JP4360173B2 - Image forming apparatus and method for controlling the apparatus - Google Patents

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. 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.

  On the other hand, this type of image forming apparatus is required to reduce power consumption in a state where no image forming operation is performed, so-called standby power. For this purpose, an apparatus capable of stopping a power supply circuit for supplying power to a large power load such as a motor as needed has been proposed. For example, the image recording apparatus described in Patent Document 2 is configured such that power supply to a power-type power supply circuit can be turned on / off by microcomputer control.

JP 2002-333756 A (FIG. 3) Japanese Unexamined Patent Publication No. 2000-333459 (for example, paragraph 0024)

  Also in the above-described image forming apparatus of Patent Document 1, it is conceivable to use the technique described in Patent Document 2 in order to reduce standby power. However, there are cases where the user desires to replace the unit during standby, and the power supply circuit cannot be stopped in order to meet this requirement. This is because when the unit is attached / detached, a rotational positioning operation of the developing rotary is required, and when the power supply circuit is stopped, the operation becomes impossible.

  For this reason, in an apparatus configured to interpose the operation of the apparatus itself to the user's unit attaching / detaching operation, it is desired to establish a control technique that achieves both reduction in standby power and convenience of the unit attaching / detaching operation by the user.

  The present invention has been made in view of the above problems, and provides an image forming apparatus and a control method therefor that enable a user to attach and detach a process unit with good workability and suppress wasteful power consumption. For the purpose.

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, the image forming apparatus including the cover member that restricts the user to attach or detach the process unit in the closed state and the control method thereof include the switching unit included in each part of the apparatus. By stopping the operation of the image forming unit, a power saving mode in which the power consumption of the apparatus is less than that in the image forming operation is executed , and the execution of the power saving mode is continued when the cover member is closed during the power saving mode. on the other hand, when the cover member during the power saving mode is opened, the cutting device to stop the execution of the nodal electric mode It is characterized in that shifting to state enabling the operation of the example means.

In the invention configured as described above, the power consumption during standby can be kept low by executing the power saving mode with low power consumption. Even when the power saving mode is being executed, execution of the power saving mode is continued when the cover member that restricts the user's attachment / detachment operation is closed, and when the cover member is opened, the power saving mode is restored. In the image forming apparatus according to the present invention, the process unit cannot be attached / detached when the cover member is closed, and can be attached / detached only when the cover member is opened. That is, the user first follows the procedure of opening the cover member and then performing the process unit attachment / detachment operation. Therefore, if the execution of the power saving mode is interrupted when the cover member is opened so that the switching means can be operated, it is possible to appropriately and promptly respond to the subsequent attaching / detaching operation. As described above, according to the present invention, it is possible to configure an image forming apparatus that consumes less power during standby and that is excellent in user convenience in attaching and detaching operations.

  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. You may do it. 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.

  The instruction input means may be configured not to accept a user instruction input to the instruction input means when the cover member is closed. In order to achieve such a configuration, for example, the instruction input means can be provided at a position where the cover member is shielded by the cover member in the closed state. By doing so, the cover member is first opened, and then the instruction input to the instruction input means is performed, and the power saving mode is stopped when the cover member is opened. Can respond quickly.

  Further, if the operation of the power supply unit that supplies power to the switching means is stopped in the power saving mode, the power consumption in the power saving mode can be further reduced.

  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.

  Further, the power saving mode may be started when a state in which there is no operation request from an external device or a user connected to the image forming apparatus continues for a predetermined time. That is, when the apparatus is left for a predetermined time in a state where an image forming operation is possible, the power consumption mode of the apparatus in the left state can be suppressed by shifting to the power saving mode. In this case, it is not necessary to consider the open / closed state of the cover member as a condition for starting execution of the power saving mode. In other words, whether the cover member is open or closed, the power consumption of the device is suppressed by shifting to the power saving mode when the device is left for a predetermined time. Can do. At this time, it is not always necessary to stop the power saving mode when the open cover member is closed. However, when the closed cover member is opened, the power saving mode is canceled so that the user can perform the attaching / detaching operation. Can respond quickly.

  FIG. 1 is a view showing an 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 a calculation result in the CPU 111 and other information. It is a RAM that temporarily stores 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.

  As these RAMs 107, 117 and 91 to 94, in order to store information on the usage status of each part of the apparatus, it is preferable to use a non-volatile memory in which information is retained even in a non-energized state. For example, a flash memory or a ferroelectric memory can be used.

  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 107 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 107 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, 10 and 11 are flowcharts showing the sleep process, the exchange operation 1 and the exchange operation 2, respectively. Further, FIG. 12 is a flowchart showing pre-replacement processing and post-replacement processing.

  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, whereby the developing device can be attached and detached, while the other units, that is, the photosensitive unit 2 and the transfer unit 7 are stopped. It is possible to keep power consumption low compared to the operation mode. 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. For example, the time from the end of the image forming operation to the start of the power saving mode is almost the same in the case of shifting to the power saving mode without going through the switching operation mode and in the case of shifting to the power saving mode via the switching operation mode. In addition, the “predetermined time” in step S108 may be set according to the time elapsed from the end of image formation to the transition to the replacement operation mode.

  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 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 1 shown in FIG. 10 or the exchange operation 2 shown in FIG. 11 is executed as the exchange operation in step S113 of FIG.

  In the exchange operation 1 (FIG. 10), first, a pre-exchange process (step S301) is executed. The contents of this pre-exchange process are as shown in the flow on the left side of 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, in this state, it waits for the developer to be replaced by the user. Here, it is presumed that the developing device has been replaced when the inner cover 130 covering the developing device opening 135 is opened and closed again (steps S302 and S304), and the post-replacement processing (step S305) is executed. To do. However, while the inner cover 130 is opened, the apparatus is in the all stop mode to prohibit the rotation of the developing unit 4 (step S303).

  The contents of the post-exchange process are as shown in the flow on the right side 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. This is a process that has meaning in the exchange operation 2 described later. As described above, in the exchange operation 1, it is estimated that the exchange operation was performed by detecting the opening / closing of the inner cover 130. The determination is always “YES”, and each process after step S513 is subsequently executed. 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). 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.

  On the other hand, the exchange operation 2 (FIG. 11) is configured as follows. First, the pre-replacement process similar to the replacement operation 1 is executed (step S401), and then 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, the post-replacement process similar to the replacement operation 1 is immediately executed (step S404). On the other hand, when the developing unit is not replaced, that is, when the outer cover 120 is closed without opening / closing the inner cover 130, the processing is not performed immediately but is replaced after waiting for a predetermined time. Perform post-processing. 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 contents of the exchange operation 2.

  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.

To summarize the above, the state transitions of the image forming apparatus 1 are organized 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 to perform the image forming operation. 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 to prohibit the image forming operation. 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) Although the operation does not change even if the outer cover 120 is closed during the power saving mode, it returns to the normal operation mode when opened. The reason for this 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.

Further, when the replacement operation 2 shown in FIG. 11 is adopted as the replacement operation (step S113) in FIG. 8, the following operation is performed in addition to the above (1) to (5).
(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 and closing the inner cover 130, the post-replacement process is executed after a predetermined waiting time (in the above example, 5 seconds) has elapsed. The reason for this 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, 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.

  It is not necessary to provide such a start waiting time when the developing device is replaced. In addition, if this period is too long, a time delay occurs until the next operation starts. Therefore, about several seconds is appropriate as this period.

  As described above, in the image forming apparatus according to this embodiment, when the image forming apparatus is left without being given an image signal for a predetermined time, it shifts to a power saving mode with lower power consumption. Can be suppressed. In particular, since the operation of the high power 24V power supply 224 is stopped, the power consumption in the power saving mode can be minimized. This power saving mode is executed not only when the apparatus is left with the external cover 120 closed and an image forming operation is possible, but also when the external cover 120 is left open.

  On the other hand, even when the power saving mode is being executed, when it is detected that the external cover 120 has been opened, the execution of the power saving mode is immediately stopped, the normal operation mode or the replacement operation mode is entered, and the developing unit 4 is rotated. The drive is ready. For this reason, the developing unit 4 can be moved to a predetermined position in response to the pressing of the replacement instruction button by the user without delay. As a result, the user can perform the attaching / detaching operation of the developing device with good workability.

  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 rotate the development unit 4 correspond to the “driving means” of the present invention, and the power source 224 that supplies power to these corresponds to the “power source unit” 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.

  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, in the above-described embodiment, the developing device 4Y or the like as the “process unit” of the present invention is detachable by the rotational positioning operation of the developing unit 4 that is the “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 a “process unit” of the present invention, and the lock mechanism functions as a “switching unit”.

  In this embodiment, the operation of each part is permitted / prohibited by an enable control signal given to each part of the apparatus from the CPU 101. However, the present invention is not limited to this. For example, when the external cover is opened, other than the developing unit 4 In order to prohibit the operation of a part of the apparatus, power supply may be cut off by an interlock switch which is a known technique.

  In addition, the present embodiment includes an internal cover 130 for attaching and detaching the developing device, and an exchange instruction button 151Y for moving the developing unit 4 to the attaching and detaching position. However, one or both of these are provided. It is possible to apply the present invention to a device that does not have this. 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 an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a block diagram illustrating 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. It is a figure which shows the electric power feeding path | route of this image forming apparatus. FIG. 6 is a schematic diagram illustrating a stop position of a developing device cartridge. FIG. 3 is a diagram illustrating a developing device operation unit of the image forming apparatus. It is a figure which shows a response | compatibility with each operation mode and the setting value of each control signal. It is a flowchart for demonstrating the transition of the operation mode in this apparatus. It is a flowchart which shows a sleep process. 3 is a flowchart showing an exchange operation 1; 6 is a flowchart showing an exchange operation 2; It is a flowchart which shows the process before replacement | exchange, and the process after replacement | exchange.

Explanation of symbols

4 ... development unit (development rotary, switching means), 4Y, 4M, 4C, 4K ... developer (process unit), 10 ... engine controller (control means), 48D ... driver (drive means), 48M ... motor (drive means) 120 ... External cover (cover member), 150 (151Y, 151M, 151C, 151K) ... Developer operation section (instruction input means), 224 ... DC power supply (power supply section)

Claims (7)

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;
A control unit capable of executing a power saving mode in which power consumption of the apparatus is less than that during the image forming operation by stopping a part of the operation including the switching unit among the units of the apparatus;
The control means continues to execute the power saving mode when the cover member is closed during execution of the power saving mode, while when the cover member is opened during execution of the power saving mode , the control means And the apparatus is shifted to a state in which the switching means can be operated. The control means maintains execution of the power saving mode when an image signal is input from an external device while the power saving mode is being executed with the cover member closed, unless the process unit is mounted. The image forming apparatus according to claim 1. Further comprising an instruction input means for accepting a process unit attachment / detachment instruction from a user;
3. The image forming apparatus according to claim 1, wherein the control unit puts the process unit into a detachable state by the switching unit when an instruction is input to the instruction input unit. The image forming apparatus according to claim 3 , wherein the instruction input unit is configured not to accept a user instruction input to the instruction input unit when the cover member is closed. A power supply for supplying power to the switching means;
It said control means, the image forming apparatus according to any one of 4 claims 1 stops the operation of the power supply unit in the power saving mode. 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. It claims 1 to to the image forming apparatus according to any one of 5. 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,
When necessary, a power saving mode for reducing the power consumption of the apparatus compared to the time of the image forming operation is performed by stopping a part of the operation including the switching unit in each part of the apparatus.
When the cover member is closed during execution of the power saving mode, the execution of the power saving mode is continued, while when the cover member is opened during execution of the power saving mode, the execution of the power saving mode is stopped. A control method for an image forming apparatus, wherein the apparatus is shifted to a state in which the switching means can be operated.

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