JP2009145388A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, when an image formation is interrupted by the operation of opening a door 32, capable of preventing jamming and misprinting of a recording material, by preventing entry of hand fingers into an apparatus body. <P>SOLUTION: When a start switch 16 is operated with the door 32 closed, a locking device 40 is actuated to prevent the opening of the door 32 during the image formation. When a user attempts to open the door 32 during the image formation, a door switch 32s detects a lift of the door 32, waits that a toner image under the formation is finished to be transferred and fixed on the recording material, and releases the locking device 40. The fraction of the time the toner image at formation is finished in being transferred and fixed on the recording material is secured by the locking device 40 for safety, and then the door 32 is set openable. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus in which a toner image formed using a high voltage is transferred to a recording material and fixed by a fixing device, and more particularly to a door structure that shields a toner image forming portion and a recording material conveyance path.

  2. Description of the Related Art Image forming apparatuses that transfer a toner image formed using a high voltage onto a recording material fed by a feeding mechanism and then heat-fix the toner image on the recording material using a fixing device are widely used.

  In the image forming apparatus, the paper feeding mechanism and the high voltage application unit are shielded by a sturdy housing structure provided with a plurality of door members, and when the door member is opened to perform jam processing of the recording material, the entire apparatus Is automatically shut down.

  Patent Document 1 discloses an image forming apparatus in which when a door member is opened during image formation, image formation is interrupted in the middle, the recording material being processed is automatically discharged, and the power is shut off after completion of the automatic discharge. It is. As a result, the power supply is shut off when there is no recording material in the recording material conveyance path, so that troublesome jam processing does not have to be performed when the door member is closed and the power supply is turned on again.

JP-A-6-208263

  Since the automatic discharge processing of the recording material disclosed in Patent Document 1 interrupts the formation of the toner image, in many cases, the last recording material is discharged in a misprinted state where an incompletely fixed image is formed. End up. When the automatically discharged recording material is not misprinted, an untransferred toner image remains on the recording material, and the untransferred toner is cleaned and wasted.

  Moreover, although the high voltage is stopped, the automatic discharge processing of the recording material is executed in a state where the door member is opened and the finger can enter the body, as described in paragraph 0021 of Patent Document 1. In addition, it is necessary to arrange the door member at a position isolated from the recording material conveyance path.

  An object of the present invention is to provide an image forming apparatus capable of avoiding a jam or misprint of a recording material without allowing a finger to enter the body when image formation is interrupted by an operation of opening a door member or the like. It is said.

  An image forming apparatus according to the present invention includes a toner image forming unit that forms a toner image, a feeding mechanism that feeds a recording material and transfers the toner image, and heats and presses the recording material onto which the toner image is transferred. A fixing device for fixing an image; and a door member capable of shielding at least one of the toner image forming unit and the feeding mechanism. Then, a locking device that fixes the closed door member to prevent the opening and an image formation interruption command are received, and the toner image forming unit completes the formation of the toner image being executed and the fixing device fixes the image. And a control means for releasing the locking device after the operation is completed.

  In the image forming apparatus of the present invention, when an interruption command is generated by an operation of opening a door member or the like and image formation is interrupted, the locking device is used until the toner being formed is transferred to the recording material and fixed. Prevents the door member from being fixed and opened.

  When image formation is interrupted, including in the case of incorrect operation, the door member can be opened after the locking device has secured a short time from the completion of the transfer of toner to the recording material to the completion of fixing. To.

  Therefore, it is possible to avoid jamming or misprinting of the recording material without allowing the finger to enter the body.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present invention, when the image formation is interrupted, a part or all of the configuration of each embodiment can be used as an alternative as long as the door member is locked until the toner image being formed is transferred to the recording material and the fixing is completed. Another embodiment in which the configuration is replaced can also be implemented.

  Accordingly, the present invention is not limited to an image forming apparatus using an intermediate transfer member, and can be implemented by an image forming device that directly transfers a toner image formed on a photosensitive member to a recording material. Further, the present invention is not limited to the tandem type in which a plurality of photosensitive drums are arranged along the intermediate transfer body or the recording material conveyance body, but is also implemented in a single drum type in which one photosensitive drum is arranged along the intermediate transfer body or the recording material conveyance body. it can.

  In the present embodiment, only main parts related to toner image formation / transfer will be described. However, the present invention includes a printer, various printing machines, a copier, a fax machine, a composite machine, in addition to necessary equipment, equipment, and a housing structure. It can be implemented in various applications such as a machine.

  In addition, about the general matter of the image forming apparatus shown by patent document 1, illustration is abbreviate | omitted and the overlapping description is abbreviate | omitted. In the description, the reference symbols in parentheses attached to the configuration names used in the claims are examples for assisting understanding of the invention, and the configuration is limited to the corresponding members in the embodiments. Is not.

<First Embodiment>
FIG. 1 is an explanatory diagram of a housing structure of the image forming apparatus according to the first embodiment, FIG. 2 is an explanatory diagram of a configuration of the locking device, and FIG. 3 is an explanatory diagram of an internal configuration of the image forming apparatus according to the first embodiment.

  As shown in FIG. 1, the image forming apparatus 100 includes a door 31 that can be opened and closed to access the inside of the main body for maintenance such as toner replenishment, recording material jam processing, and consumable replacement, 32, 35, and 36 are attached. Doors 31 and 32 are attached to the front surface of the main body frame 30 so as to be horizontally openable and openable, and doors 35 and 36 are attached to the side surfaces so as to be openable and closable.

  Recording material storage cassettes 33 and 34 are arranged below the front side of the main body frame 30, and the recording material storage cassettes 33 and 34 are pulled out to the front side when the recording material is replenished to the image forming apparatus 100.

  The operation panel 15 is provided with a start switch 16 for starting image formation and a stop switch 17 for interrupting image formation.

  A power switch 60 for shutting off the power of the image forming apparatus 100 is disposed on the upper side of the main body frame 30.

  A door switch 32 s that detects the lifting of the door 32 is disposed at a position corresponding to the upper right portion of the door 32 in the main body frame 30.

  Inside the doors 31, 32, 35, and 36 are moving parts such as a recording material conveyance mechanism, a toner image forming unit, and a fixing device and parts to which a high voltage is applied. Reference numeral 36 denotes a protective cover for safety. Therefore, when the doors 31, 32, 35, and 36 are opened, the movable portion is stopped, the high-voltage power supply is shut off, image formation is interrupted, and safety during internal access is ensured.

  A thin plate 48 having an opening 48h is fixed to the lower right inside of the door 32, and the opening 48h of the thin plate 48 is locked to the main body frame 30 by a lock claw 44 so that the closed door 32 is opened. A locking device 40 to be locked is fixed.

  The thin plate 48 is actually attached to the doors 32, 35, and 36, respectively, and a plurality of locking devices 40 are attached to the main body frame 30 so that the lock claws 44 are engaged with the thin plates 48 of the doors 32, 35, and 36. Is arranged. However, in FIG. 1, only the locking device 40 of the front door 32 is illustrated.

  In the first embodiment, the locking / unlocking permission of the doors 32, 35, and 36 can be individually set by disposing and controlling the locking device 40 on the doors 32, 35, and 36, respectively. When the door 32 is closed and the locking device 40 is fastened, the door 32 is fixed and cannot be opened.

  As shown in FIG. 2, in the locking device 40, a lock claw 44 is rotatably provided on a pin 43 attached to a proper position of the main body frame 30. The urging spring 45 is engaged with the lock claw 44, and the urging spring 45 always gives the lock claw 44 a turning tendency in the direction of the arrow R4, so that the lock claw 44 is placed in the opening 48h of the thin plate 48. In contrast, the disengaged position is maintained.

  A solenoid 46 attached to a proper position of the main body frame 30 is connected to the lock claw 44. By operating the solenoid 46, the lock claw 44 takes the position shown in the figure against the action of the biasing spring 45. Engage with the opening 48 h of the thin plate 48.

  When the solenoid 46 is operated in a state in which the door 32 is closed, the tip end portion of the lock claw 44 pierces the opening 48h of the thin plate 48, and the subsequent opening of the door 32 is prevented.

  As shown in FIG. 1, when the start switch 16 is operated or a print job is received from the outside with the door 32 closed, the locking device 40 is activated to fasten the door 32 during image formation. To prevent opening.

  If the door 32 is forcibly opened during image formation, the door switch 32s detects the lifting of the door 32 and interrupts image formation, and the toner image being formed is transferred to the recording material and the fixing is completed. The locking device 40 is released after waiting. When the image formation is interrupted including the case of erroneous operation, the locking device 40 secures a short time from the completion of the transfer of the toner being formed to the recording material to the completion of fixing, and then the door 32 Allows opening.

  As a result, the operation for forcibly opening the door 32 is completed and the door 32 is naturally opened, and the recording material is not jammed or misprinted.

  As shown in FIG. 3, the image forming apparatus 100 according to the first embodiment includes a tandem type intermediate in which image forming portions Pa, Pb, Pc, and Pd of yellow, magenta, cyan, and black are arranged in a straight section of the intermediate transfer belt 9. It is a transfer type full-color printer.

  The image forming unit Pa forms a yellow toner image on the photosensitive drum 1 a and performs primary transfer onto the intermediate transfer belt 9. The image forming unit Pb forms a magenta toner image on the photosensitive drum 1 b and performs primary transfer by superimposing the yellow toner image on the intermediate transfer belt 9. The image forming unit Pc forms a cyan toner image on the photosensitive drum 1c, and performs primary transfer by superimposing the yellow and magenta toner images on the intermediate transfer belt 9. The image forming unit Pd forms a black toner image on the photosensitive drum 1d, and performs primary transfer on the yellow, magenta, and cyan toner images on the intermediate transfer belt 9.

  The yellow, magenta, cyan, and black toner images carried on the intermediate transfer belt 9 are conveyed to the secondary transfer portion T2 as the intermediate transfer belt 9 rotates, and are taken out from the recording material storage cassettes 33 and 34 one by one. Secondary transfer to the recording material P is performed. The recording material P waits at the registration roller 23 and is fed to the secondary transfer portion T2 in time with the toner image on the intermediate transfer belt 9.

  The recording material P onto which the toner image has been secondarily transferred is transferred to the fixing device 8 and is nipped and conveyed while being heated and pressurized to fix the toner image on the surface. The recording material P on which the toner image is fixed is discharged and stacked on the discharge tray 25.

  The transfer residual toner that passes through the secondary transfer portion T2 and remains on the intermediate transfer belt 9 is removed by the belt cleaning device 19.

  The intermediate transfer belt 9 is supported by the tension roller 12, the driving roller 13, and the opposing roller 10 and rotates in the direction of the arrow R2.

  The image forming portions Pa, Pb, Pc, and Pd are provided with developing devices 4a, 4b, 4c, and 4d that develop toner images using yellow, magenta, cyan, and black two-component developers, respectively.

  Connected to the upper portion of the image forming apparatus 100 are toner cartridges 7a, 7b, 7c, and 7d that supply replenishment developer to the developing devices 4a, 4b, 4c, and 4d.

  The image forming apparatus 100 executes a full color mode in which a full color image is formed using the image forming units Pa, Pb, Pc, and Pd as described above, and a black single color mode in which a monochrome image is formed using the image forming unit Pd. Is possible.

<Toner image forming means>
The image forming portions Pa, Pb, Pc, and Pd are configured in substantially the same manner except that the developing colors of the developing devices 4a, 4b, 4c, and 4d are different. Therefore, in the following, the yellow image forming portion Pa will be described, and for the magenta, cyan, and black image forming portions Pb, Pc, and Pd, the suffix a in the description is read as b, c, and d, respectively. Shall be understood.

  The image forming portion Pa surrounds the rotating photosensitive drum 1a and includes a charging roller 2a, an exposure device 3a, a developing device 4a, a primary transfer roller 5a, and a cleaning device 6a.

  The charging roller 2a rotates following the photosensitive drum 1a.

  The exposure device 3a scans the scanning line image data obtained by developing the yellow separated color image with a rotating mirror, and writes an electrostatic image of the image on the photosensitive drum 1a.

  The developing device 4a stirs and charges the two-component developer, carries the charged two-component developer on the developer carrying member, and slides on the photosensitive drum 1a.

  As the toner image is formed, only the toner of the two-component developer filled in the developing device 4a is taken out to the photosensitive drum 1a. Therefore, if left as it is, the ratio of the toner to the two-component developer in the developing device 4a is increased. descend. For this reason, toner corresponding to the amount of toner consumed in forming the toner image is replenished from the toner cartridge 7a to the developing device 4a.

  The primary transfer roller 5a is in pressure contact with the photosensitive drum 1a via the intermediate transfer belt 9, and forms a primary transfer portion T1 between the intermediate transfer belt 9 and the photosensitive drum 1a.

  The cleaning device 6a removes transfer residual toner remaining on the photosensitive drum 1a after passing through the primary transfer portion T1.

<High voltage, feeding mechanism>
FIG. 4 is a block diagram of a control system of the image forming apparatus.

  As shown in FIG. 4, the high voltage generator 61 applies a DC voltage on which an AC voltage is superimposed to the charging roller 2a to charge the surface of the photosensitive drum 1a to a uniform negative potential.

  The high voltage generator 61 applies a development voltage obtained by superimposing an alternating voltage on a negative direct current voltage to the developer carrying member of the developing device 4a to reversely develop the electrostatic image on the photosensitive drum 1a.

  The high voltage generator 61 applies a positive DC voltage to the primary transfer roller 5a, and primarily transfers the toner image to the intermediate transfer belt 9 that passes through the primary transfer portion T1 over the toner image on the photosensitive drum 1a.

  The secondary transfer roller 11 is pressed against the opposing roller 10 via the intermediate transfer belt 9 to form a secondary transfer portion T <b> 2 between the intermediate transfer belt 9 and the secondary transfer roller 11.

  The high voltage generation unit 61 applies a positive direct current voltage to the secondary transfer roller 11 and superimposes the toner image on the recording material that is nipped and conveyed by the secondary transfer unit T2 over the toner image on the intermediate transfer belt 9. Secondary transfer.

  The controller 62 controls the motor 18 to drive the photosensitive drum 1a, the developing device 4a, and the intermediate transfer belt 9 to form a toner image.

  The control unit 62 controls the motor 19 to convey the recording material and feed it to the secondary transfer unit T2. The secondary transfer unit T2 causes the toner image to be secondarily transferred and sent to the fixing device 8. The fixing device 8 is driven to fix the toner image on the recording material.

  The controller 62 controls the heater 8h of the fixing device 8 to maintain a high temperature necessary for fixing the toner image.

  The power control unit 63 controls the locking device 40 to restrict access to the door 32 so that fingers do not touch at least one of the toner image forming unit to which a high voltage is applied and the feeding mechanism in operation. To.

<Door member, locking device>
The door 31 is opened and closed when the toner cartridge 7a (7b, 7c, 7d: FIG. 3) for replenishing toner to the developing device 4a (4b, 4c, 4d: FIG. 3) is replaced. Since the door 31 is not provided with the lock mechanism 40 (see FIG. 2), the door 31 is not prevented from being opened during image formation. However, if the lifting of the door 31 is detected by a door switch (not shown), the image forming portion Pa, the high voltage generating portion 61, and the motor 18 are stopped after image formation is interrupted in the same manner as when the door 32 is opened. , 19 and the like are shut off.

  As shown in FIG. 4, the door 32 opens a part of the conveyance path of the recording material P when the recording material P is jammed or maintenance work is performed. The door switch 32s, which is an example of a door operation detection unit, detects an operation for opening the door 32, which is an example of a door member.

  As described above, when the lift of the door 32 is detected by the door switch 32s, the power supply to the image forming unit Pa, the high voltage generating unit 61, the motors 18, 19 and the like is interrupted after the image formation is interrupted. The

  The power switch 60 instructs to supply / shut off the power supply to the image forming apparatus 100 by being turned on and off. However, even if the power switch 60 is turned OFF, the power supply is not immediately interrupted, and after image formation is interrupted in the same manner as when the door 32 is opened, the image forming portion Pa, the high voltage generating portion 61, the power supply to the motors 18, 19, etc. is cut off.

  Thereby, when the doors 31 and 32 are opened during the image formation or the power switch 60 is turned off and an interruption command is output, the movable part remains in a state in which the recording material or toner image being processed does not remain. To shut off the high voltage. The locking device 40 restrains the door 32 for a short time until the recording material or toner image being processed does not remain, so that the safety of the work in the opened door 32 is ensured. . With the safety secured, the locking device 40 is released, and the door 32 can actually be opened.

<Control means>
FIG. 5 is a flowchart of the image formation interruption process.

  As shown in FIG. 5 with reference to FIG. 4, when the power switch 60 is turned ON and the switch 60 s is closed, the power control unit 63 operates the power relay 64 to supply power to each part of the image forming apparatus 100. Is started (S11).

  When the start switch 16 of the operation panel 15 is operated with the door 32 closed and the door switch 32s closed, the control unit 62 starts image formation control (S12). The same applies when an image forming job transmitted from the outside is received.

  At the start of image formation, the controller 62 confirms the number N of images to be formed (S13), operates the solenoid 46 (S14), and makes the door 32 unopenable by the locking device 40.

  The controller 62 starts feeding the recording material (S15) and starts image formation (S16).

  If the power switch 60 is not turned OFF (S17 is ON), the door 32 is not opened (NO in S18), and the stop switch 17 is not operated (NO in S19), the control unit 62 continues image formation (No in S19). Less than N of S20, S15 to S19).

  When the power switch 60 is turned off during image formation and the switch 60s is opened (S17 is OFF), the control unit 62 stops the new taking out of the recording material (S24).

  When the operation of opening the door 32 is performed during image formation and the door switch 32s is opened (YES in S18), the control unit 62 similarly stops the new taking out of the recording material (S24).

  In either case, the start of the formation of a new toner image in the image forming portion Pa or the like is stopped, but the toner image being formed is primarily transferred to the intermediate transfer belt 9 as usual. The toner image of the full color image formed on the intermediate transfer belt 9 is secondarily transferred to the last recording material fed to the secondary transfer portion T2 as usual, fixed by the fixing device 8, and discharged. In this way, the toner image being formed on the image forming portion Pa and the intermediate transfer belt 9 disappears, and image formation on the already taken out recording material is completed (S25).

  Thereafter, when the power supply control unit 63 turns off the solenoid 46 to release the locking device 40 (S26), the power supply relay 64 is turned off and the power supply to each unit of the image forming apparatus 100 is shut off (S27).

  When the stop switch 17 of the operation panel 15 is operated (YES in S19) or an instruction to cancel printing is received from the outside, the control unit 62 stops the new removal of the recording material (S21).

  When the number of fed sheets reaches the number N of formed images (N in S20), the control unit 62 stops the new taking out of the recording material (S21).

  In either case, the start of the formation of a new toner image in the image forming portion Pa or the like is stopped, but the toner image being formed is primarily transferred to the intermediate transfer belt 9 as usual. The toner image of the full color image formed on the intermediate transfer belt 9 is secondarily transferred to the last recording material fed to the secondary transfer portion T2 as usual, fixed by the fixing device 8, and discharged. In this way, the toner image being formed on the image forming portion Pa and the intermediate transfer belt 9 disappears, and image formation on the already taken out recording material is completed (S22).

  Thereafter, the power supply control unit 63 waits for the start of the next image formation or the restart of the remaining image formation with the locking device 40 released (S23). Since the locking device 40 is released at the end of the image forming job, the door 32 can be freely opened and closed without worrying about the locking device after the end of the image forming job.

  As described above, during the image formation, the image forming apparatus 100 operates the locking device 40 of the doors 32, 35, 36 to lock the doors 32, 35, 36 and move the doors 32, 35, 36. Prohibit opening.

  Even if the door 32 is opened during image formation, the locking device 40 prevents the door 32 from being opened, but soon the image formation being executed is completed and the locking device 40 is released to cut off the power supply. As a result, the toner image being formed and the recording material being conveyed are eliminated, and the inside of the door 32 can be accessed in a state where the movable portion is stopped and the application of the high voltage is also released.

  Also, if the power switch 60 is turned OFF by mistake during image formation, the power supply is continued, and similarly, the supply of power is cut off after the toner image being formed and the recording material being conveyed disappear. To do.

  Even if the door 32 is opened in these states, the image formation is completed and there is no recording material to be detected as jammed. Therefore, waste of the recording material and troublesome processing of the recording material can be prevented.

  Further, when the stop switch 17 is operated during image formation, the image forming job is interrupted after the toner image being formed or the recording material being conveyed disappears, and the locked state of the locking device 40 is released. Prepare for the restart of the remaining jobs. When the door 32 is opened in this state, the power control unit 63 immediately shuts off the power supply to each part of the image forming apparatus 100 and ensures the safety of access to the inside of the door 32.

  When the door 31 is opened to replenish toner, the power supply control unit 63 operates the locking device 40 to lock the door 32 and prohibits the door 32 from being opened. Make access to space impossible. As a result, image formation can be started without any problem when image formation is resumed.

  Further, when image formation is started while the door 31 is opened and the toner is replenished, the locking device 40 is operated to prohibit the door 32 from being opened and image formation is started. Therefore, even if the door 31 is opened. Image formation can be started.

  As described above, in the image forming apparatus 100, it is possible to prevent the waste of the recording material and the trouble of the jam processing even if the door 32 is opened or the power switch 60 is turned OFF during image formation.

It is explanatory drawing of the housing | casing structure of the image forming apparatus of 1st Embodiment. It is explanatory drawing of a structure of a locking device. FIG. 2 is an explanatory diagram of an internal configuration of the image forming apparatus according to the first embodiment. 2 is a block diagram of a control system of the image forming apparatus. FIG. 5 is a flowchart of image formation interruption processing.

Explanation of symbols

1a, 1b, 1c, 1d Photosensitive drums 4a, 4b, 4c, 4d Developing devices 7a, 7b, 7c, 7d Toner cartridge 8 Fixing devices 21, 22, 23, 11, 8 Feed mechanism (pickup roller, separation roller, resist) Roller, secondary transfer roller, fixing device)
31, 32, 35, 36 Door member (door)
32s Door operation detection means (door switch)
40 Locking device 60 Power switch 62, 63 Control means (control unit, power control unit)
100 Image forming apparatus P Recording materials Pa, Pb, Pc, Pd, 9 Toner image forming means (image forming unit, intermediate transfer belt)

Claims (4)

Toner image forming means for forming a toner image;
A feeding mechanism for feeding a recording material and transferring a toner image;
A fixing device for fixing the toner image by heating and pressing the recording material onto which the toner image has been transferred;
An image forming apparatus comprising: a door member capable of shielding at least one of the toner image forming unit and the feeding mechanism;
A locking device that fixes the closed door member to prevent opening;
Control means for releasing the locking device after completion of toner image formation by the toner image forming means and completion of fixing by the fixing device when an image formation interruption command is received. An image forming apparatus. A door operation detecting means for detecting an operation of opening the door member and generating the interruption command;
2. The control unit according to claim 1, wherein when the interruption command is received from the door operation detection unit, the control unit releases the locking device and shuts off the power of the toner image forming unit and the feeding mechanism. Image forming apparatus. A power switch for generating the interruption command when commanded to shut off power to the toner image forming means and the feeding mechanism;
3. The image forming apparatus according to claim 1, wherein the control unit releases the locking device and shuts off a power source of the toner image forming unit and the feeding mechanism. 4. The image forming apparatus according to claim 1, wherein the control unit fastens the locking device at the start of the image forming job and releases the locking device at the end of the image forming job.

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