JP2021165184A - Sheet feeding device and image forming device - Google Patents

Abstract

To provide an image forming device capable of performing more appropriately separating operation according to the state.SOLUTION: The image forming device includes: an opening/closing member capable of attaching and detaching feeding means by being opened; opening/closing detection means (702) for detecting opening and closing of the opening/closing member; service life determination means (704) for determining whether or not the feeding means reaches replacement life; and separation control means (706) for performing separating operation of moving the feeding means from a first position to a second position by moving means (35) according to detection of opening of the opening/closing member by the opening/closing detection means when the service life determination means determines that the feeding means reaches replacement life and not performing separating operation according to detection of opening of the opening/closing member by the opening/closing detection means when the service life determination means determines that the feeding means does not reach replacement life.SELECTED DRAWING: Figure 8

Description

The present invention relates to a sheet feeding device that feeds a sheet and an image forming device that forms an image on the sheet.

Image forming devices such as printers, copiers, and multifunction devices feed sheets loaded on trays or the like while separating them one by one by a feeding roller in order to feed sheets used as recording materials or originals. Equipped with a feeding device. The feeding roller may be configured to be movable by a drive source such as a motor or a solenoid to a position where the seat is in contact with the seat and a position where the seat is separated from the seat.

Further, since the surface of a roller involved in sheet transportation such as a feeding roller is gradually worn by repeating sheet transportation, it is necessary to perform regular roller replacement in order to maintain the performance. Patent Document 2 describes a configuration in which a separation roller that comes into contact with a feeding roller and a holder that holds the separation roller can be attached to and detached from the apparatus main body as one unit.

Japanese Unexamined Patent Publication No. 2008-037639

By the way, in the case of the configuration in which the feeding roller is moved by the power of the drive source, it is preferable to separate the feeding roller from the seat in advance so that the seat is not damaged when the feeding roller is replaced. However, for example, if the feed roller is configured to separate the feed roller whenever the door that enables access to the feed roller from outside the device is opened, the roller is separated even when the operator does not intend to replace the roller. The operation will be performed. This has the disadvantage that unnecessary operating noise is generated, and the life of the drive source is consumed by the originally unnecessary operation.

Therefore, an object of the present invention is to provide a sheet feeding device and an image forming device capable of performing a separation operation more appropriately depending on a situation.

In one aspect of the present invention, a seat support portion that supports a seat, a feeding means that feeds a sheet that is supported by the seat support portion, and the feeding means are supported by the seat support portion. A moving means that moves to a first position that comes into contact with the seat and a second position that is separated from the seat that is supported by the seat support portion, and a moving means that can be opened and closed and is opened to attach the feeding means. An opening / closing member that can be removed, an opening / closing detecting means for detecting the opening / closing of the opening / closing member, a life determining means for determining whether or not the feeding means has reached the replacement life, and the feeding means for replacement. When the life determining means determines that the life has been reached, the moving means moves the feeding means from the first position to the second position in response to the detection of the opening / closing member opening by the opening / closing detecting means. When the life-determining means determines that the feeding means has not reached the replacement life by executing the moving separation operation, the separation operation is performed in response to the detection of the opening / closing of the opening / closing member by the opening / closing detecting means. It is a sheet feeding device characterized by comprising a separation control means that does not execute.

In another aspect of the present invention, a seat support portion that supports the seat, a feeding means that feeds the seat that is supported by the seat supporting portion, and the feeding means that are supported by the seat support portion. A moving means for moving to a first position where the seat is in contact with the seat and a second position where the seat is separated from the seat supported by the seat support portion, and a feeding means which is provided so as to be openable and closable and opened to open. An opening / closing member that can be attached and detached, an opening / closing sensor that changes the detection signal according to the opening / closing of the opening / closing member, and detection according to the presence / absence of a seat at a detection position downstream of the feeding means in the sheet transport direction. The control means includes a seat sensor in which a signal changes and a control means for executing a separation operation of moving the feeding means from the first position to the second position by the moving means. When the frequency of the feeding operation exceeding the preset threshold value for the transport time from the start until the tip of the sheet reaches the detection position in the sheet transport direction is equal to or higher than the predetermined frequency, the opening / closing member is opened. When the separation operation is executed in response to a change in the detection signal of the opening / closing sensor and the frequency of occurrence of the feeding operation exceeding the threshold value is lower than the predetermined frequency, the opening / closing operation is performed by opening the opening / closing member. It is a sheet feeding device characterized in that the separation operation is not executed in response to a change in a detection signal of a sensor.

According to the present invention, it is possible to provide a sheet feeding device and an image forming device capable of performing a separation operation more appropriately depending on a situation.

The schematic diagram of the image forming apparatus which concerns on Example 1. FIG. The cross-sectional view of the sheet feeding part which concerns on Example 1. FIG. The figures (a to c) for demonstrating the removal of the feed roller unit and the separation roller unit which concerns on Example 1. FIG. It is a figure (a, b) for demonstrating the elevating structure of the lift plate which concerns on Example 1. FIG. It is a figure (a, b) for demonstrating the elevating structure of the feed roller which concerns on Example 1. FIG. It is a figure (a, b) for demonstrating the ascending / descending operation of a feed roller and a lift plate which concerns on Example 1. FIG. The block diagram which shows the hardware structure of the image forming apparatus which concerns on Example 1. FIG. The functional block diagram of the image forming apparatus which concerns on Example 1. FIG. The flowchart (a, b) which shows the control method of the image forming apparatus which concerns on Example 1. FIG. FIG. 3 is a perspective view showing a mechanism for moving the lift plate and the feeding roller according to the second embodiment. The functional block diagram of the image forming apparatus which concerns on Example 2. FIG. The flowchart which shows the control method of the image forming apparatus which concerns on Example 2.

Hereinafter, exemplary embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing an image forming apparatus 1 according to the first embodiment. The image forming apparatus 1 is an electrophotographic laser beam printer that forms a monochrome toner image. The image forming apparatus 1 has a sheet feeding section 2 for feeding the sheet S used as a recording material, and an image forming section 5 for forming an image on the sheet. The size and material of the recording material include paper such as plain paper and cardboard, sheet material with surface treatment such as plastic film, cloth, and coated paper, and sheet material having a special shape such as envelope and index paper. A variety of different sheets can be used.

The image forming unit 5 includes a process cartridge P, a laser scanner 52, and a transfer roller 53. When a command for image formation is input to the image forming apparatus 1, the image forming unit 5 starts an image forming operation by an electrophotographic process. That is, the photosensitive drum 51 provided on the process cartridge P starts rotating, and the charger uniformly charges the drum surface. Based on the image information input to the image forming apparatus 1, the laser scanner 52 irradiates the photosensitive drum 51 with a laser beam for exposure, and writes an electrostatic latent image on the drum surface. This latent image is developed by a developer supplied from a developing device, and a toner image is formed on the photosensitive drum 51.

In parallel with this process, the sheet S is fed from the sheet feeding unit 2. The seat feeding unit 2 includes a feeding roller 211 that feeds the seat S loaded on the lift plate 31 as the seat supporting portion provided on the cassette 3. The cassette 3 can be pulled out from the device main body 1A of the image forming apparatus 1 in the pull-out direction E2, and is attached to the device main body 1A by being inserted in the insertion direction E1. The sheet S fed by the sheet feeding unit 2 is conveyed to the transfer unit, which is the nip portion between the photosensitive drum 51 and the transfer roller 53, via the transfer roller pair 4. In the transfer section, a bias voltage having a polarity opposite to the normal charging polarity of the toner is applied to the transfer roller 53, so that the toner image supported on the photosensitive drum 51 is transferred to the sheet S.

The fixing portion 6 forms a fixing nip by a heating unit 61 composed of a fixing film and a ceramic heater or the like as a heating means arranged on the inner peripheral side of the fixing film, and a pressure roller 62 that is in pressure contact with the heating unit 61. .. When the sheet S passes through the fixing nip, the toner image on the sheet is heated and pressurized to melt the toner, and then the toner is fixed, so that the unfixed image is permanently fixed to the sheet S. The sheet S that has passed through the fixing portion 6 is discharged to the outside of the machine by the discharge roller pair 8 via the discharge path 7, and is loaded on the discharge tray 9.

Further, the image forming apparatus 1 is provided with an operation unit 75 that serves as a user interface. The operation unit 75 includes a display device such as a liquid crystal panel that displays information to the user. It also includes an input device that accepts input operations from the user, such as physical keys such as an OK button and a numeric keypad, and a touch panel function of a liquid crystal panel.

Further, the image forming apparatus 1 has sheet sensors (76, 77, 78) at a plurality of positions along the transfer path of the sheet S as a means for monitoring the transfer of the sheet S and detecting the occurrence of jam. Have been placed. The registration sensor (hereinafter referred to as the registration sensor 76) detects the sheet S at the detection position between the transfer roller pair 4 and the transfer unit. The fixing discharge sensor 77 detects the sheet S at a detection position between the fixing portion 6 and the discharge roller pair 8. The discharge sensor 78 detects the sheet S at a position near the downstream side of the discharge roller pair 8. These seat sensors are configured so that the detection signal changes depending on the presence or absence of the seat at the detection position. As an example of the seat sensor, a flag type sensor including a flag that protrudes toward the transport path and is pressed by the seat and swings, and a photointerruptor that detects the swing of the flag can be used. The above-mentioned sheet sensor functions as a sheet detecting means for detecting the arrival of the sheet at the detection position.

As will be described later, in the CPU circuit 603 (FIGS. 7 and 8) of the image forming apparatus 1, a transfer abnormality such as a jam occurs during the transfer of the sheet S based on the detection signal of the seat sensor (76, 77, 78). Determine if it has occurred. The jam refers to a state in which the transfer operation of the sheet S needs to be stopped because the transfer operation of the sheet S is delayed beyond the permissible range for normal image formation. For example, if the tip of the sheet S has not reached the registration sensor 76 even after a predetermined time has elapsed from the start of the feeding operation, the printer control unit 600 determines that a jam has occurred. When a transport abnormality occurs, the printer control unit 600 causes the operation unit 75 to display a notification that the transport abnormality has occurred, and, if necessary, display a display instructing an operation for eliminating the transport abnormality.

The detection signals of the registration sensor 76, the fixing discharge sensor 77, and the discharge sensor 78 change when either the front end or the rear end of the sheet S passes through. Therefore, the printer control unit 600 calculates the size of the sheet S based on the detection result of the registration sensor 76, or the tip of the sheet S reaches the detection position of the registration sensor 76 from the reference time point (for example, at the start of the feeding operation). It is possible to calculate the elapsed time (transportation time) until the printer is used. By calculating the sheet size, if the preset sheet size and the size of the sheet S detected by the registration sensor 76 are different, it is possible to detect a transport abnormality such as a sheet size mismatch. In the present embodiment, the jam is treated as a typical example of the transport abnormality, but the above-mentioned sheet size mismatch, the one-sided transport in which the sheet S is biased to one of the width directions, and the sheet S are tilted and transported. The skew may also be treated as a transport abnormality. Further, a state in which the seat S is clearly delayed compared to the normal transfer operation may be treated as a transfer delay, which is a kind of transfer abnormality, even if it does not cause a jam.

In this embodiment, the image forming unit 5, which is a direct transfer type electrophotographic unit, is used as the image forming means for forming an image on the sheet. However, the present invention is not limited to this, and an intermediate transfer type electrophotographic unit that transfers a toner image formed on a photoconductor to a sheet via an intermediate transfer body such as an intermediate transfer belt may be used as an image forming means. Further, the present invention is not limited to this, and for example, an inkjet type image forming unit that forms an image on a sheet by ejecting an ink liquid from a nozzle may be used as an image forming means.

[Sheet feeding section]
The detailed configuration of the seat feeding unit 2 which is the seat feeding device in this embodiment will be described with reference to FIG. FIG. 2 shows a cross section of the sheet feeding section 2 as seen from the width direction of the sheet fed by the sheet feeding section 2 (direction orthogonal to the feeding direction, main scanning direction at the time of image formation). be.

The sheet feeding unit 2 includes a feeding frame 22, a feeding roller unit 21, and a separation roller unit 24A. The feeding frame 22 is fixed to the frame of the image forming apparatus, constitutes a part of the apparatus main body 1A of the image forming apparatus, and constitutes the frame of the sheet feeding device in the present embodiment. There is. However, the apparatus main body 1A refers to a portion of the image forming apparatus 1 excluding the cassette 3, the access door 70, the feeding roller unit 21 and the separating roller unit 24A, and is a frame such as the feeding frame 22 or an image forming apparatus. Includes 1 exterior member. The feeding roller unit 21 and the separating roller unit 24A are detachably supported by the feeding frame 22. The cassette 3 is openable and closable with respect to the main body of the image forming apparatus, that is, is movable with respect to the feeding frame 22, and is configured to be detected by the cassette open / close sensor 74 (FIGS. 7 and 8). ..

The feed roller unit 21 is a unit including a feed roller 211, a transport roller 212, a roller holder 213, and a gear train 214. The feeding roller 211 and the transport roller 212 are rotatably held by a roller holder 213 as a holding member. The roller holder 213 can swing about the rotation axis of the transport roller 212. A pressurizing mechanism using a spring member as an example is connected to the roller holder 213 in order to apply a pressing force to the seat by urging the feeding roller 211 downward.

The feed roller 211 as a feed member is driven by a feed motor, which will be described later, as a drive source, and rotates counterclockwise in the drawing to load a seat loaded on a lift plate 31 as a seat load portion. Send out in the feeding direction (right side in the figure). The transport roller 212 is also driven by a feed motor, which is a common drive source, to rotate counterclockwise in the drawing, and further transports the sheet toward the downstream in the feed direction. The gear train 214 includes an input gear coaxial with the transfer roller 212 provided on the apparatus main body 1A and meshing with the drive gear connected to the feed motor, and a transmission gear that transmits the rotation of the input gear to the feed roller 211. including. The driving force supplied from the feed motor is transmitted to the feed rollers 211 and the transport rollers 212 via the gear train 214 to rotate each roller.

The separation roller unit 24A is a unit having a separation roller 24 as a separation member. The separation roller 24 is a roller member connected to a fixed shaft via a torque limiter. The separation roller 24 abuts on the transport roller 212 to form a separation nip, and separates the sheet passing through the separation nip by frictional force. That is, when only one sheet fed by the feeding roller 211 has passed through the separation nip, the torque limiter slides and the separation roller 24 is carried around to the transport roller 212 via the sheet. On the other hand, when a plurality of sheets enter the separation nip, the separation roller 24 stops rotating and slides the sheets together, and only the uppermost sheet in contact with the transfer roller 212 is conveyed. Such a separation roller 24 is an example of a separation member, and is a retard roller in which a driving force in a direction opposite to the sheet feed (counterclockwise direction in the drawing) is input from the feed motor, or a pad in contact with the transport roller 212. A shaped friction member may be used.

In the seat feeding unit 2, the upper surface of the sheet loaded on the lift plate 31 (the upper surface of the uppermost sheet) has an appropriate height for feeding by the feeding roller 211 (hereinafter referred to as a feeding position). ) Is installed, and the feed position sensor 215 whose detection signal changes depending on whether or not the signal is present is installed. The feed position sensor 215 is a detection means for detecting the position of the roller holder 213, and in this embodiment, a photo interrupter that is shielded by a detection unit 213a (light-shielding unit) provided on the roller holder 213 is used. When the detection unit 213a is on the optical axis of the feed position sensor 215, it is determined that the upper surface of the sheet loaded on the lift plate 31 is in the feed position, and when not, the upper surface of the sheet is from the feed position. It is judged to be either above or below.

As will be described later, when the seat feeding unit 2 starts the feeding operation, the feeding roller 211 descends from the upper position above the feeding position and once moves to the lower position below the feeding position. do. In this state, when the upper surface of the sheet comes into contact with the feeding roller 211 due to the lift-up of the lift plate 31, the roller holder 213 is lifted against the urging force of the pressurizing mechanism. Then, when the feed position sensor 215 detects the detection unit 213a, the lift-up of the lift plate 31 is stopped. If the lift plate 31 is lifted up while the sheet is not loaded on the lift plate 31, the lift plate itself comes into contact with the feeding roller 211.

The sheet is fed from the cassette 3 by the feeding motor rotating the feeding roller 211 and the transport roller 212 in a state where the feeding roller 211 is in contact with the sheet at the feeding position. Further, the sheets are transferred to the transfer roller pair 4 in a state of being separated one by one by the transfer roller 212 and the separation roller 24. As the number of sheets loaded on the lift plate 31 decreases due to the repeated feeding of the sheets, the position of the feeding roller 211 gradually lowers. When the detection unit 213a of the roller holder 213 moves to a position not detected by the feed position sensor 215, the lift motor 35 raises the lift plate 31 again until the feed position sensor 215 detects the detection unit 213a again. As a result, the upper surface of the seat loaded on the lift plate 31 is always controlled within a certain range.

[Access door]
As shown in FIG. 1, the image forming apparatus 1 is provided with an access door 70 as an opening / closing member. The access door 70 is configured to be openable and closable with respect to the device main body 1A by being rotatably supported by the device main body 1A via a hinge provided below the access door 70. As shown in FIG. 1, when the access door 70 is closed (closed state), the access door 70 constitutes a part of the side surface of the image forming apparatus 1, and the image forming apparatus 1 is in a state where the image forming operation can be executed. Become.

When the access door 70 is opened as shown in FIG. 3A, at least a part of the transport path of the seat S in the image forming apparatus 1 is opened. When a jam occurs, the user can easily remove the sheet that caused the jam by opening the access door 70 as shown in FIG. 3A according to the display of the operation unit 75. The access door 70 of this embodiment is provided on the side surface of the device main body 1A on the side opposite to the side where the cassette 3 is pulled out from the device main body 1A, and is opened in the direction (E1) opposite to the pull-out direction E2 of the cassette 3. In each of the drawings of FIG. 3, the access door 70 connected to the device main body 1A via the hinge is schematically shown in a state of being separated from the device main body 1A, but the access door 70 is shown in the device main body 1A. It may be a detachable configuration.

Further, the seat feeding unit 2 in this embodiment is configured so that the feeding roller unit 21 and the separation roller unit 24A can be attached and detached by opening the access door 70. That is, when the access door 70 is opened as shown in FIG. 3A, the separation roller unit 24A is exposed to the outside of the device main body 1A. In this state, the user can remove the separation roller unit 24A from the device main body 1A as shown in FIG. 3B by grasping the separation roller unit 24A and pulling it out in the removal direction R (see also FIG. 2). ..

When the separation roller unit 24A is removed, the feeding roller unit 21 is exposed when viewed from the downstream side in the removal direction R. In this state, the user can remove the feeding roller unit 21 from the device main body 1A as shown in FIG. 3C by grasping the feeding roller unit 21 and pulling it out in the removal direction R. Then, by attaching and detaching the feeding roller 211 and the transport roller 212 to and from the roller holder 213 described above, the old roller can be replaced with a new roller.

When the feeding roller unit 21 and the separating roller unit 24A are mounted on the apparatus main body 1A, the above procedure may be reversed. That is, in the state shown in FIG. 3C, the user grasps the feeding roller unit 21 and moves it in the direction opposite to the removal direction R, so that the feeding roller unit 21 is moved to a predetermined mounting position of the device main body 1A. Attach to. Further, the user attaches the separation roller unit 24A to the apparatus main body 1A by grasping the separation roller unit 24A and moving it in the direction opposite to the removal direction R. Then, by closing the access door 70, the user ends the mounting procedure of the feeding roller unit 21 and the separation roller unit 24A.

The mounting position of the feed roller unit 21 means that the feed motor rotates the feed roller 211 and the transport roller 212 by engaging the input gear of the gear row 214 with the drive gear of the apparatus main body 1A. Refers to a possible position. Further, when the feeding roller unit 21 is in the mounting position, the feeding roller unit 21 can swing about the support shaft by engaging the roller holder 213 with the support shaft provided on the feeding frame 22. It becomes a state.

Further, in this embodiment, the separation roller unit 24A is always removed when the feeding roller unit 21 is removed, but if a space for attachment / detachment can be secured, the separation roller unit 24A is still attached and fed. The roller unit 21 may be attached / detached.

[Raising and lowering the lift plate]
Next, the elevating mechanism provided in the cassette 3 will be described with reference to FIGS. 4 (a and 4). FIG. 4A and 4B are perspective views showing a schematic configuration of the elevating mechanism 30 of this embodiment. FIG. 4A shows an initial state in which the lift plate 31 is in the initial position, and FIG. 4B shows a lift-up state in which the lift plate 31 is above the initial position.

As shown in FIG. 4A, the elevating mechanism 30 includes a lift member 32, a lift input gear 34, and a lift output gear 33. The lift member 32 is arranged between the bottom of the cassette 3 and the lift plate 31, is rotatably supported by the cassette 3, and is rotated to raise and lower the lift plate 31. The lift output gear 33 is a fan-shaped gear that rotates integrally with the lift member 32, and meshes with the lift input gear 34. The lift input gear 34 is connected to the lift motor 35, which is a drive source, via a reduction gear train 38, and is rotated by the driving force of the lift motor 35.

Among the elevating mechanisms 30, the reduction gear train 38 also constitutes a transmission unit that transmits the driving force of the lift motor 35 to the roller elevating unit 30B, which will be described later. The lift output gear 33, the lift input gear 34, and the lift member 32 operate by receiving a driving force from the transmission unit to form a lift plate elevating unit 30A (first elevating unit of this embodiment) that elevates and elevates the lift plate 31. doing.

The lift motor 35 is a drive motor capable of outputting rotation in the first direction and vice versa based on a command signal from a control circuit described later. Hereinafter, the rotation direction (first direction in this embodiment) of the lift motor 35 when the lift member 32 is raised to lift up the lift plate 31 is referred to as a “forward rotation direction”. On the contrary, the rotation direction (second direction in this embodiment) of the lift motor 35 when the lift member 32 is lowered to lift down the lift plate 31 is defined as the "reverse direction".

The lift member 32 and the lift output gear 33 are supported by the cassette 3, and the lift input gear 34 and the reduction gear train 38 are supported by the frame of the image forming apparatus together with the lift motor 35. Therefore, when the cassette 3 is pulled out in the width direction W (direction perpendicular to the feeding direction Fd) of the seat in FIGS. 4 (a, b), the lift output gear 33 and the lift input gear 34 are disengaged. When the cassette 3 is inserted into the image forming apparatus to the predetermined mounting position shown in FIGS. 4A and 4B, the lift output gear 33 and the lift input gear 34 mesh with each other, and the lift member 32 is the lift motor 35. Is always connected to. Therefore, in this embodiment, the lift motor 35 can both lift up and down the lift plate 31 while the cassette 3 is closed.

Further, the reduction gear train 38 includes a worm gear 38a and a plurality of stage gears 38b and 38c (see also FIG. 4), and reduces the rotation of the lift motor 35 to a large diameter gear 38d integrated with the lift input gear 34. introduce. Therefore, even if a small motor having a relatively small output torque is used as the lift motor 35, the lift plate 31 (and the feeding roller 211 as described later) can be stably lifted and lowered.

[Feeding roller lifting mechanism]
Next, a roller elevating portion 30B (second elevating portion of this embodiment), which is a mechanism for elevating and lowering the feed roller 211 by using the driving force of the lift motor 35, will be described with reference to FIG. The roller elevating part 30B is interposed between the lift motor 35 and the feeding roller unit 21 in a form of connecting the reduction gear train 38 as the transmission part and the roller holder 213. The roller elevating unit 30B is a device (feeding roller unit 21) that moves the feeding roller unit 21 so that the feeding roller 211 abuts and separates from the seat by swinging the roller holder 213 using the driving force of the lift motor 35. Feed roller contact separation part). The lifting mechanism 30 and the lift motor 35 move the feeding roller unit 21 to a first position for feeding the seat in contact with the seat and a second position away from the seat. Functions as.

The roller elevating portion 30B is composed of a roller elevating gear 36, a roller elevating link 37, and a roller elevating lever 25. The roller lift gear 36 is connected to the lift motor 35 via a reduction gear train 38. The roller elevating lever 25 is a swing member that is connected to the feed roller unit 21 and swings in conjunction with the feed roller unit 21. The roller elevating link 37 has a rack portion 37a that meshes with the roller elevating gear 36, and is a link member that connects the roller elevating gear 36 and the roller elevating lever 25.

The roller elevating link 37 and the roller elevating lever 25 are movably supported by the feeding frame 22. The roller elevating link 37 can slide and move in the vertical direction (substantially vertical direction), and converts the rotation of the roller elevating gear 36 that meshes with the rack portion 37a into a linear motion in the vertical direction. The forward rotation of the lift motor 35 lowers the roller elevating link 37, and the reverse rotation of the lift motor 35 raises the roller elevating link 37.

The roller elevating lever 25 is a swing member that can swing up and down about a swing shaft extending in the direction of the rotation axis of the feed roller 211 (the width direction of the seat). The roller elevating lever 25 is engaged with the roller holder 213 of the feeding roller unit 21 at one end 25a in the axial direction, and swings up and down together with the roller holder 213. The other end portion 25b of the roller elevating lever 25 in the axial direction faces the pressing portion 37b provided at the upper end of the roller elevating link 37. At the engagement point between the pressing portion 37b and the end portion 25b of the roller elevating lever 25, the roller holder 213 and the roller elevating lever 25 are held in a state where the roller elevating link 37 is stopped by pressing the feeding roller 211 against the seat. It is configured to allow it to swing upwards. Further, a pressure spring as an urging means is attached between the roller elevating lever 25 and the feeding frame 22, and the roller elevating lever 25 is urged downward.

When the roller elevating link 37 is lowered by the forward rotation of the lift motor 35, the roller elevating lever 25 rotates downward due to the urging force and its own weight of the pressure spring. When the roller elevating link 37 rises due to the reversal of the lift motor 35, the roller elevating lever 25 swings upward by being pressed by the pressing portion 37b of the roller elevating link 37.

Further, the feed roller unit 21 is detachably attached to the feed frame 22, and the engagement portion (connection portion) between the feed roller unit 21 and the roller elevating lever 25 is also detachable. The engaging portion is configured so that the end portion 25a of the roller elevating lever 25 fits into the hook portion 213b provided on the roller holder 213.

The feed roller unit 21 can be removed from the feed frame 22 in a predetermined removal direction R (direction intersecting the axial direction of the swing axis of the roller elevating lever 25) that intersects the rotation axis of the feed roller 211. be. In accordance with this, the hook portion 213b is configured to have a concave shape in which the upstream side in the removal direction R is open, and the end portion 25a of the roller elevating lever 25 is separated from the hook portion 213b as the feeding roller unit 21 is removed. do. When the feeding roller unit 21 is attached to the feeding frame 22 in the direction opposite to the removal direction R, the end portion 25a of the roller lifting lever 25 is fitted into the hook portion 213b accordingly, and the roller lifting lever is fitted. The 25 and the roller holder 213 are in a state of swinging integrally.

Here, the seat feeding unit 2 is an interlocking unit that moves the feeding roller unit 21 in conjunction with the drawer of the cassette 3 in addition to the above-mentioned mechanism for raising and lowering the feeding roller unit 21 by the driving force of the lift motor 35. The release lever 39 is provided. The release lever 39 can be rotated about the rotation shaft 39a by the feeding frame 22, and is for moving the pressed portion 39b pressed by the pressing portion provided on the cassette 3 and the feeding roller unit 21. It has a working portion 39c and. Further, the release lever 39 is urged in a rotation direction (arrow U) in which the pressed portion 39b moves in the direction opposite to the insertion direction E1 of the cassette 3 by a torsion coil spring (not shown) which is an urging member. ..

When the cassette 3 is mounted on the apparatus main body 1A, the release lever 39 is held at the position shown in FIG. 5A by pressing the pressed portion 39b of the release lever 39 in the insertion direction E1 by the cassette 3. NS. In this state, the feed roller unit 21 can move up and down via the roller elevating unit 30B in response to the forward rotation and reverse rotation of the lift motor 35.

On the other hand, when the cassette 3 is pulled out from the apparatus main body 1A, the release lever 39 released from the pressing portion of the cassette 3 rotates in the direction of the arrow U by the restoring force of the torsion coil spring, and the position shown in FIG. 5 (b). Move to. Along with this, the operating portion 39c of the release lever 39 pushes up the roller elevating lever 25 in the direction of arrow Z, so that the feeding roller unit 21 rotates upward (arrow C2).

[Operation of lifting mechanism]
Subsequently, the lifting operation of the lift plate 31 and the feeding roller 211 by the lifting mechanism 30 in this embodiment will be described with reference to FIG. FIG. 6A shows a state in which the feeding roller 211 is in contact with the sheet on the lift plate 31 as viewed from the direction of the rotation axis of the feeding roller 211 (the width direction of the sheet) (hereinafter, the feeding roller contact state). It is a schematic diagram which shows. FIG. 6B is a schematic view showing a state in which the feeding roller 211 is separated from the seat on the lift plate 31 (hereinafter referred to as a feeding roller separated state) as viewed from the direction of the rotation axis of the feeding roller 211. be. The position of the feeding roller unit 21 in the feeding roller contact state is the first position of this embodiment, and the position of the feeding roller unit 21 in the feeding roller separated state is the second position of this embodiment.

As shown in FIG. 6A, the lift motor 35 rotates in the normal direction in the operation (contact operation) for shifting from the feed roller separated state to the feed roller contact state. As a result, the elevating mechanism 30 performs an operation of lowering the feed roller 211 by the roller elevating portion 30B and raising the lift plate 31 by the lift plate elevating portion 30A. That is, the roller elevating link 37 is lowered by the forward rotation of the lift motor 35 (arrow A1), and the roller elevating lever 25 is rotated downward (arrow B1) accordingly, and is further fed in conjunction with the roller elevating lever 25. The roller unit 21 rotates downward (arrow C1). In parallel with this, the lift member 32 rotates upward due to the normal rotation of the lift motor 35, and the lift plate 31 is lifted up (arrow D1). As described above, when the feeding position sensor 215 detects the detection unit 213a of the roller holder 213, the lift-up of the lift plate 31 is stopped, and the feeding roller contact state is realized.

On the other hand, as shown in FIG. 6B, the lift motor 35 reverses in the operation (separation operation) for shifting from the feeding roller contact state to the feeding roller separating state. As a result, the elevating mechanism 30 performs an operation of raising the feed roller 211 by the roller elevating portion 30B and lowering the lift plate 31 by the lift plate elevating portion 30A. That is, the roller elevating link 37 rises due to the reversal of the lift motor 35 (arrow A2), the roller elevating lever 25 rotates upward (arrow B2), and the feeding roller is further linked to the roller elevating lever 25. The unit 21 rotates upward (arrow C2). In parallel with this, the lift member 32 rotates downward due to the reversal of the lift motor 35, and the lift plate 31 is lifted down (arrow D2). As a result, the feeding roller separated state is realized.

When the cassette 3 is pulled out from the apparatus main body 1A in the feeding roller contact state shown in FIG. 6A, the roller lifting lever 25 is pushed up by the operation of the release lever 39 described above, and the feeding roller 211 is shown by the broken line. It is separated from the upper surface of the sheet S so as to be separated from the upper surface of the sheet S.

[hardware]
FIG. 7 is a block diagram showing a hardware configuration of the image forming apparatus 1 according to the present embodiment. The printer control unit 600 includes circuits such as a CPU 603, a ROM 604, a RAM 605, and a video interface 620, and executes a program for controlling each device in the image forming device 1. The CPU CPU 603 reads the program stored in the ROM 604 and executes the program using the RAM 605 as a work area to control each unit in the image forming apparatus 1 such as the sheet feeding unit 2 as described below. The ROM 604 and the RAM 605 are examples of non-transient storage media that can be read by a computer that stores a program for controlling a sheet feeding device and an image forming device.

The controller 602 is connected to the printer control unit 600 via the video interface 620, and is connected to an information device such as the host computer 601 via a network, a printer cable, or the like. When the controller 602 receives an execution instruction (print instruction) of the image forming operation from the host computer 601, the controller 602 causes the printer control unit 600 to execute the image forming operation according to the setting information included in the print instruction. Specifically, the controller 602 transmits an image formation reservation command to the printer control unit 600, and then transmits an image formation start command to the printer control unit 600 at the timing when the image formation is possible.

The controller 602 and the operation unit 75 can communicate with each other. The controller 602 sets the image formation conditions according to the image formation mode specified by the operation unit 75. Further, when the printer control unit 600 detects the occurrence of a transfer abnormality such as a sheet jam, the operation unit 75 displays a message indicating the occurrence of the transfer abnormality and the coping method based on the instruction from the printer control unit 600. ..

The printer control unit 600 prepares for execution of image formation in the order of the image formation reservation command from the controller 602, and waits for the image formation start command from the controller 602. Upon receiving the image formation start command, the printer control unit 600 outputs a TOP signal, which is a reference timing for outputting the video signal, to the controller 602, and starts the image formation operation according to the content of the image formation reservation command. Next, each actuator connected to the CPU 603 will be described.

The feed motor drive circuit 607 and the lift motor drive circuit 608 are connected to the CPU 603 via the IO port 606. Further, the door open / close sensor input circuit 609, the cassette insertion / removal sensor input circuit 610, the registration sensor input circuit 611, the fixing / discharging sensor input circuit 612, and the discharging sensor input circuit 613 are connected to the CPU 603 via the IO port 606.

The feed motor drive circuit 607 is a circuit that supplies power to the feed motor 621 to drive it. When the feed motor 621 is driven, the feed rollers 211 and the transport rollers 212 of the feed roller unit 21 are rotationally driven in the rotational direction for feeding the sheet in the sheet transport direction.

The lift motor drive circuit 608 is a circuit that supplies electric power to the lift motor 35 to drive the lift motor 35. As described above, when the lift motor 35 is rotationally driven in the forward rotation direction, the lift plate 31 in the cassette 3 rises and the feed roller 211 lowers. Further, when the lift motor 35 is rotationally driven in the reverse direction, the lift plate 31 is lowered and the feeding roller 211 is raised.

The door open / close sensor input circuit 609 inputs information indicating whether the access door 70 as an open / close member is in the open state or the closed state to the CPU 603 based on the change in the detection signal of the door open / close sensor 615 which is the open / close sensor of this embodiment. do. The cassette insertion / removal sensor input circuit 610 inputs information on whether the cassette 3 is inserted or removed to the CPU 603 based on the change in the detection signal of the cassette insertion / removal sensor 616. The registration sensor input circuit 611 inputs information on whether or not there is a sheet at the detection position of the registration sensor 76 to the CPU 603 based on the change in the detection signal of the registration sensor 76. Similarly, the fixing / discharging sensor input circuit 612 and the discharging sensor input circuit 613 also input information on whether or not the sheet S is present at the detection positions of the fixing / discharging sensor 77 and the discharging sensor 78 to the CPU 603.

(Control system of image forming device)
FIG. 8 is a functional block diagram showing a control system of the image forming apparatus 1 realized by the hardware of FIG. 7. The image forming apparatus control means 700 as the controlling means of this embodiment for controlling the image forming apparatus 1 is realized by the control circuit of the printer control unit 600. The control circuit of the printer control unit 600 is composed of a CPU 603, a ROM 604 that stores a control program, a RAM 605 that stores data and the like, a gate element, and the like.

The image forming apparatus control means 700 includes the following elements.
-Cassette insertion / removal detection unit 701 that determines the insertion / removal state of the cassette 3 based on the detection result of the cassette insertion / removal sensor 616.
-The door open / close detection unit 702 (open / close detection means of this embodiment) that determines the open / closed state of the access door 70 based on the detection result of the door open / close sensor 615.
A feed control unit 703 that controls the feed of the seat S by driving the feed motor 614.
The feed roller 211 has reached the replacement life based on the time (transport time T) from when the feed control unit 703 starts executing the feed operation until the register sensor 76 detects the tip of the sheet S. Roller life estimation unit 704 (life determination means of this embodiment) for estimating whether or not there is a roller life.
A transport abnormality determination unit 705 (transport abnormality detecting means of this embodiment) that determines the occurrence of a transport abnormality based on the detection results of the registration sensor 76, the fixing discharge sensor 77, and the discharge sensor 78.
The insertion / removal state of the cassette 3 detected by the cassette insertion / removal detection unit 701, the open / closed state of the access door 70 detected by the door open / close detection unit 702, the estimation result of the roller life estimation unit 704, and the determination result of the transport abnormality determination unit 705. Based on the above, the feed roller separation determination unit 706 (the separation control means of this embodiment) determines whether or not to execute the separation operation of the feed roller 211 when the access door 70 is opened.
-A replacement procedure display unit 707 that displays a procedure for replacing the feed roller 211 on the operation unit 75 when the feed roller separation determination unit 706 determines that the separation operation of the feed roller 211 is not executed.

The roller life estimation unit 704 measures the number of feeding operations C until the feeding operation in which the transport time T exceeds the preset threshold time Th1 (threshold value) and the next feeding operation in which the threshold time Th1 is exceeded. Record in a buffer prepared in a non-volatile memory (not shown). Then, the average value Cave of the past 10 feeding operation times C is calculated, and if the Cave is less than or equal to the threshold value Th2, it is determined that the feeding roller 211 has reached the end of its life, and if it exceeds the threshold value Th2, it is determined. It is determined that the life has not been reached. The fact that the Cave is less than or equal to the threshold value Th2 means that the transport efficiency of the feed roller 211 (the actual amount of movement of the sheet with respect to the rotation amount) has decreased due to wear of the feed roller 211 or the like, so that the sheet is fed at a predetermined frequency. This is because it is considered that the delivery delay occurs with the above frequency. The delivery delay referred to here means that the transportation of the sheet S is delayed to the extent that it is considered that a jam will occur in a relatively near future if it is left unattended, although it is not determined to be a jam. The threshold time Th1 is set for each level of the transport speed (process speed of the image forming unit 5) as shown in Table 1, for example. Further, the threshold value Th2 is set to, for example, 670 times, and in this case, the predetermined frequency represents "the frequency of once per 670 feeding operations on average".

Further, the transport abnormality determination unit 705 measures the registration sensor arrival time Treg from the start of the feeding operation to the detection of the tip of the sheet S by the registration sensor 76. When the registration sensor arrival time Treg is slower than the threshold time Th3, the transport abnormality determination unit 705 determines that a jam has occurred and urgently stops the image forming apparatus. Th3 is set for each transport speed as shown in Table 2. Similarly, the transport abnormality determination unit 705 also measures the arrival time until the tip of the sheet S is detected in the fixing discharge sensor 77 and the discharge sensor 78, and determines whether or not a jam has occurred based on the arrival time. do. The jam determination threshold time Th3 in the register sensor 76 is longer than the threshold time Th1 for determining the feed delay using the register sensor 76.

FIG. 9A shows a flowchart of the process performed by the feed roller separation determination unit 706, which is started when the door open / close detection unit 702 detects that the access door 70 has been opened.

In S101, the cassette insertion / removal detection unit 701 confirms from the determination result whether the cassette 3 is inserted at the mounting position of the apparatus main body 1A. Then, when the cassette 3 is inserted, the process proceeds to S102, and when the cassette 3 is pulled out, it is determined that the feeding roller 211 is already separated, and the process proceeds to S109, and the separation determination is "not separated". And end the process.

In S102, the determination result of the roller life estimation unit 704 is confirmed, and if it is determined that the feeding roller 211 has reached the end of its life, the process proceeds to S103. It is judged that the possibility of replacing the feed roller 211 is low, and the process proceeds to S105.

In S103, it is confirmed from the determination result of the transport abnormality determination unit 705 whether or not a jam has occurred. Then, if no jam has occurred, the process proceeds to S104, and the separation determination is determined to "separate operation" to end the process. If a jam occurs at any part of the transport path, the jam process is performed. Therefore, it is determined that the access door 70 has been opened, and the process proceeds to S105.

In S105, the separation determination is determined to "do not separate", the processing of the replacement procedure display unit 707 described later in S106 is started, and the processing of the feeding roller separation determination is completed.

FIG. 8B is a process performed by the replacement procedure display unit 707, which is started in S106 of the flowchart shown in FIG. 8A. S111 displays information on the operation unit 75 that the cassette 3 needs to be pulled out in order to replace the feeding roller 211, and proceeds to S112. For example, the replacement procedure display unit 707 prompts the user to operate by displaying a text message on the liquid crystal panel of the operation unit 75 stating that the cassette 3 needs to be pulled out in order to replace the feeding roller 211.

In S112, the door open / close detection unit 702 waits until the access door 70 is closed, or the cassette insertion / removal detection unit 701 detects that the cassette 3 has been pulled out, and when either of them is detected, the process proceeds to S113. .. In S113, the replacement procedure display on the operation unit 75 ends, and the process ends.

In this embodiment, if the feed roller 211 has not reached the replacement life when the access door 70 is opened, it is unlikely that the feed roller separation determination unit 706 will replace the feed roller 211. It is determined that the separation operation is not performed (S102, S105). On the other hand, when the access door 70 is opened when the feed roller 211 has reached the replacement life, the feed roller separation determination unit 706 determines that the feed roller 211 is relatively likely to be replaced. Then, the separation operation is performed (S102, S104). In this way, by performing the separation operation more appropriately according to the situation regarding the state of the feed roller 211, the number of cases where the separation operation is performed unnecessarily is reduced, the operating noise is reduced, and the life consumption of the lift motor 35 is suppressed. You can get the advantage.

Further, in this embodiment, when the access door 70 is opened while jam is occurring, it is highly possible that the feed roller separation determination unit 706 has opened the access door 70 for jam processing, and the supply is supplied. It is determined that the possibility that the feed roller 211 will be replaced is low. In this case, the feed roller separation determination unit 706 does not perform the separation operation according to the opening of the access door 70 (S103, S105). On the other hand, when the access door 70 is opened in a state where no jam has occurred, the feed roller separation determination unit 706 determines that the feed roller 211 is relatively likely to be replaced, and performs a separation operation. (S103, S104). That is, the separation operation can be performed more appropriately depending on the situation regarding the operating state of the image forming apparatus 1. When the access door 70 is opened in a state where a jam has occurred (S103: Yes), as in the second embodiment described later, in the case of a jam related to the feeding roller 211, a separation operation is performed (S103: Yes). S204 and S205) in FIG. 12 may be used.

(Modification example)
In this embodiment, the access door 70 for jam processing on the right side of the image forming apparatus 1 has been described as an example, but a dedicated door for replacing the feeding roller 211 may be installed. Further, although the description has been made based on the configuration in which one cassette is used, a configuration in which there are a plurality of cassettes may be used, or in a configuration in which each cassette is provided with an access door, a separation operation is performed when each access door is opened. It may be decided whether or not to do so according to each condition.

In this embodiment, as an example of the access door 70, a door member that is opened in a direction (E1) opposite to the pull-out direction E2 of the cassette 3 is illustrated, but in another direction (for example, the front side of FIG. 1, FIG. An opening / closing member that opens in the lower left direction of a) may be used. In that case, with the opening / closing member open, the feeding roller unit 21 is exposed so that it can be attached to and detached from the apparatus main body 1A. Further, the opening / closing member is not limited to the one that enables jam processing by opening the seat transport path, and may be a dedicated access door for replacing the feed roller unit 21.

Further, when a plurality of cassettes and a plurality of feeding roller units 21 are arranged in one device, an access door corresponding to each feeding roller unit 21 may be provided. In this case, for example, when any of the plurality of access doors is opened, it is determined whether or not the separation operation can be performed depending on whether or not the feed roller 211 corresponding to the access door has reached the replacement life. Just do it.

The embodiment of the second embodiment will be described with reference to FIGS. 10 to 12. Hereinafter, it is assumed that the elements having the same reference numerals as those in the first embodiment have substantially the same configuration and operation as those described in the first embodiment, and the parts different from the first embodiment will be described.

FIG. 10 shows the elevating mechanism 30 of the seat feeding unit according to the present embodiment. The elevating mechanism 30 of the present embodiment is not provided with a release lever 39 (FIGS. 5A and 5B) for separating the feed roller 211 from the seat in conjunction with the opening and closing of the cassette 3. Is different. That is, even if the cassette 3 is pulled out while the feeding roller 211 is in contact with the seat S loaded on the lift plate 31, the roller lifting lever 25 is not pushed up by the release lever 39. Therefore, after the cassette 3 is pulled out while the feeding roller 211 is in contact with the seat S, the feeding roller 211 does not separate above the seat unless the lift motor 35 is reversed.

Further, in the present embodiment, the feeding roller unit 21 can be visually observed from the outside of the image forming apparatus 1 not only by opening the access door 70 but also by pulling out the cassette 3. That is, with the cassette 3 removed from the apparatus main body 1A, the user can replace the feeding roller unit 21 through the opening for inserting the cassette 3 provided in the apparatus main body 1A.

FIG. 11 is a functional block diagram showing the control system of the image forming apparatus 1 in the second embodiment. The image forming apparatus control means 700 of this embodiment has the following functions in addition to the same functions (701 to 706) as those of the first embodiment.
The transport abnormality position determination unit 1001 (the transport abnormality position determination means of the present embodiment) determines whether or not the transport abnormality detected by the transport abnormality determination means is related to the feeding roller 211.
-When the operation unit 75 receives the separation instruction of the feeding roller 211, the separation request notification unit notifies the feeding roller separation determination unit 706 of the execution request (feeding roller separation request) of the separation operation of the feeding roller 211. 1002.

The transport abnormality position determination unit 1001 determines whether or not the jam is related to the feed roller 211 by the sensor that the transport abnormality determination unit 705 detects the jam. In this embodiment, when the registration sensor 76 detects the jam, it is determined that the jam is related to the feeding roller 211, and when the fixing / discharging sensor 77 and the discharging sensor 78 detect the jam, it is not related to the feeding roller 211. Judge as jam.

In the first embodiment, the operation of the feed roller separation determination unit 706 when the access door 70 is opened has been described. In this embodiment, the processing of the feed roller separation determination unit 706 when the cassette 3 is pulled out will be described. That is, in this embodiment, the cassette 3 is an example of an opening / closing member, and the cassette insertion / removal detecting unit 701 (FIG. 8) is an example of an opening / closing detecting means for detecting the opening / closing of the opening / closing member. Also in the configuration of this embodiment, the feeding roller 211 can be replaced by opening the access door 70 and attaching / detaching the feeding roller unit 21 as in the first embodiment.

FIG. 12 shows a flowchart of the process performed by the feed roller separation determination unit 706, which is started when the cassette insertion / removal detection unit 701 detects that the cassette 3 has been pulled out. The cassette insertion / removal sensor input circuit 610 (FIG. 7) provides information on whether the cassette 3 is inserted or removed based on the change in the detection signal of the cassette insertion / removal sensor 616, which is the open / close sensor of the present embodiment. Enter in.

In S201, the determination result of the roller life estimation unit 704 is confirmed, and if it is determined that the feeding roller 211 has reached the end of its life, the process proceeds to S202. It is judged that the possibility of replacing the feed roller 211 is low, and the process proceeds to S206.

In S202, it is confirmed from the determination result of the transport abnormality determination unit 705 whether or not a jam has occurred. Then, if no jam has occurred, the process proceeds to S203, the separation determination is determined to "separate operation", the process is terminated, and if a jam has occurred at any part of the transport path, the process proceeds to S204. ..

In S204, the location where the jam occurs is confirmed from the determination result of the transport abnormality determination unit 705. Then, if the determination result is "related to the feeding roller", it is assumed that the feeding roller 211 may be replaced at the same time as the jam processing, and the process proceeds to S205 to determine the separation determination to "separate operation". And end the process. If the determination result is "not related to the feeding roller", the process proceeds to S206, the separation determination is determined to "do not separate", and the process proceeds to S207.

In S207, the separation request notification unit 1002 confirms whether the feeding roller separation request from the operation unit 75 has been notified, and if notified, proceeds to S208, determines the separation determination to "separate operation", and processes. To finish. If not notified, the insertion / removal state of the cassette 3 detected by the cassette insertion / removal detection unit 701 is confirmed, and if it is inserted, the process of determining the separation of the feed roller is completed while the separation determination is set to "do not separate". do. If it has not been inserted, it moves to S207 and checks again whether the feed roller separation request has been notified.

In this embodiment, when the cassette 3 is pulled out, it is determined whether or not the separation operation can be executed depending on whether or not the feeding roller 211 has reached the replacement life as in the first embodiment (S201). That is, if the feed roller 211 has not reached the replacement life when the cassette 3 which is an example of the opening / closing member is opened, the feed roller separation determination unit 706 may replace the feed roller 211. Is determined to be low and the separation operation is not performed (S201, S206). On the other hand, when the cassette 3 is opened while the feed roller 211 has reached the replacement life, the feed roller separation determination unit 706 determines that there is a relatively high possibility that the feed roller 211 will be replaced. (S201, S203). In this way, by performing the separation operation more appropriately according to the situation regarding the state of the feed roller 211, the number of cases where the separation operation is performed unnecessarily is reduced, the operating noise is reduced, and the life consumption of the lift motor 35 is suppressed. You can get the advantage.

Further, in the present embodiment, when the cassette 3 is opened in the jam-generated state, in the case of the jam related to the feeding roller 211, the feeding roller separation determination unit 706 may replace the feeding roller 211. It is determined that there is a presence, and the separation operation is performed (S204, S205). On the other hand, when the cassette 3 is opened in the jam-generated state and the jam is not related to the feeding roller 211, the feeding roller separation determination unit 706 allows the user to use the cassette 3 for a purpose other than replacement of the feeding roller 211. Judge that it may have been opened. In this case, the feed roller separation determination unit 706 does not perform the separation operation (S204, S206). The purpose other than the replacement of the feeding roller 211 is, for example, the replenishment of the seat S. In this way, the separation operation can be performed more appropriately depending on the presence or absence of jam occurrence and the situation regarding the occurrence location.

In this embodiment, when the occurrence of jam is detected based on the detection result of the registration sensor 76, it is determined that the jam is related to the feeding roller 211, but it may be determined by another condition. For example, even if the jam is detected by the fixing / discharging sensor 77 or the discharging sensor 78, if it is estimated that the jam is generated before the rear end of the sheet S passes through the feeding roller 211, it is related to the feeding roller 211. You may judge.

(Other embodiments)
In the above-described first embodiment, the lifting mechanism 30 for raising and lowering the feeding roller unit 21 as the feeding means also serves as a mechanism for raising and lowering the lift plate 31 as the seat support portion, and is a common drive source for the lift motor. The configuration driven by 35 to move up and down has been described. The moving means for moving the feeding means is not limited to this, and a motor or a solenoid that drives only the raising and lowering of the feeding roller unit 21 may be used.

Further, the method of determining the life of the feeding roller 211 is not limited to the method of measuring the frequency of occurrence of the feeding delay described in the first embodiment. For example, when the cumulative number of times the image forming operation has been executed since the previous replacement of the feeding roller 211 (cumulative output number of images) exceeds a predetermined number, it is determined that the feeding roller 211 has reached the replacement life. You may do so. Further, for example, when the average value of the transport time T from the start of the feeding operation to the detection of the tip of the sheet S by the registration sensor 76 for the past predetermined number of feeding operations becomes longer than the predetermined threshold value. It may be determined that the feeding roller 211 has reached the replacement life.

Further, in the above Examples 1 and 2, the sheet feeding unit 2 which is a sheet feeding device incorporated in the image forming apparatus has been described. However, the present technology is not limited to this, and can be applied to a sheet feeding device installed separately from the image forming device. For example, there is a sheet feeding device which is connected to the image forming apparatus so as to form an image forming system together with the image forming apparatus and feeds a sheet as a recording material to the image forming apparatus.

The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

21 ... Feeding means (feeding roller unit) / 3 ... Opening / closing member (cassette) / 30, 35 ... Moving means (elevating mechanism, lift motor) / 31 ... Seat support (lift plate) / 70 ... Opening / closing member (access) Door) / 75 ... Display device, input device (operation unit) / 76, 77, 78 ... Sheet detection means (registration sensor, fixing discharge sensor, discharge sensor) / 600 ... Control means (image forming device control means) / 615 ... Opening and closing Sensor (door open / close sensor) / 701 ... Open / close detection means (cassette insertion / removal detection unit) / 702 ... Open / close detection means (door open / close detection unit) / 704 ... Life determination means (roller life estimation unit) / 705 ... Transport abnormality detection means ( Transport abnormality determination unit) / 706 ... Separation control means (feed roller separation determination unit) / 1001 ... Transport abnormality position determination means (transport abnormality position determination unit)

Claims (13)

The seat support part that supports the seat and
A feeding means for feeding the seat supported by the seat support portion, and
A moving means for moving the feeding means to a first position where the feeding means comes into contact with the sheet supported by the seat support portion and a second position where the feeding means is separated from the sheet supported by the seat supporting portion.
An opening / closing member that can be opened / closed and that can be attached / detached by opening the feeding means.
An opening / closing detecting means for detecting the opening / closing of the opening / closing member,
A life-determining means for determining whether or not the feeding means has reached the replacement life, and a life-determining means.
When the life determining means determines that the feeding means has reached the replacement life, the moving means moves the feeding means to the first position in response to the detection of the opening / closing member opening by the opening / closing detecting means. The separation operation of moving from the second position to the second position is executed.
When the life determining means determines that the feeding means has not reached the replacement life, the separation control means that does not execute the separation operation in response to the detection of the opening / closing of the opening / closing member by the opening / closing detecting means. Prepare
A sheet feeding device characterized by that. The seat support portion is attached to the main body of the seat feeding device so as to be retractable.
When the opening / closing member is opened while the seat support portion is attached, the feeding means can be attached and detached.
The sheet feeding device according to claim 1. When the seat support portion is pulled out while the feeding means is in the first position, the moving means moves the feeding means from the first position to the first position in conjunction with the movement of the seat supporting portion. It has an interlocking part that moves to two positions,
The separation control means is a case where the life determination means determines that the feeding means has reached the replacement life when the opening / closing member is opened while the seat support portion is pulled out from the device main body. However, the separation operation is not executed in response to the detection of the opening / closing of the opening / closing member by the opening / closing detecting means.
2. The sheet feeding device according to claim 2. The opening / closing member is configured so that when it is opened, at least a part of a transport path through which a sheet fed from the seat support portion is transported is opened.
The sheet feeding device according to any one of claims 1 to 3, wherein the sheet feeding device is characterized. A transport abnormality detecting means for detecting a transport abnormality of a sheet fed from the seat support portion is provided.
The separation control means
In a state where the transport abnormality detecting means has not detected a transport abnormality, when the life determining means determines that the feeding means has reached the replacement life, the opening / closing detecting means detects the opening of the opening / closing member. The separation operation is executed according to
In the state where the transport abnormality detecting means detects the transport abnormality, even when the life determining means determines that the feeding means has reached the replacement life, the opening / closing member by the opening / closing detecting means The separation operation is not executed in response to the detection of opening.
The sheet feeding device according to claim 4, wherein the sheet feeding device is characterized in that. A transport abnormality detecting means for detecting a transport abnormality of a sheet fed from the seat support portion, and a transport abnormality detecting means.
A transport abnormality position determining means for determining whether or not the transport abnormality detected by the transport abnormality detecting means is related to the feeding means is provided.
The separation control means
In a state where the transport abnormality detecting means has not detected a transport abnormality, when the life determining means determines that the feeding means has reached the replacement life, the opening / closing detecting means detects the opening of the opening / closing member. The separation operation is executed according to
When the transport abnormality detecting means detects a transport abnormality and the transport abnormality position determining means determines that the transport abnormality is related to the feed means, it is said that the life of the feed means has reached the replacement life. When the determination means determines, the separation operation is executed in response to the detection of the opening / closing member opening by the opening / closing detecting means, and the transport abnormality position determination is performed in a state where the transport abnormality detecting means detects the transport abnormality. When the means determines that the transport abnormality is not related to the feeding means, even when the life determining means determines that the feeding means has reached the replacement life, the opening / closing detecting means opens the opening / closing member. The separation operation is not executed in response to the detection of
The sheet feeding device according to claim 4, wherein the sheet feeding device is characterized in that. The seat support portion is a part of the opening / closing member, and is
The opening / closing member is attached to the main body of the seat feeding device so that it can be pulled out.
With the opening / closing member removed, the feeding means can be attached and detached.
The sheet feeding device according to claim 1. Equipped with a display device that displays information
When the seat support portion is pulled out while the feeding means is in the first position, the moving means moves the feeding means from the first position to the first position in conjunction with the movement of the seat supporting portion. It has an interlocking part that moves to two positions,
When the life determining means determines that the feeding means has reached the replacement life, the display device does not execute the separation operation in response to the detection of the opening / closing member opening by the opening / closing detecting means. In addition, it is configured to display information indicating that it is necessary to pull out the seat support portion when the feeding means is replaced.
The sheet feeding device according to claim 1 or 2. Equipped with an input device that accepts input operations to the sheet feeder
The separation control means did not execute the separation operation in response to the detection of the opening / closing member opening by the opening / closing detecting means when the life determining means determines that the feeding means has reached the replacement life. In this case, the separation operation is executed when a predetermined instruction is input via the input device before the opening / closing detecting means detects the closing of the opening / closing member.
The sheet feeding device according to any one of claims 1 to 8, wherein the sheet feeding device is characterized. The feeding means includes a feeding roller arranged above the seat support portion and a holder that rotatably holds the feeding roller, and the swing of the holder causes the feeding roller to move. It moves to the first position where the feeding roller abuts on the upper surface of the sheet supported by the seat support portion and the second position where the feeding roller is separated from the upper surface of the sheet supported by the seat support portion.
The sheet feeding device according to any one of claims 1 to 9, wherein the sheet feeding device is characterized. A seat sensor that changes the detection signal depending on the presence or absence of a seat at the detection position downstream of the feeding means in the seat transport direction is provided.
In the life determining means, the frequency of occurrence of the feeding operation exceeding a preset threshold value from the start of the feeding operation until the tip of the sheet in the sheet transporting direction reaches the detection position is a predetermined frequency. In the above case, it is determined that the feeding means has reached the replacement life, and when the frequency of occurrence of the feeding operation in which the transport time exceeds the threshold value is lower than the predetermined frequency, the feeding means reaches the replacement life. Judge that it has not arrived,
The sheet feeding device according to any one of claims 1 to 10. The seat support part that supports the seat and
A feeding means for feeding the seat supported by the seat support portion, and
A moving means for moving the feeding means to a first position where the feeding means comes into contact with the sheet supported by the seat support portion and a second position where the feeding means is separated from the sheet supported by the seat supporting portion.
An opening / closing member that can be opened / closed and that can be attached / detached by opening the feeding means.
An open / close sensor whose detection signal changes according to the open / close of the open / close member,
A seat sensor whose detection signal changes depending on the presence or absence of a seat at a detection position downstream of the feeding means in the seat transport direction.
A control means for executing a separation operation for moving the feeding means from the first position to the second position by the moving means is provided.
The control means
When the frequency of occurrence of the feeding operation exceeding the preset threshold value from the start of the feeding operation to the arrival of the tip of the sheet in the sheet transporting direction at the detection position is equal to or higher than the predetermined frequency, the above-mentioned The separation operation is executed in response to a change in the detection signal of the open / close sensor due to the opening of the open / close member.
When the frequency of occurrence of the feeding operation exceeding the threshold value is lower than the predetermined frequency, the separation operation is not executed in response to a change in the detection signal of the opening / closing sensor due to the opening of the opening / closing member.
A sheet feeding device characterized by that. The sheet feeding device according to any one of claims 1 to 12,
An image forming means for forming an image on a sheet fed from the sheet feeding device is provided.
An image forming apparatus characterized in that.

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