenient.

  Therefore, in such a case, a waiting time is provided before the attachment / detachment prohibition process is started. By doing so, if the user opens the cover member again during this waiting time, the apparatus is maintained in a state where the process unit can be attached and detached, so that the attaching / detaching operation can be continued as it is. Thus, according to the present invention, it is possible to improve the convenience of the process unit attaching / detaching operation by the user.

  Note that, in the image forming apparatus configured as described above, it is preferable that execution of the attachment / detachment prohibition process is stopped when the cover member is opened during the start waiting time. By doing so, it is possible to prevent the apparatus from shifting to a state in which the process unit is not detachable even when the cover member is opened again.

  The apparatus may further comprise detection means for detecting a change in the state of the apparatus relating to whether or not the process unit has been attached or detached, and whether or not the process unit is attached or detached is determined based on a detection result of the detection means. Good. By doing so, it can be reliably determined whether or not the process unit has been attached or detached.

  The process unit is configured to be attachable / detachable through an attachment / detachment opening provided in the apparatus main body, and is provided to be openable / closable with respect to the attachment / detachment opening to restrict attachment / detachment of the process unit in the closed state. The detection unit is further configured to detect opening / closing of the restriction member, and the detection unit detects that the control member is closed again after being opened. Accordingly, it may be determined that the process unit has been attached or detached. That is, a series of user operations in which the process unit attachment / detachment restriction by the restriction member is once released and then restricted again can be regarded as the attachment / detachment work to the process unit. With such a configuration, it is possible to determine whether or not the apparatus is attached / detached only on the apparatus main body side, and a structure for detecting attachment / detachment on the process unit side is unnecessary.

  Further, when the time from when the restricting member is opened to when it is closed again is less than a predetermined time, it may be determined that the process unit is not attached or detached. Since a certain amount of time is required for attaching / detaching the process unit, it may be determined that the operation has not been performed if the time during which the restriction member is opened is shorter than the time required for the attaching / detaching operation. The predetermined time is preferably shorter than the time required for attaching / detaching work by a skilled worker, and can be, for example, about several seconds.

  The same applies to the case where the detection means is configured to detect opening and closing of the cover member, and when the time from when the cover member is opened until it is closed again is less than a predetermined time, It can be determined that the process unit is not attached or detached. Such a configuration can be applied regardless of whether the apparatus includes the above-described regulating member.

  In addition, the process unit may include a storage unit that stores information about the unit, and in the attachment / detachment prohibition process performed after the process unit is attached / detached, an operation of reading the information from the storage unit may be performed. . As a result, information on the process unit is grasped on the apparatus main body side, and it becomes possible to appropriately manage the life and usage status thereof.

  Further, the apparatus further comprises an instruction input means for accepting a process unit attachment / detachment instruction from a user, and when the instruction input is made to the instruction input means, the apparatus is made detachable by the switching means. It may be. By doing so, the apparatus can be shifted to a state in which the process unit can be attached / detached in accordance with a user's intention to attach / detach the process unit. In addition, since the process unit cannot be attached or detached unless an operation based on the user's intention is received, an error such as a mistake in the process unit to be operated is unlikely to occur.

  Examples of the process unit referred to in the present invention include a developing device that can be attached to and detached from a developing rotary provided in the apparatus main body. A driving means for rotating the developing rotary can function as the switching means. In other words, the drive means can selectively attach and detach the developing device by selectively positioning the developing rotary at a predetermined attaching or detaching position determined corresponding to the developing device or other position, and the developing device. It is possible to switch between the state in which the attachment / detachment is impossible.

<First Embodiment>
FIG. 1 is a diagram showing a first embodiment of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus of FIG. This apparatus 1 forms a full color image by superposing four color toners (developers) of yellow (Y), cyan (C), magenta (M), and black (K), or black (K) toner. This is an image forming apparatus that forms a monochrome image using only the image forming apparatus. In the image forming apparatus 1, when an image signal is given to the main controller 11 from an external device such as a host computer, the engine controller 10 controls each part of the engine unit EG in accordance with a command from the main controller 11 to obtain a predetermined image. The forming operation is executed, and an image corresponding to the image signal is formed on the sheet S.

  In the engine unit EG, the photosensitive member 22 is provided to be rotatable in the arrow direction D1 in FIG. A charging unit 23, a rotary developing unit 4 and a cleaning unit 25 are arranged around the photosensitive member 22 along the rotation direction D1. The charging unit 23 is applied with a predetermined charging bias, and uniformly charges the outer peripheral surface of the photoconductor 22 to a predetermined surface potential. The cleaning unit 25 removes the toner remaining on the surface of the photosensitive member 22 after the primary transfer, and collects it in a waste toner tank provided inside. The photosensitive member 22, the charging unit 23, and the cleaning unit 25 integrally constitute the photosensitive member cartridge 2, and this photosensitive member cartridge 2 is detachably attached to the main body of the apparatus 1 as a whole.

  Then, the light beam L is irradiated from the exposure unit 6 toward the outer peripheral surface of the photosensitive member 22 charged by the charging unit 23. The exposure unit 6 exposes the light beam L onto the photosensitive member 22 in accordance with an image signal given from an external device, and forms an electrostatic latent image corresponding to the image signal.

  The electrostatic latent image thus formed is developed with toner by the developing unit 4. The developing unit 4 is configured as a support frame 40 that is rotatably provided around a rotation axis that is orthogonal to the paper surface of FIG. 1 and a cartridge that is detachable from the support frame 40, and for yellow that contains toner of each color. A developing unit 4Y, a developing unit 4C for cyan, a developing unit 4M for magenta, a developing unit 4K for black, and a rotary driving unit (described later) for rotating them integrally are provided. The developing unit 4 is controlled by the engine controller 10. Based on the control command from the engine controller 10, the developing unit 4 is driven to rotate, and the developing units 4Y, 4C, 4M, and 4K are selectively brought into contact with the photoreceptor 22 or have a predetermined gap. When positioned at a predetermined development position opposed to each other, toner is applied to the surface of the photosensitive member 22 from a developing roller 44 provided in the developing unit and carrying toner of a selected color. As a result, the electrostatic latent image on the photosensitive member 22 is visualized with the selected toner color.

  The toner image developed by the developing unit 4 as described above is primarily transferred onto the intermediate transfer belt 71 of the transfer unit 7 in the primary transfer region TR1. The transfer unit 7 includes an intermediate transfer belt 71 that is stretched over a plurality of rollers 72 to 75, and a drive unit that rotates the roller 73 to rotate the intermediate transfer belt 71 in a predetermined rotation direction D2. . When a color image is transferred to the sheet S, each color toner image formed on the photosensitive member 22 is superimposed on the intermediate transfer belt 71 to form a color image and taken out from the cassette 8 one by one. The color image is secondarily transferred onto the sheet S conveyed to the secondary transfer region TR2 along the conveyance path F.

  At this time, in order to correctly transfer the image on the intermediate transfer belt 71 to a predetermined position on the sheet S, the timing of feeding the sheet S to the secondary transfer region TR2 is managed. Specifically, a gate roller 81 is provided on the transport path F on the front side of the secondary transfer region TR2, and the gate roller 81 rotates in accordance with the timing of the circumferential movement of the intermediate transfer belt 71. S is sent to the secondary transfer region TR2 at a predetermined timing.

  Further, the sheet S on which the color image is thus formed is conveyed to the discharge tray portion 89 provided on the upper surface portion of the apparatus main body via the fixing unit 9, the pre-discharge roller 82 and the discharge roller 83. Further, when images are formed on both sides of the sheet S, when the rear end portion of the sheet S on which the image is formed on one side as described above is conveyed to the reversal position PR behind the pre-discharge roller 82. The rotation direction of the discharge roller 83 is reversed, whereby the sheet S is conveyed in the direction of the arrow D3 along the reverse conveyance path FR. Then, the sheet is again placed on the transport path F before the gate roller 81. At this time, the surface of the sheet S to which the image is transferred by contacting the intermediate transfer belt 71 in the secondary transfer region TR2 is first transferred. It is the opposite surface. In this way, images can be formed on both sides of the sheet S.

  As shown in FIG. 2, each of the developing devices 4Y, 4C, 4M, and 4K is provided with memories 91 to 94 for storing data relating to the manufacturing lot and usage history of the developing devices and the remaining amount of the built-in toner. ing. Further, connectors 49Y, 49C, 49M, and 49K are provided in the developing devices 4Y, 4C, 4M, and 4K, respectively. If necessary, these are selectively connected to a connector 109 provided on the main body side, and data is transmitted / received between the CPU 101 and each of the memories 91 to 94 via the interface 105 to relate to the developing device. It manages various information such as consumables management. In this embodiment, the main body side connector 109 and each developing device side connector 49K and the like are mechanically fitted to each other to exchange data. However, for example, electromagnetic means such as wireless communication is used. Data transmission / reception may be performed without contact.

  In FIG. 2, reference numeral 113 denotes an image memory provided in the main controller 11 for storing an image given from an external device such as a host computer via the interface 112, and reference numeral 117 denotes an operation result in the CPU 111. It is a RAM that temporarily stores other data. Reference numeral 106 is a ROM for storing a calculation program executed by the CPU 101, control data for controlling the engine unit EG, and the like. Reference numeral 107 is a RAM for temporarily storing calculation results in the CPU 101 and other data. is there. Further, reference numeral 108 denotes a RAM that stores information on the usage status of each part of the apparatus including the developing device 4Y. As the RAM 108 and the memories 91 to 94, it is preferable to use a nonvolatile memory that is writable and retains information even in a non-energized state. As such an element, for example, a flash memory or a ferroelectric memory is used. be able to.

  In addition, limit switches 122 and 132 for detecting the opening and closing of a cover provided in the apparatus housing are connected to the CPU 101 of the apparatus 1. These will be described in detail later.

  3 is an external perspective view of the image forming apparatus of FIG. As described above, in the image forming apparatus 1, each developing device 4Y and the like are detachable from the support frame 40, and the photosensitive cartridge 2 is detachable from the apparatus main body. As shown in FIG. 3, an openable / closable external cover 120 is provided on the side surface of the apparatus main body 1. When the user opens the external cover 120, the image is exposed through the photosensitive member opening 125 provided in the apparatus main body. The side part of the body cartridge 2 is exposed. Then, the lock lever 126 for fixing the photoconductor cartridge 2 is rotated in the arrow direction D4 to release the lock, and the photoconductor 2 can be pulled out along the (−y) axis direction of FIG. . Further, by inserting the photoconductor cartridge 2 in the y-axis direction of FIG. 3 through the photoconductor opening 125, a new photoconductor cartridge 2 can be mounted. Then, the photosensitive cartridge 2 is fixed by the lock lever 125. When the photoconductor cartridge 2 is thus mounted, the photoconductor opening 125 is substantially blocked by the side surface of the photoconductor cartridge 2.

  The apparatus main body is provided with a developing device opening 135 for attaching and detaching the developing device cartridge. An openable / closable inner cover 130 is provided so as to cover the developing device opening 135. The inner cover 130 is provided inside the outer cover 120. That is, since the outer cover 120 is formed so as to cover the developer opening 135, the inner cover 130 cannot be opened when the outer cover 120 is closed. Conversely, the outer cover 120 cannot be closed unless the inner cover 130 is closed. When the user opens the inner cover 130, if the developing unit 4 is stopped at a predetermined attachment / detachment position, one of the attached developing devices can be taken out through the developing device opening 135. . In addition, one developing device can be mounted through the developing device opening 135.

  The outer cover 120 is provided with a protrusion 121a, and a hole 121b is provided at a position on the main body side corresponding to the protrusion 121a. Further, a limit switch 122 described later is attached to the bottom of the hole 121b. When the outer cover 120 is closed, the protrusion 121a is inserted into a hole 121b provided on the main body side, and the contact is closed by pressing a limit switch 122 provided at the bottom of the hole 121b. .

  A similar mechanism is also provided in the inner cover 130. That is, the protrusion 131a is provided on the inner cover 130, and the hole 131b is provided at a position corresponding to the main body side. When the inner cover 130 is closed, the protrusion 131a is inserted into the hole 131b, and the contact is closed by pressing a limit switch 132 (described later) provided at the bottom of the hole 131b.

  Further, a limit switch (not shown) is also provided behind the photoconductor opening 125, and the contact is closed when the photoconductor cartridge is mounted on the apparatus main body. This limit switch is preferably installed so that the contact is closed when the photosensitive cartridge 2 is properly mounted on the apparatus main body, while the contact is not closed when the photosensitive cartridge 2 is incompletely mounted. This is because it is necessary to detect that the mounting unit is securely mounted so that the developing unit 4 is not rotated in an incomplete mounting state and the apparatus is not damaged.

  As described above, in the image forming apparatus 1, for each of the external cover 120 and the internal cover 130, the open / close state of the cover can be known from the contact state of each limit switch, and the photosensitive cartridge 2 is mounted. It is possible to know whether or not. The image forming operation described above is executed only when the outer cover 130 and the inner cover 130 are closed and the photosensitive cartridge 2 is mounted.

  FIG. 4 is a diagram showing a power feeding path of the image forming apparatus. The image forming apparatus 1 is configured to operate with a commercial AC power source. That is, the apparatus 1 includes DC power supplies 205 and 224 that convert the AC power supply voltage into DC voltages of 5V and 24V, respectively. The output voltage of the 5V DC power supply 205 is supplied to a control circuit such as the engine controller 10. The limit switches 122 and 132 are also supplied with a 5V DC voltage via the pull-up resistors 123 and 133, respectively, and the terminal voltages thereof are input to the CPU 101, respectively. That is, the CPU 101 detects the open / closed states of the outer cover 120 and the inner cover 130 by detecting the terminal voltages of these limit switches.

  On the other hand, the output voltage of the 24V DC power supply 224 is supplied to a power system load such as a motor that drives each part of the movable part of the apparatus 1. Such loads include a motor 48M for rotating the developing unit 4 and its driver 48D (rotary drive unit), a motor 28M for rotating the photosensitive member 22 and its driver 28D, and a roller 75 of the transfer unit 7. And a motor 78M for rotating the intermediate transfer belt 71 and a driver 78D thereof.

  The CPU 101 can output three types of enable control signals EN1, EN2, and EN3. These control signals EN1 to EN3 are control signals for switching the unit to which the signal is input to the operating state / non-operating state. For example, when the control signal EN1 input to the 24V DC power supply 224 is at the H level, the power supply 224 operates, while when the control signal EN1 is at the L level, the power supply 224 is stopped. Similarly, the driver 48D is controlled by the control signal EN2, and the drivers 28D, 78D and other units operating with the 24V power supply are controlled by the control signal EN3. In this way, the CPU 101 can shift each unit to a non-operating state as necessary, so that only the necessary units are in an operating state, thereby prohibiting unnecessary operation of the device or consuming the entire device. Electric power can be reduced.

  Next, the attaching / detaching operation of the developing device in the image forming apparatus will be described in more detail with reference to FIGS. FIG. 5 is a schematic diagram showing the stop position of the developer cartridge. FIG. 6 is a diagram showing a developing device operation unit of the image forming apparatus. Here, a description will be given of an operation for replacing a developing device by a user, that is, an operation in which a developing device attached to the apparatus is taken out and another developing device is newly attached. The operation is basically the same.

  In this image forming apparatus, the developing unit 4 is positioned and fixed at the three types of positions shown in FIG. 5 by the engine controller 10 and a rotary lock mechanism (not shown). The three types of positions are: (a) home position; (b) development position; (c) attachment / detachment position. Among them, (a) the home position is a position that is positioned when the apparatus 1 is in a standby state in which no image forming operation is performed, and is provided in each developing device 4Y and the like as shown in FIG. Each of the developing rollers 44 is in a state of being separated from the photosensitive member 22, and no developing device can be taken out through the developing device opening 135 provided in the apparatus main body.

  Further, (b) the development position is a position that is positioned when the electrostatic latent image on the photosensitive member 22 is visualized with a selected toner color. As shown in FIG. 5B, a developing roller 44 provided in one developing device (yellow developing device 4Y in the example of FIG. 5) is arranged to face the photosensitive member 22 and is applied with a predetermined developing bias. As a result, the electrostatic latent image is visualized with toner. Even at this developing position, any developing device cannot be taken out through the developing device opening 135. If the external cover 120 is opened during the image forming operation, the image forming operation is immediately stopped, and the developing unit 4 stops after moving to the home position.

  At this development position, as shown in FIG. 5B, a connector provided in one of the development units attached to the development unit 4 (in this figure, a connector 49C provided in the cyan development unit 4C), The main body side connector 109 is disposed opposite to each other. In this state, when the main body side connector 109 moves toward the developing device, both the connectors are fitted, and the CPU 101 can access the memory 92 on the developing device side. That is, in this embodiment, prior to communication between the CPU 91 and the memory 91 provided in each developing device 4Y, etc., a step is required in which the developing unit 4 is rotationally driven and positioned and fixed at the developing position.

  Further, access from the CPU 101 to each memory is limited to the minimum necessary number in order to suppress wear of the connector 109 and the like and extend the life of the apparatus. Specifically: When a new developing device is attached to the developing unit 4, information stored in the memory of the developing device is read and the information is stored in the RAM 108 of the engine controller 10. Then, the information is updated and stored as needed according to the usage status of the apparatus, and when the developing device is taken out, the latest information stored in the RAM 108 is written in the memory of the developing device before the taking out. By doing so, it is only necessary to access the memory of the developing device only when the developing device is mounted and taken out.

  Further, (c) the attach / detach position is a position that can be taken only when the attach / detach operation of the developing device is performed. When the developing unit 4 is positioned at this attaching / detaching position, as shown in FIG. 5C, one developing unit appears in the developing device opening 135 and can be taken out through the opening 135. FIG. 5C shows a state where the yellow developing device 4Y appears in the developing device opening 135. FIG. In addition, a developing device can be newly attached to the support frame 40 to which the developing device is not attached. In this attaching / detaching position, the developing roller 44 provided in any of the developing devices is placed at a position sufficiently separated from the photosensitive member 22. In this way, it is possible to take out only one developing device that appears in the developing device opening 135 when the developing unit 4 is positioned at the attachment / detachment position. Therefore, the user does not inadvertently attach and detach the developing device and damage the apparatus.

  In the image forming apparatus 1, the development position and the attachment / detachment position described above are set for each of the four developing devices 4Y, 4C, 4M, and 4K. Therefore, the stop position of the development unit 4 is one home position. There are nine places including convenience.

  As described above, in the image forming apparatus 1, the developing unit 4 is positioned at the home position in the standby state where the image forming operation is not performed. Further, when the external cover 120 is opened during the image forming operation, the developing unit 4 moves to the home position and stops. Therefore, even if the user opens the outer cover 120 and then opens the inner cover 130 to expose the developer opening 135, the developer cannot be immediately taken out.

  In the image forming apparatus 1, when the user operates the developing device operation unit 150 shown in FIG. 6, the rotary developing unit 4 is moved to the attaching / detaching position, so that the developing device can be attached / detached for the first time. Specifically, when the user presses a button corresponding to the toner color desired to be replaced among the replacement instruction buttons 151M, 151K, 151C, and 151Y provided on the developing device operation unit 150, the motor controlled by the engine controller 10 is controlled. The developing unit 4 is rotationally driven by a predetermined amount by 48M and positioned at the attaching / detaching position, and a developing device corresponding to the selected toner color appears in the developing device opening 135. Then, the user opens the internal cover 130 with the developing unit 4 positioned at the attaching / detaching position as described above, and attaches / detaches the developing device 4Y and the like through the developing device opening 135.

  In the apparatus 1 configured as described above, the CPU 101 controls each part of the apparatus, so that the following four operation modes: a normal operation mode in which an image forming operation can be executed; An exchange operation mode in which the attachment / detachment work is possible; an all-stop mode for prohibiting the image formation operation and the attachment / detachment work of the developer; and a power saving mode in which the operation of the 24V DC power supply 224 is stopped can be selectively executed. .

  FIG. 7 is a diagram showing the correspondence between each operation mode and the set value of each control signal. The CPU 101 sets the control signals EN1 to EN3 to the combinations shown in FIG. 7 according to the operation mode of the device to be executed. Thereby, in each operation mode, a necessary unit becomes operable, and unnecessary unit operations are stopped. In the power saving mode among the operation modes, the operation of the 24V power supply itself for operating each unit is stopped, and the control signals EN2 and EN3 at this time are arbitrary.

  FIG. 8 is a flowchart for explaining the transition of the operation mode in this apparatus. 9 and 10 are flowcharts showing the sleep process and the exchange operation, respectively. Further, FIGS. 11 and 12 are flowcharts showing the pre-replacement process and the post-replacement process, respectively.

  In this apparatus 1, when an image signal is given from an external apparatus, an image forming operation for forming an image corresponding to the image signal is executed (normal operation mode), but the period during which the image signal is not given extends over a predetermined time. When the operation is continued, in order to save the power consumption of the apparatus, the normal operation mode is shifted to the power saving mode. FIG. 8 shows a processing operation of the CPU 101 when a new image signal is not given after a series of image forming operations is completed.

  When the image forming operation is finished and no new image signal is given, the CPU 101 starts counting by an internal timer as shown in FIG. 8 (step S101). Then, it is determined whether or not the timed result has reached a predetermined time (for example, 10 minutes) set in advance (step S102). When the predetermined time is reached, a sleep process is performed to shift the device to the power saving mode (step S102). S103) is executed. The sleep process will be described later.

  On the other hand, when the measured time is less than the predetermined time in step S102 (for example, immediately after the end of the image forming operation), the open / close state of the external cover 120 is determined based on the terminal voltage of the limit switch 122 (step S105). ). At this time, if the external cover 120 is closed, the process returns to step S102. Therefore, the process of steps S102 and S105 is continued while keeping the time until the time measurement result reaches a predetermined time or the external cover 120 is opened. The loop will be repeated. If the external cover 120 is opened during this time, the apparatus shifts to the replacement operation mode (step S106). That is, the CPU 101 changes the control signal EN3 to the L level, whereby the operation of each part of the apparatus excluding the control circuit, the 24V power source 224 and the developing unit 4 is stopped.

  In the replacement operation mode, the developing unit 4 can be rotated, so that the developing device can be attached and detached, while the other units are stopped. Therefore, the power consumption can be kept lower than in the normal operation mode. Is possible. In particular, by stopping energization of the heater (not shown) of the fixing unit 9 that consumes a large amount of power in the normal operation mode, a more significant power consumption reduction effect can be obtained. Since the image formation is not performed in the exchange operation mode, in addition to the above, the operations of the exposure unit 6 and each part for sheet conveyance may be stopped. Thereby, power consumption can be further reduced.

  However, in this exchange operation mode, since the 24V power source 224 and the developing unit 4 are in the operating state, the power consumption by them is still continued. Even if there is no problem when the unit is subsequently attached / detached, in this state, that is, when the device is left with the external cover 120 opened, such power consumption is ignored. It may become impossible. Therefore, in order to suppress the waste of electric power in such a case, when the external cover 120 is opened, the timing is reset once and restarted (step S107), and when it is left as it is until a predetermined time elapses ( Step S108) and a sleep process (step S103) are executed to shift to the power saving mode. In this embodiment, the “predetermined time” from the start of timing to the sleep process may be the same value in step S102 and step S108, or may be different from each other.

  In the sleep process, as shown in FIG. 9, first, the apparatus shifts to a power saving mode (step S201). In other words, the CPU 101 stops the operation of the power supply 224 by changing the enable control signal EN1 applied to the 24V DC power supply 224 from the H level to the L level. Thereby, the operation of each part of the apparatus excluding the control circuit is stopped, and the power consumption of these parts and the power source 224 is also minimized.

  In this state, the CPU 101 determines whether or not the external cover 120 is open based on the terminal voltage of the limit switch 122 (step S202). If the external cover 120 is open, step S202 is repeated until the cover is closed. On the other hand, if the external cover 120 is closed, the process proceeds to the next step S203, and waits until the cover is opened. Then, when the cover is opened, the process returns to the main process of FIG. 8 and step S104 is executed to shift from the power saving mode to the normal operation mode. That is, the power source 224 is restarted and each part of the apparatus is shifted to a state where image formation is possible.

  With this series of processing, the state change of the apparatus during execution of the power saving mode is as follows. First, when the apparatus shifts to the power saving mode with the external cover 120 closed, the power saving mode is maintained while the cover is closed (loop in step S203), while the power saving mode is maintained when the cover 120 is opened. Leave the mode and enter the normal operation mode. Further, in the case of shifting to the power saving mode with the external cover 120 opened, the cover is temporarily closed (loop in step S202) and then the cover is opened again (loop in step S203). ), Shift to normal operation mode. The reason for this will be described later.

  Returning to step S108 in FIG. 8, processing when a predetermined time has not elapsed since the transition to the replacement operation mode will be described. In this case, it is further determined whether or not the inner cover 130 is open based on the terminal voltage of the limit switch 132 (step S109). When the inner cover 130 is open, the device executes the full stop mode. At this time, the developer cannot be attached or detached. This is because the developing unit 4 is not in the attach / detach position.

  This all-stop mode is intended to prohibit the rotation of the developing unit 4 when the inner cover 130 is opened, and is different from the power saving mode that aims to reduce the power consumption of the apparatus. Here, the enable control signal given to the developing unit 4 by the CPU 101 is set to the L level, so that the developing unit 4 is stopped. However, the mechanical lock mechanism that operates when the inner cover 130 is opened is used to control the developing unit 4. You may make it regulate rotation. If the operation of the power source 224 is stopped when the inner cover 130 is opened, as in the power saving mode, the development when the inner cover 130 is closed takes time to restart the power source 224. The start of the unit 4 is delayed and it takes time for the work.

  Further, even when the device is in the all-stop mode in this way, if the device is left in that state for a predetermined time, the device performs the sleep process described above and shifts to the power saving mode (step S111).

  On the other hand, if the inner cover 130 is closed in step S109, it is subsequently determined whether or not the replacement instruction button has been pressed (step S112). Specifically, when one of the buttons (FIG. 6) of the developing device operation unit 150 is pressed by the user, the replacement instruction flag corresponding to that button is set. Determine if the button was pressed.

  If it is determined that the replacement instruction button has not been pressed, the process proceeds to step S114. If the external cover 120 is open, the process returns to step S108. On the other hand, if the external cover 120 is closed, that is, if the external cover 120 is closed after the transition to the replacement operation mode, the operation by the user has been completed and the normal operation mode (step S104) is entered.

  Next, the exchange operation executed when the exchange instruction button is pressed will be described with reference to FIGS. In this apparatus, the exchange operation shown in FIG. 10 is executed as the exchange operation in step S113 of FIG.

  In the exchange operation (FIG. 10), first, pre-exchange processing is executed (step S401). The contents of the pre-replacement process are as shown in the flow shown in FIG. That is, the developing unit 4 is moved to the developing position (step S501), information indicating the usage status of the developing device is written in the memory provided in the developing device of the selected toner color (step S502), and then selected. The developing unit 4 is moved and positioned at a detachable position at which the developing device is detachable (step S503). As a result, the user can open and close the internal cover 130 to perform the attaching / detaching operation of the developing device.

  Returning to FIG. 10, when the pre-replacement process (step S401) is completed, the user waits for the external cover 120 to be closed (step S402). When the external cover 120 is closed, it is determined whether or not the developer has been replaced by the user (step S403). The criterion here is whether the opening / closing operation of the inner cover 130 has been performed at least once before the outer cover 120 is closed. That is, if the inner cover 130 is opened and closed after the replacement instruction button is pressed and before the outer cover 120 is closed, it can be estimated that the developer has been replaced. When the outer cover 120 is closed without opening / closing the inner cover 130, the developing device is not replaced. Such a determination can be made by monitoring the terminal voltages of the limit switches 122 and 132 provided corresponding to the two covers.

  If the developing device has been replaced, that is, if the inner cover 130 has been opened or closed, a predetermined post-replacement process is immediately executed (step S404). The contents of the post-exchange process are as shown in the flowchart of FIG. That is, first, the development unit 4 can be rotated and driven by shifting from the all-stop mode to the replacement operation mode (step S511). The subsequent step S512 is a processing step for determining whether or not the user has changed the developing device. Here, as described above, since it is presumed that the replacement operation has been performed by detecting the opening / closing of the inner cover 130, the determination here is “YES”, and each processing after step S 513 is subsequently executed. To do. That is, the development unit 4 is moved to the development position (step S513), and information stored in the memory of the newly installed developer is read (step S514). The information read out in this manner is stored in the RAM 108 of the engine controller 10, and the CPU 101 can refer to the information as needed and update and store the contents as necessary, thereby appropriately managing the usage history of each developing device. it can.

  Then, the replacement instruction flag is cleared (step S515), and the developing unit 4 is moved to the home position (HP) (step S516). Thus, a series of exchange operations is completed.

  Returning to FIG. 10, when the developing unit is not replaced, that is, when the outer cover 120 is closed without opening / closing the inner cover 130, “NO” is determined in step S403. In this case, the post-replacement process is not performed immediately, but the post-replacement process is performed after a predetermined time has elapsed. That is, a new time measurement is started independently of the time measurement for determining the neglected state (step S101 in FIG. 8) (step S405), and after the replacement if the predetermined time, for example, 5 seconds elapses. While the process is executed (step S406), if the external cover 120 is opened again during that time, the process returns to step S402 to wait for the cover 120 to be closed again (step S407).

  In the post-replacement process (FIG. 12) that is executed after a predetermined time has elapsed after the external cover 120 is closed without the developer being replaced (that is, when “YES” is determined in step S406), The determination in S512 is “NO” because the developing device has not been replaced, and in this case, steps S513 and S514 are skipped. This is because the currently installed developing unit is the same as that originally installed in the apparatus, and the contents of the memory in the developing unit are already known on the apparatus main body side and need not be newly read out. The above is the content of the exchange operation.

  As described above, the state transition of the apparatus when the image signal from the external apparatus is not given has been described. However, when a new image signal is input from the external apparatus, the operation differs from the above. First, when an image signal is given in a state where the apparatus may allow the image forming operation to be executed, that is, when the outer cover 120 and the inner cover 130 are both closed, the execution of the above flow is immediately stopped and the image is An image forming operation corresponding to the signal is executed. For example, if both covers are closed when an image signal is given during execution of the power saving mode, the CPU 101 outputs an H level enable control signal to each part of the apparatus. As a result, the apparatus returns from the power saving mode to the normal operation mode, and executes an image forming operation corresponding to the image signal.

  On the other hand, when an image signal is given with one of the covers open, the image forming operation is impossible, so the apparatus maintains the current state and performs predetermined notification to the external apparatus. Thereby, on the external device side, it is possible to grasp that the image forming apparatus 1 is in a state where the image forming operation cannot be performed, and to take appropriate measures such as stopping the transmission of the image signal or notifying the user. . Further, even when the cover is closed, the same can be done when a necessary unit is not mounted.

In summary, the state transition of the image forming apparatus 1 is as follows:
(1) In the normal operation mode, when the image signal is not given and the user does not perform any operation for a predetermined time (10 minutes in the above example), the mode is shifted to the power saving mode. In the power saving mode, the operation of the 24V power supply 224 is stopped, so the power consumption is low;
(2) When the normal operation mode is being executed or when the power saving mode is being executed and the outer cover 120 and the inner cover 130 are both closed, when an image signal is given, the normal operation mode is immediately executed and the image forming operation is performed. I do;
(3) When the external cover 120 is opened during execution of the normal operation mode, the operation mode is changed to the replacement operation mode. In the replacement operation mode, the developing unit 4 can be rotated so as to facilitate the replacement of the developing device by the user, while the other units are set in the operation stopped state and the image forming operation is prohibited. Furthermore, after shifting to the replacement operation mode, when left for a predetermined time, the mode shifts to the power saving mode. This reduces power waste when the device is left unattended;
(4) When the inner cover 130 is opened following the outer cover 120, the mode is shifted to the full stop mode. Thereby, the rotation of the developing unit 4 is prohibited. If it is left unattended in this state, it shifts to the power saving mode;
(5) The operation does not change even if the outer cover 120 is closed during the power saving mode, but returns to the normal operation mode when opened;
(6) When the external cover 120 is closed after the replacement instruction button is pressed, if it is determined that the developer has been replaced (more precisely, the internal cover 130 is opened / closed) before that, Immediately execute post-replacement processing such as reading the memory contents of the developer. On the other hand, when the outer cover 120 is closed without opening / closing the inner cover 130, the post-replacement process is executed after a predetermined start waiting time (5 seconds in the above example) elapses.

  Here, the reason for the above operation (5) is as follows. The reason why the user opens the cover of the device in the power saving mode is considered to have an intention to perform some operation on the device. On the other hand, if the execution of the power saving mode is continued, the device does not operate, which is contrary to the user's intention. In particular, as in the present embodiment, in an apparatus configured to allow the developing unit to be attached and detached by driving the developing unit 4, when the cover is opened, the apparatus exits the power saving mode and performs some operation, at least the unit. It is desirable that the exchange operation is possible. On the other hand, when the external cover 120 is closed during execution of the power saving mode, it is not always necessary to exit the power saving mode. This is because if the cover is closed, it can be returned to the normal operation mode triggered by another operation (for example, input of an image signal from an external device), and the cover that has been left open is simply closed. This is because it is not always necessary for the apparatus to perform any operation.

  Therefore, this apparatus maintains the current state when the outer cover 120 is closed during execution of the power saving mode, while returning to the normal operation mode when the outer cover 120 is opened. Thereby, the operation desired by the user can be executed promptly. When the external cover 120 is opened, it is necessary that at least the developing unit 4 can be rotated so that the developing device can be attached and detached. On the other hand, the image forming operation can be performed with the cover open. There is no need to do so. In this apparatus, if the external cover is opened, even after returning to the normal operation mode, the operation mode immediately shifts to the replacement operation mode, so that the developing device or the like can be replaced in this state.

  The reason for the operation as described in (6) above is as follows. The operation of pressing the replacement instruction button is performed by the user for the purpose of replacing the developing device. However, after pressing the instruction button, the external cover 120 may be closed without replacing the developing device due to an operation error or the like. In such a case, if the post-replacement processing is executed each time, the developer cannot be taken out (or attached) immediately after the user opens the cover again, and the user has to start the operation from the beginning. . On the other hand, if an appropriate start waiting time is provided after the external cover 120 is closed until the post-replacement process is started as in the present embodiment, even if the user closes the external cover 120 once, it will be a mistake. If it is noticed and opened immediately, the state in which the developing device can be attached and detached is maintained, and the above-mentioned problem does not occur.

  When the developing device is replaced, it is not necessary to provide such a start waiting time, and it may lead to user dissatisfaction with the fact that the apparatus does not operate immediately. Therefore, when it can be considered that the developing device has been attached / detached, specifically, the user can open / close the inner cover 130 in a state where the developing device can be attached / detached (that is, the developing unit 4 is stopped at the attaching / detaching position). When the operation is performed, the post-replacement process is executed immediately after the outer cover 120 is closed. At least the waiting time should be shorter than when the inner cover 130 is not opened or closed.

  In addition, since the user does not intend to attach / detach the developing device, there may be a case where the external cover 120 is closed without attaching / detaching the developing device. Therefore, when the state in which the outer cover 120 is closed continues to some extent, it is preferable to perform post-replacement processing. If the waiting time until the operation starts after the cover is closed is too short, it is inappropriate as a measure for an operation error. On the other hand, if it is too long, the subsequent operation will be delayed. is there.

  As described above, in the image forming apparatus of this embodiment, the external cover 120 is opened, and the replacement instruction button 151Y of the developing device operation unit 150 is operated, so that the developing device 4Y can be attached and detached. More specifically, the developing unit 4 is stopped at the attachment / detachment position. In this state, the user can open / close the inner cover 130 and perform the attaching / detaching operation of the developing device 4Y and the like. When the external cover 120 is closed in this state, the post-replacement process is executed and the developing unit 4 is rotated so that the developing device cannot be attached or detached. At this time, the waiting time until the post-replacement processing is started after the outer cover is closed is configured to be different from each other depending on whether or not the developing device is attached / detached before the outer cover 120 is closed. More specifically, when the external cover 120 is closed after the developing device is attached / detached, the post-replacement process is immediately performed. On the other hand, when the external cover 120 is closed without being attached / detached, the process waits about 5 seconds. After the elapse of time, execution of post-exchange processing is started. Whether or not the developing device is attached / detached is determined based on whether or not the inner cover 130 is opened / closed.

  By doing in this way, the following effects are obtained. First, when the external cover 120 is closed after the developing device is attached / detached, the apparatus can immediately start the operation and perform the next operation, for example, the image forming operation. On the other hand, even if the user accidentally closes the external cover 120 without attaching or detaching the developing device, the post-replacement process does not start immediately, so if the user opens the external cover 120 again during the waiting time, No processing is performed and the apparatus is maintained in a state just before the cover is closed. That is, since the developing unit 4 remains stopped at the attachment / detachment position, the user can immediately perform the attachment / detachment work.

  As described above, in this embodiment, the developing devices 4Y, 4M, 4C, and 4K correspond to “process units” of the present invention. The developing unit 4 that is mounted with these developing units and is positioned at the mounting / demounting position and other positions to switch the apparatus to a detachable / impossible state of the developing unit is referred to as “ It functions as “development rotary” and “switching means”. Further, the driver 48D and the motor 48M that rotationally drive the developing unit 4 correspond to the “driving means” of the present invention. Further, the engine controller 10 that controls the operation of each of these parts, more specifically, the CPU 101 functions as the “control unit” of the present invention. The outer cover 120 covering the engine unit EG corresponds to a “cover member”. The developing device operation unit 150 including the replacement instruction button 151Y for each toner color corresponds to the “instruction input unit” of the present invention.

  In this embodiment, the inner cover 130 covering the developing device opening 135, which is the “removing port” of the present invention, functions as a “regulating member” that restricts the mounting and dismounting of the developing device. The limit switch 132 that functions as “detecting means” of the present invention. Further, the memories 91 to 94 provided in each developing device 4Y or the like function as “storage means” of the present invention. Furthermore, in this embodiment, the post-replacement process (FIG. 11) performed in the replacement operation of FIG. 10 corresponds to the “detachment prohibition process” according to the present invention.

Second Embodiment
FIG. 13 is a view showing the appearance of a second embodiment of the image forming apparatus according to the present invention. The major difference between the apparatus of the second embodiment and the apparatus of the first embodiment is that the apparatus of the second embodiment is not provided with an internal cover that covers the developing device opening. Accordingly, in the apparatus of the second embodiment, a configuration for detecting opening / closing of the inner cover is omitted. Since other apparatus configurations are substantially the same as those of the apparatus of the first embodiment described above, the same components are denoted by the same reference numerals and description thereof is omitted. Note that the external cover 320 and the developing device opening 335 in the second embodiment have different shapes from the corresponding configurations in the first embodiment, and thus are given different reference numerals.

  In the apparatus of this embodiment, instead of the developing device operation unit 151 provided in the apparatus of the first embodiment, an operation unit 13 that receives a replacement instruction from the user is provided on the front surface of the upper panel of the apparatus. Yes. The operation unit 13 functions as the “instruction input unit” of the present invention, like the developing device operation unit 151 in the apparatus of the first embodiment. In this embodiment, when the user performs a predetermined replacement instruction operation on the operation unit 13 with the external cover 320 closed, the developing unit 4 rotates and moves to the attachment / detachment position. Further, the rotation of the developing unit 4 is prohibited until the outer cover 320 is closed. Hereinafter, of the operation of the apparatus according to the second embodiment, differences from the first embodiment described above will be described.

  FIG. 14 is a flowchart for explaining the transition of the operation mode in the second embodiment. First, the operation when the user does not open or close the cover or replace the cover is basically the same as that in the first embodiment (steps S601 to S604). However, the contents of the sleep process (step S603) are different with the difference in apparatus configuration. In this embodiment, when the external cover 320 is opened by the user, the mode immediately shifts to the full stop mode and the rotation of the developing unit 4 is prohibited (steps S605 and S606). Therefore, in this state, the user cannot perform the attaching / detaching operation of the developing device. On the other hand, when the cover is closed, it always waits for an exchange instruction from the user (step S607), and when an exchange instruction is accepted, an exchange operation described later is executed (step S608).

  FIG. 15 is a flowchart showing sleep processing in this embodiment. As described above, in this embodiment, the developing device can be attached and detached only when the user inputs a replacement instruction to the operation unit 13 with the external cover 320 closed. Therefore, in the sleep process in this embodiment, when the external cover 320 is opened after the apparatus has shifted to the power saving mode (step S211), the state of the apparatus does not change until it is closed again (step S212). If there is an exchange instruction from the user with the cover closed (step S213), an exchange operation is executed (step S214). When an image signal is given from the outside, the power saving mode is canceled and the normal operation is resumed (step S215). In other cases, the power saving mode is continuously maintained.

  FIG. 16 is a flowchart showing the exchange operation in this embodiment. When a replacement instruction input from the user is accepted, pre-replacement processing is executed as in the apparatus of the first embodiment to move the developing unit 4 to the attachment / detachment position and start time measurement by an internal timer (steps S701 and S702). . Here, the process waits for the external cover 320 to be opened (step S703). If the external cover 320 is not opened after a predetermined time (for example, 5 minutes), the developing unit 4 is determined to have been replaced. Return to the home position (step S705).

  On the other hand, when the external cover 320 is opened, time measurement by a timer different from the above-described timer is started (step S706). Then, the timing is continued while the outer cover 320 is opened, and the timing is stopped when the outer cover 320 is closed (steps S707 and S708). As a result, the time during which the external cover 320 has been opened is counted. Then, based on the timing result, it is determined whether or not the developing device has been replaced (step S709).

  In the apparatus according to the first embodiment, the presence / absence of replacement work is determined based on whether the inner cover is opened or closed. On the other hand, in the apparatus according to the second embodiment in which no internal cover is provided, the presence / absence of replacement work is determined based on the above-described time measurement result, that is, the time during which the external cover 320 is open. That is, since a certain amount of time is required for replacing the developing device, if the time during which the external cover 320 is opened is shorter than the time required for the operation, it can be determined that the replacement operation has not been performed. For example, if the external cover 320 is opened and closed again after a few seconds, it is unlikely that the developer has been replaced during that time. On the other hand, if the time that the external cover 320 has been opened is sufficiently long, it can be said that there is a high probability that the developer has been replaced during that time. Therefore, in this embodiment, if the time that the external cover 320 has been opened, which is timed by the internal timer, is less than or equal to a predetermined value (for example, 10 seconds), it is determined that the replacement has not been performed. When it is open, it is determined that the exchange has been made.

  If it is determined that the developer has been replaced, the post-replacement process is immediately executed (step S713). The contents of the post-exchange process are the same as those in the first embodiment (FIG. 12). On the other hand, when it is determined that no replacement has been made, a new time measurement is started (step S710), and after a predetermined time has elapsed (step S711), post-exchange processing is executed. The “predetermined time” here has the same meaning as the “start waiting time” in the first embodiment, and is a waiting time provided to relieve a user's operation mistake. When the external cover 320 is opened during this waiting time (step S712), the process returns to step S706.

  As described above, in the image forming apparatus according to this embodiment, it is determined whether or not the developing device has been replaced based on the length of time that the external cover 320 has been opened after the replacement instruction is given by the user. ing. Then, according to the determination result, the time from when the external cover 320 is closed until the developing unit 4 starts rotating is changed. By doing so, also in the second embodiment, it is possible to obtain the same function and effect as the apparatus of the first embodiment.

<Modification>
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, each of the above embodiments is an apparatus that allows the developing device 4Y or the like as a “process unit” of the present invention to be detachable by a rotational positioning operation of the developing unit 4 that is a “switching unit”. However, the present invention is not limited to this. For example, an electromagnetic lock mechanism for fixing the photosensitive unit 2 or another unit is provided, and the unit can be taken out by operating this to release the lock. The present invention can also be applied to an apparatus. In this case, the unit is the “process unit” of the present invention, and the lock mechanism functions as the “switching unit”.

  In the first embodiment, whether or not the developing device 4Y is attached or detached is determined by detecting the opening / closing of the inner cover 130 covering the developing device opening 135 by the limit switch 132. However, in addition to such limit switches, for example, attachment / detachment may be detected by a sensor based on an optical or electromagnetic principle such as a photo interrupter or a reed switch. Further, these sensors may be attached to the support frame 40 of the developing unit 4 to detect whether or not the developing device is attached to the frame 40.

  Moreover, the determination method of the presence or absence of the exchange work in 2nd Embodiment can also be applied to the apparatus of 1st Embodiment. That is, in the apparatus of the first embodiment, when the inner cover 130 is opened and then closed again, it is determined that the developing device has been attached or detached. By changing this, even if the opening / closing of the inner cover 130 is detected, if the opening time is short, it may be determined that the developing device has not been attached or detached.

  In each of the above embodiments, in the post-replacement process, the developer memory is read only when the developer is attached or detached. However, the present invention is not limited to this. For example, the reading may be performed every time the post-exchange process is executed. However, in order to suppress the wear of the connectors 109, 49Y, etc., it is desirable to reduce the number of fittings as much as possible, and from this point of view, it is desirable to use this embodiment. Further, in the case where a memory is not provided in a unit corresponding to the “process unit” in the present invention in the developing unit or other units, such a reading operation is naturally unnecessary.

  The first embodiment includes the inner cover 130 for attaching and detaching the developing device, and the replacement instruction button 151Y for moving the developing unit 4 to the attaching and detaching position. The present invention can also be applied to an apparatus that does not include the above. The present invention is particularly effective in an apparatus that shifts to a state in which a process unit can be attached and detached in response to a request from a user or an external apparatus.

  Further, the present invention is not limited to the configuration of the above-described embodiment. For example, a device that includes a developing device that supports black toner and forms a monochrome image, a device that includes a transfer medium (transfer drum, transfer sheet, etc.) other than the intermediate transfer belt, Furthermore, the present invention can also be applied to other image forming apparatuses such as copying machines and facsimile machines.

1 is a diagram illustrating a first embodiment of an image forming apparatus according to the present invention. FIG. FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus in FIG. 1. FIG. 2 is an external perspective view of the image forming apparatus in FIG. 1. FIG. 3 is a diagram illustrating a power feeding path of the image forming apparatus. FIG. 4 is a schematic diagram showing a stop position of a developing device cartridge. FIG. 3 is a diagram illustrating a developing device operation unit of the image forming apparatus. The figure which shows a response | compatibility with each operation mode and the setting value of each control signal. The flowchart explaining the transition of the operation mode in 1st Embodiment. The flowchart which shows a sleep process. The flowchart which shows replacement | exchange operation | movement. The flowchart which shows the process before replacement | exchange. The flowchart which shows the process after replacement | exchange. The figure which shows the external appearance of 2nd Embodiment of the image forming apparatus concerning this invention. The flowchart explaining the transition of the operation mode in 2nd Embodiment. The flowchart which shows the sleep process in this embodiment. A flow chart which shows exchange operation in this embodiment.

Explanation of symbols

  4 ... development unit (development rotary, switching means), 4Y, 4M, 4C, 4K ... developer (process unit), 10 ... engine controller (control means), 13 ... operation unit (instruction input means), 48D ... driver ( Drive means), 48M ... motor (drive means), 120, 320 ... outer cover (cover member), 130 ... inner cover (regulation member), 132 ... limit switch (detection means), 150 (151Y, 151M, 151C, 151K) ) ... Developer operation section (instruction input means), 224 ... DC power supply (power supply section)

Claims (10)

A process unit configured to be detachable from the apparatus body;
Switching means for switching the apparatus between a detachable state and a non-detachable state of the process unit;
A cover member configured to be openable and closable with respect to the apparatus main body, and restricting a user to attach or detach the process unit in the closed state;
Control means for controlling the switching means,
The control means includes
If the cover member is closed when the apparatus is in a state where the process unit can be attached / detached, an attachment / detachment prohibition process is performed for controlling the switching means to switch the apparatus to a state where the process unit cannot be attached / detached. And,
If the process unit is not attached / detached before the cover member is closed, the execution of the attachment / detachment prohibition process is started after the cover member is closed, compared to the case where the process unit is attached / detached. An image forming apparatus characterized in that the start waiting time until the start is extended.   The image forming apparatus according to claim 1, wherein the control unit stops the execution of the attachment / detachment prohibiting process when the cover member is opened during the start waiting time. A detection means for detecting a change in the state of the apparatus related to whether or not the process unit has been attached or detached;
The image forming apparatus according to claim 1, wherein the control unit determines whether the process unit is attached or detached based on a detection result of the detection unit. The process unit is configured to be attachable / detachable through an attaching / detaching port provided in the apparatus main body, and is provided so as to be openable / closable with respect to the attaching / detaching port and restricts attachment / detachment of the process unit in the closed state. Further comprising
The detection means is configured to detect opening and closing of the restriction member,
The image forming apparatus according to claim 3, wherein the control unit determines that the process unit is attached or detached when the detection unit detects that the restriction member is closed again after being opened.   The image forming apparatus according to claim 4, wherein the control unit determines that the process unit is not attached or detached when a time period from when the restriction member is opened to when it is closed again is equal to or shorter than a predetermined time. The detection means is configured to detect opening and closing of the cover member,
The image forming apparatus according to claim 3, wherein the control unit determines that the process unit is not attached or detached when a time period from when the cover member is opened to when it is closed again is a predetermined time or less. The process unit includes storage means for storing information about the unit,
The image forming apparatus according to claim 1, wherein the control unit performs an operation of reading the information from the storage unit in the attachment / detachment prohibition process performed after the process unit is attached / detached. Further comprising an instruction input means for accepting a process unit attachment / detachment instruction from a user;
The image forming apparatus according to claim 1, wherein when the instruction is input to the instruction input unit, the control unit puts the process unit into a detachable state by the switching unit. The developing unit as the process unit is configured to be attachable, and further includes a developing rotary that is rotated by a driving unit,
The driving means functions as the switching means by selectively positioning the developing rotary at a predetermined attaching / detaching position or other position determined corresponding to the developing device and allowing the developing device to be attached / detached. The image forming apparatus according to claim 1. A process unit configured to be detachable with respect to the apparatus main body, a switching unit for switching the apparatus between a detachable state and a non-detachable state of the process unit, and configured to be openable and closable with respect to the apparatus main body. In the control method of the image forming apparatus comprising the cover member that restricts the user to attach and detach the process unit in the closed state,
If the cover member is closed when the apparatus is in a state where the process unit can be attached / detached, an attachment / detachment prohibition process is performed for controlling the switching means to switch the apparatus to a state where the process unit cannot be attached / detached. And,
If the process unit is not attached / detached before the cover member is closed, the execution of the attachment / detachment prohibition process is started after the cover member is closed, compared to the case where the process unit is attached / detached. A control method for an image forming apparatus, wherein a start waiting time until the start is increased.

Images