JP6344183B2 - Paper feeding device and printing device - Google Patents

Description

  The present invention relates to a paper feeding device and a printing device. More specifically, the present invention relates to a technique for suppressing unexpected rotation of a paper feed roller.

  2. Description of the Related Art Conventionally, a technique for controlling the rotation of a sheet feeding roller using a solenoid in a sheet feeding apparatus that supplies sheets is known. The solenoid is connected to a lock portion that locks the rotation of the paper feed gear that rotates the paper feed roller. When the solenoid is not energized, the sheet feeding device is in a state where the rotation of the sheet feeding gear is restricted by the lock unit. When the solenoid is energized, the solenoid removes the lock unit from the sheet feeding gear, and the sheet feeding gear Is configured to rotate.

  For example, Patent Document 1 discloses a document that discloses a sheet feeding device having the above-described configuration. Patent Document 1 discloses a sheet feeding device that feeds sheets from a multi-sheet feeding tray, and restricts the lock unit from being detached from the sheet feeding gear when the tray is closed. In Cited Document 1, by restricting the lock part, it is assumed that the lock part is prevented from being inadvertently released due to vibrations or the like during transportation.

Japanese Patent Laid-Open No. 11-11709

  However, the conventional technique described above has the following problems. That is, when the tray is open, the restricting portion does not restrict the lock portion, so that the lock portion may be inadvertently released due to vibration or the like during sheet conveyance. For example, in a multi-function peripheral equipped with a reading device at the top of the printing device, when the user opens and closes the document cover during continuous feeding in the printing device, the lock portion is unlocked due to vibrations associated with the opening and closing operation. There is a possibility that paper will be fed at an unintended timing.

  The present invention has been made to solve the above-described problems of the prior art. That is, the subject is to provide a technique for reducing paper feeding at an unintended timing by inadvertently unlocking the lock portion that locks the rotation of the paper feeding gear during continuous paper feeding. There is.

  In order to solve this problem, a paper feeding device includes a housing portion that accommodates a sheet, a paper feeding roller that carries a sheet accommodated in the housing portion, and a paper feeding roller that is carried by the paper feeding roller to convey the inside of the device. A sheet abutting portion that is in contact with the sheet to be moved and is in contact with the sheet, and a sheet abutting position that is not in contact with the sheet, and a sheet feeding portion that rotates the sheet feeding roller. A lock portion that is in contact with the gear and the paper feed gear, and that is displaced between a lock position that locks the rotation of the paper feed gear, and a non-lock position that does not lock the rotation of the paper feed gear, and the lock The locking portion is placed in a different position between the unlocking position and the locking position when energized and not energized, and the locking portion is moved to the unlocked position. The lock part The solenoid that unlocks the paper feeding gear and the sheet contact portion interlocked with the sheet contact portion, and when the sheet contact portion is in the sheet contact position, the unlocking portion of the lock portion in the lock position is In a state in which the sheet contact portion is in the first position that restricts movement to the position and the sheet contact portion is in the non-sheet contact position, a restriction portion in a second position that is not restricted is provided.

  A sheet feeding device disclosed in this specification includes a sheet abutting portion that abuts on a sheet carried by a sheet feeding roller, a sheet feeding gear that rotates the sheet feeding roller, and a lock that locks the rotation of the sheet feeding gear. Part, a solenoid for releasing the lock of the lock part, and a restricting part for restricting the movement of the lock part. When the sheet contact portion is in contact with the sheet and is in the sheet contact position, the restricting portion is in the first position, and the lock portion is moved to the unlocked position where the rotation of the paper feed gear is not locked. regulate. In a state where the sheet contact portion does not contact the sheet and is in the sheet non-contact position, the restriction portion is in the second position, and movement of the lock portion to the non-lock position is not restricted.

  In other words, in the sheet feeding device disclosed in this specification, while the sheet conveyed through the device is in contact with the sheet contact portion, the restriction portion moves from the lock position of the lock portion to the non-lock position. Because of the restriction, even if vibration or the like occurs during sheet conveyance, the lock portion is difficult to unlock. As a result, it is possible to reduce paper feeding at unintended timing during continuous paper feeding.

  The sheet feeder disclosed in the present specification includes a fixing unit that is fixed to the apparatus main body and that restricts movement of the restricting unit at the first position to the side opposite to the second position. Good. While the sheet is in contact with the sheet contact portion, the fixed portion fixed to the apparatus body restricts the movement of the restriction portion in the first position to the opposite side of the second position. , The movement of the lock part can be reliably controlled.

  Moreover, the said fixing | fixed part is good to contact | abut the said control part in the state which has the said control part in the said 1st position. Since the movement of the restricting portion is directly restricted by contacting the restricting portion, the load on other members such as the sheet contacting portion is small.

  The sheet feeding device disclosed in this specification may include a sensor that outputs different signals depending on whether the sheet contact portion is in the sheet contact position or the sheet non-contact position. . Since the sheet contact portion is also used as a sensor that outputs different signals depending on the presence or absence of a sheet, an increase in the number of parts can be suppressed.

  The sheet feeding device disclosed in the present specification includes a drawing roller that pulls in a sheet carried by the sheet feeding roller at a predetermined timing, and the sheet contact portion conveys the sheet more than the drawing roller. It may be in contact with the sheet on the downstream side in the direction. On the upstream side of the pull-in roller, a plurality of sheets that could not be separated may be transported, and the contact state with the sheets may continue for a long period of time, and the restriction unit may interfere with the original paper feeding. is there. Therefore, it is preferable that the sheet contact portion is on the downstream side of the drawing roller.

  The sheet feeding device disclosed in the present specification further includes a process unit that prints an image on a sheet pulled by the pulling roller or reads an image of the sheet, and the sheet contact unit includes the process unit. It is better to contact the sheet on the upstream side in the sheet conveyance direction. Even at the downstream side of the pull-in roller, the longer the conveyance distance from the paper feed roller, the longer the period during which the restricting portion does not restrict the movement of the lock portion, and the productivity decreases. Therefore, it is preferable that the sheet contact portion is at least upstream of the process portion.

  Further, the present specification includes a storage unit that stores a sheet, a paper feed roller that carries a sheet stored in the storage unit, and a printing unit that prints an image on the sheet carried by the paper feed roller. , The sheet contact position that is in contact with the sheet that is carried in by the sheet feed roller and is conveyed through the apparatus toward the printing unit, and the sheet non-contact position that is not in contact A sheet abutting portion that displaces the sheet feeding roller, a sheet feeding gear that rotates the sheet feeding roller, a lock position that locks the rotation of the sheet feeding gear, and the sheet feeding gear. A lock portion that is displaced at a non-lock position that does not lock the rotation of the gear, and is connected to the lock portion, and the lock portion is either one of the non-lock position and the lock position when energized or not energized In a different position A solenoid that moves the lock portion to the unlocked position and unlocks the paper feed gear by the lock portion, and the sheet contact portion is interlocked with the sheet contact portion, and the sheet contact portion is in the sheet contact position. Is in the first position for restricting movement of the lock portion in the lock position to the non-lock position, and is not restricted in a state in which the sheet contact portion is in the sheet non-contact position. A printing device is disclosed that includes a restriction portion in a second position.

  The printing apparatus disclosed in the present specification is provided with a document table, a reading unit that reads an image of a document on the document table, and is openable and closable with respect to the document table. It is preferable to provide a cover portion for pressing the document on the top. When the cover part is opened and closed, the device is likely to vibrate. Therefore, the configuration of the present application works favorably.

  According to the present invention, it is possible to realize a technique for reducing paper feeding at an unintended timing by inadvertently unlocking a lock unit that locks rotation of a paper feeding gear during continuous paper feeding.

1 is a perspective view showing a schematic appearance of an MFP according to an embodiment. 2 is a cross-sectional view illustrating a schematic configuration of an image forming unit of the MFP. FIG. It is explanatory drawing which shows a sheet sensor. It is explanatory drawing which shows the gear structure in a non-paper feeding state. It is explanatory drawing which shows the gear structure in a rotation state. It is explanatory drawing which shows the position of a control member. It is explanatory drawing which shows the control position of a control member. It is explanatory drawing which shows the positional relationship of a sheet sensor and a control member. It is explanatory drawing which shows the positional relationship of the rotation piece of a sheet sensor, and a control member. It is explanatory drawing which shows the positional relationship of the rotation piece of a sheet sensor, and a control member. It is explanatory drawing which shows another example of the attachment method of a solenoid. It is explanatory drawing which shows another example of a stopper.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an image forming apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. In the present embodiment, the present invention is applied to a multi function peripheral (MFP) having a paper feed function.

  As shown in FIG. 1, the MFP 100 according to the present embodiment includes an image forming unit 10 that prints an image on a sheet, a document reading unit 20 that reads an image of a document, and an operation that displays an operation status and receives an input operation by a user. Panel 40. The operation panel 40 includes a button group 41 including a start key, a stop key, a numeric keypad, and the like, and a liquid crystal display 42, and receives an instruction input by a user. The MFP 100 further includes a paper feed cassette 51 that stores printing sheets and a paper discharge port 52 that discharges printed sheets. The paper feed cassette 51 is an example of a storage unit.

  As shown in FIG. 1, the document reading unit 20 includes an image sensor 22 for optically reading an image, a contact glass 23, and an ADF (automatic document feeder) 24. The image sensor 22 has a plurality of optical elements. The document reading unit 20 irradiates the document with light while relatively moving the image sensor 22 and the document, and reads an image of the document based on the amount of light received by each optical element. The image sensor 22 is an example of a reading unit. The document reading unit 20 of the MFP 100 may be capable of color reading or only monochrome reading.

  The ADF 24 is provided so as to be openable and closable with respect to the upper surface of the contact glass 23 as indicated by an arrow in FIG. For example, the MFP 100 can cause the document reading unit 20 to read an image of the document by moving the image sensor 22 along the document fixed on the contact glass 23. In this case, the user sets the document on the contact glass 23 with the ADF 24 opened, and presses the document with the ADF 24 with the ADF 24 closed. After reading the original, the user opens the ADF 24 again and removes the original. The contact glass 23 is an example of a document table, and the ADF 24 is an example of a cover unit. Note that the MFP 100 can cause the document reading unit 20 to read the image of the document by transporting the document to the position facing the image sensor 22 fixed at a predetermined position by the ADF 24 in the closed state.

  As shown in FIG. 2, the image forming unit 10 includes a process unit 11 that forms a toner image on a sheet by an electrophotographic method, and a fixing unit 12 that fixes the formed toner image on the sheet. Further, the MFP 100 sequentially conveys the sheets stored in the sheet feeding cassette 51 toward the sheet discharge port 52 via the process unit 11 and the fixing unit 12 in order from the upstream side in the sheet conveyance direction. A pickup roller 13, a separation roller 14, a registration roller 15, and a paper discharge roller 16 are provided. The registration roller 15 is a pair of rollers, and the paper discharge roller 16 is a triple roller. The pickup roller 13 is an example of a paper feed roller, and the registration roller 15 is an example of a drawing roller.

  In the image forming unit 10 of the MFP 100, a sheet conveyance path 17 is formed as indicated by a dashed line arrow in FIG. That is, when printing is performed, the MFP 100 pulls out the sheet stored in the paper feed cassette 51 from the paper feed cassette 51 by the pickup roller 13 and sends out only one of them by the separation roller 14. Further, in synchronization with the operation of the process unit 11, the MFP 100 pulls the sheet into the process unit 11 by the registration roller 15 and causes the process unit 11 to form a toner image on the sheet. Next, the MFP 100 causes the fixing unit 12 to fix the toner image on the sheet, and discharges the fixed sheet to the paper discharge port 52 by the paper discharge roller 16. The process unit 11 is an example of a process unit and an example of a printing unit.

  Further, as shown in FIG. 2, the MFP 100 includes sheet sensors 61, 62, and 63 that output signals according to the presence / absence of sheets at a plurality of locations in the sheet conveyance path 17. The sheet sensor 61 is disposed downstream of the separation roller 14 and upstream of the registration roller 15 in the sheet conveyance direction. The sheet sensor 62 is disposed downstream of the registration rollers 15 and upstream of the process unit 11 in the sheet conveyance direction. The sheet sensor 63 is disposed downstream of the fixing unit 12 and upstream of the paper discharge roller 16 in the sheet conveyance direction.

  As shown in FIG. 3, the sheet sensor 62 is a transmissive photosensor having a light emitting unit 621 and a light receiving unit 622 facing each other with a predetermined interval. The sheet sensor 62 is a so-called groove type sensor in which a light emitting unit 621 and a light receiving unit 622 are integrally formed, and a groove 623 is provided between the light emitting unit 621 and the light receiving unit 622. The sheet sensor 62 is an example of a sensor. Further, the sheet sensors 61 and 63 have the same configuration as the sheet sensor 62.

  As shown in FIG. 3, a rotating piece 65 attached so as to be rotatable along the direction of the groove of the groove 623 is disposed at a position facing the groove 623 of the sheet sensor 62. The rotating piece 65 includes a blocking unit 651 that blocks light from the light emitting unit 621 in a state where the rotating piece 65 is located in a space formed by the groove unit 623, and a contact unit 652 that protrudes on the conveyance path 17 and can contact the sheet S. And is attached to a rotatable rotating shaft 66. The rotation shaft 66 is fixed at a position between the blocking portion 651 and the contact portion 652 and is disposed in parallel to the direction connecting the light emitting portion 621 and the light receiving portion 622.

  The sheet S conveyed on the conveyance path 17 is conveyed from the bottom to the top in FIG. 3 as indicated by the one-dot chain line arrow. When the leading end of the sheet S comes into contact with the contact portion 652 of the rotary piece 65, the contact portion 652 is pushed up by the sheet S, and the rotary piece 65 rotates. As a result, the rotating piece 65 is displaced from a non-contact position 65A indicated by a solid line in FIG. 3 to a contact position 65B indicated by a two-dot chain line in FIG. When the sheet S is continuously conveyed and does not come into contact with the contact portion 652, the contact portion 65 is not contacted by a restoring force such as a spring or its own weight as shown by a solid line in FIG. Return to position 65A.

  That is, the rotating piece 65 is displaced by the sheet S, and is positioned at the contact position 65B during the period in which the sheet S is in the range in which the rotary piece 65 is in contact with the contact portion 652, and the sheet S is in the range in contact with the contact portion 652. During the absence period, it is located at the non-contact position 65A. The rotating piece 65 is an example of a sheet contact portion, the contact position 65B is an example of a sheet contact position, and the non-contact position 65A is an example of a sheet non-contact position.

  In the rotating piece 65, since the contact portion 652 and the blocking portion 651 are integrally formed, the blocking portion 651 is also displaced by the displacement of the contact portion 652. That is, at the contact position 65B where the contact portion 652 is in contact with the sheet S, the blocking portion 651 is disposed at a position other than between the light emitting portion 621 and the light receiving portion 622 and does not block the light of the sheet sensor 62. . On the other hand, in the non-contact position 65A where the contact portion 652 is not in contact with the sheet S, the blocking portion 651 is disposed between the light emitting portion 621 and the light receiving portion 622 and blocks the light of the sheet sensor 62. Thereby, the sheet sensor 62 outputs different signals depending on whether the rotary piece 65 is in the contact position 65B or in the non-contact position 65A.

  Next, the pickup roller 13 shown in FIG. 2 will be described in detail. In the MFP 100, various rotating members such as a plurality of conveying rollers and a photosensitive member in the process unit 11 including the pickup roller 13 are driven by one main motor (not shown). For example, during execution of a print job, the MFP 100 continuously rotates the main motor. On the other hand, the MFP 100 rotates the pick-up roller 13 only when the sheet is pulled out from the paper feed cassette 51, and stops when the sheet is not pulled out.

  Therefore, as shown in FIG. 4, the pickup roller 13 includes a missing gear 71 and a cam 72 as a configuration for restricting transmission of the driving force of the main motor. The toothless gear 71 is provided adjacent to the transmission gear 73 that always rotates when the main motor rotates. The toothless gear 71 is formed with a gear portion 711 that meshes with the transmission gear 73 and a toothless portion 712 that does not mesh with the transmission gear 73. The cam 72 is a substantially disk-shaped member having a stepped portion 721 at one place and a portion other than the stepped portion 721 having a smooth curved shape. The cam 72 is attached with a pulling spring 75 that urges rotation in one direction.

  The toothless gear 71 and the cam 72 rotate integrally around the rotation shaft 74. The rotation shaft 74 is also linked to the pickup roller 13, so that the pickup roller 13 rotates when the rotation shaft 74 rotates, and the pickup roller 13 does not rotate unless the rotation shaft 74 rotates. The rotating shaft 74 may be the rotating shaft of the pickup roller 13 or may be configured to be rotated via another gear or the like. That is, the gear in which the toothless gear 71 and the cam 72 are integrally attached is an example of a paper feed gear that rotates the pickup roller 13.

  Further, as shown in FIG. 4, the MFP 100 includes a lock bar 76, a solenoid 77, a regulating member 78, and a stopper 79. The lock bar 76 is a rod-shaped member having a key portion 761 that is bent at one end, and is rotatably attached to a rotating shaft 763 provided near the center in the longitudinal direction. Further, the solenoid 77 has an actuator 771 and a return spring 772. In the lock bar 76, the key portion 761 on one end side can be engaged with the stepped portion 721 of the cam 72, and the end portion 762 on the other end side is fixed to the tip portion of the actuator 771 of the solenoid 77. . The lock bar 76 is an example of a lock unit.

  When the solenoid 77 is not energized, the actuator 771 is pulled out by the return spring 772. The solenoid 77 pulls the actuator 771 against the urging force of the return spring 772 when energized. As a result, the end 762 of the lock bar 76 moves together with the actuator 771, so that the lock bar 76 rotates around the rotation shaft 763. That is, the solenoid 77 displaces the lock bar 76 at different positions when energized and when not energized.

  Specifically, in the MFP 100 of this embodiment, when the solenoid 77 is not energized, as shown in FIG. 4, the end 762 is lifted together with the actuator 771, the key 761 is lowered, and the key 761 and the step 721 are separated. opposite. Thereby, the lock bar 76 locks the rotation of the cam 72 at least in the clockwise direction in FIG. That is, when the solenoid 77 is not energized, the key portion 761 is positioned at a locking position 761A where the stepped portion 721 of the cam 72 is locked. The position of the lock bar 76 in a state where the key portion 761 is at the locking position 761A is an example of a lock position where the rotation of the cam 72 is locked.

  On the other hand, when the solenoid 77 is energized, the end 762 is pulled down together with the actuator 771, so that the lock bar 76 rotates counterclockwise in FIG. 4 and the key 761 is pulled up. As shown in FIG. 5, the key portion 761 is in a position that does not face the stepped portion 721. In this position, the lock bar 76 does not lock the rotation of the cam 72. That is, the solenoid 77 unlocks the rotation of the cam 72 by the lock bar 76 when energized. When the solenoid 77 is energized, the key portion 761 is located at the non-locking position 761B where the stepped portion 721 of the cam 72 is not locked. The position of the lock bar 76 in a state where the key portion 76 is in the non-locking position 761B is an example of a non-locking position where the rotation of the cam 72 is not locked.

  As shown in FIG. 4, the restricting member 78 is disposed above the key portion 761 of the lock bar 76, and includes a restricting position 78 </ b> A indicated by a solid line in FIG. 4 and an unrestricted position 78 </ b> B indicated by a two-dot chain line in FIG. 4. It is a rod-shaped member which can rotate between. The regulating member 78 is rotatably attached to the rotary shaft 66 of the rotary piece 65 of the sheet sensor 62 described above, and rotates in conjunction with the rotation of the rotary piece 65. The rotating shaft 66 of the restricting member 78 and the rotating shaft 763 of the lock bar 76 are arranged substantially in parallel, and both the restricting member 78 and the lock bar 76 rotate within the same plane shown in FIG. Moving.

  The rotating shaft 66 of the regulating member 78 is above the key portion 761 of the lock bar 76 in FIG. Further, the restricting member 78 is disposed above such that the restricting member 78 does not come into contact with the missing gear 71 and the cam 72, and the rotation angle range of the restricting member 78 is 90 degrees or less. The restricting member 78 has a portion below the rotating shaft 66 disposed on the end 762 side of the lock bar 76 at the restricting position 78A, and a portion below the rotating shaft 66 is the key portion of the lock bar 76 at the non-regulating position 78B. 761 side. That is, in FIG. 4, the inclination of the restricting member 78 is lower left at the restriction position 78A and lower right at the non-restriction position 78B.

  The stopper 79 is fixed to the apparatus main body of the MFP 100. The stopper 79 abuts on the restriction member 78 located at the restriction position 78A and restricts the movement range of the restriction member 78. That is, the stopper 79 restricts the restriction member 78 at the restriction position 78A from moving to the side opposite to the non-restriction position 78B. The restriction member 78 is an example of a restriction part, and the stopper 79 is an example of a fixed part. Further, the restriction position 78A is an example of a first position, and the non-restriction position 78B is an example of a second position. Details of the regulating member 78 and the stopper 79 will be described later.

  Next, a paper feeding operation in MFP 100 will be described. FIG. 4 shows a non-paper feeding state in which the MFP 100 is not feeding paper by the pickup roller 13. Since the toothless portion 712 of the missing gear 71 is disposed at a position facing the transmission gear 73, the rotation of the transmission gear 73 is not transmitted to the missing gear 71. That is, in the non-feeding state, the missing gear 71 does not receive the rotational driving force regardless of the rotation state of the transmission gear 73.

  In the non-feeding state shown in FIG. 4, the solenoid 77 is not energized, and the actuator 771 is pulled up by the return spring 772. The key portion 761 is located at a locking position 761A where the stepped portion 721 of the cam 72 is locked. That is, the rotation of the cam 72 in the clockwise direction in FIG. 4 is restricted by the key portion 761 of the lock bar 76. The cam 72 is urged to rotate clockwise in FIG. 4 by the urging force of the tension spring 75. Thereby, the cam 72 does not rotate in any direction in the non-feeding state. Accordingly, the pickup roller 13 does not rotate in the non-feeding state.

  On the other hand, when feeding a sheet, the MFP 100 energizes the solenoid 77 to enter the feeding state shown in FIG. In the paper feeding state, the main motor is rotated and the transmission gear 73 is rotating. As shown in FIG. 5, the solenoid 77 pulls down the actuator 771 against the urging force of the return spring 772 by energization. Since the end 762 of the lock bar 76 is also lowered, the lock bar 76 rotates counterclockwise in FIG. 5 about the rotation shaft 763. As a result, the key portion 761 of the lock bar 76 is located at the non-locking position 761B where the stepped portion 721 of the cam 72 is not locked.

  The cam 72 is rotated in the clockwise direction in FIG. 5 by the urging force of the pulling spring 75 as indicated by the arrow in FIG. Further, the toothless gear 71 integrated with the cam 72 rotates, and the gear portion 711 of the toothless gear 71 meshes with the transmission gear 73. Thereby, the rotation of the transmission gear 73 is transmitted to the missing gear 71, the missing gear 71 is rotated by the driving force of the main motor, and the pickup roller 13 is rotated by the rotation of the missing gear 71. The cam 72 is rotated integrally with the toothless gear 71 against the urging force of the tension spring 75.

  The MFP 100 stops energization of the solenoid 77 when a predetermined time elapses after the pickup roller 13 starts rotating. The predetermined time is shorter than the time required for one rotation of the cam 72. The actuator 771 is pulled up by the urging force of the return spring 772, and the lock bar 76 rotates clockwise in FIG. However, since the cam 72 has started to rotate, the stepped portion 721 of the cam 72 is not directly below the key portion 761. Therefore, the tip of the key portion 761 of the lock bar 76 comes into contact with the outer periphery of the cam 72. Since the pressing force applied to the cam 72 by the lock bar 76 does not hinder the rotation of the cam 72, the cam 72 rotates with the tip of the key portion 761 and the cam 72 in contact with each other.

  When the missing tooth gear 71 rotates almost once, the missing tooth portion 712 and the transmission gear 73 face each other. Thereby, the toothless gear 71 does not receive the transmission of the driving force of the transmission gear 73. Further, the stepped portion 721 of the cam 72 reaches a contact position with the key portion 761, and the key portion 761 is locked to the stepped portion 721 of the cam 72. For this reason, the rotation of the cam 72 is stopped and a non-paper feeding state is entered. That is, after feeding one sheet, the MFP 100 stops the pickup roller 13 and enters the non-feed state again.

  As described above, the pressing force of the lock bar 76 toward the cam 72 is not large. Further, when the solenoid 77 is energized, the lock bar 76 and the cam 72 are required to be easily unlocked, so the key portion 761 and the stepped portion 721 cannot be made too large. For this reason, there is a problem that the locking portion between the lock bar 76 and the cam 72 in the non-feeding state is easily detached due to vibration. For example, if the user opens / closes the ADF 24 vigorously during continuous feeding or the user collides with the apparatus main body, the lock between the lock bar 76 and the cam 72 may be released due to the vibration. Since the transmission gear 73 is rotating during continuous feeding, the pickup roller 13 is rotated and the sheet is fed even when the lock is released even at an unscheduled timing. Since the MFP 100 according to the present embodiment includes the restriction member 78, such an unscheduled sheet feeding operation is suppressed.

  Next, a mechanism for suppressing the above-mentioned unplanned sheet feeding operation by the regulating member 78 will be described in detail. The restriction member 78 of the MFP 100 prevents the locking portion between the lock bar 76 and the cam 72 from coming off at an unscheduled timing due to vibration or the like. 6 and 7 show the vicinity of the regulating member 78 in an enlarged manner.

  As described above, the MFP 100 according to the present embodiment includes the restriction member 78 disposed above the key portion 761 of the lock bar 76. The lock bar 76 rotates due to a change between energization and non-energization of the solenoid 77, and the key portion 761 has a locking position 761 </ b> A for locking the stepped portion 721 of the cam 72 and a non-locking position 761 </ b> B that is not locked. Displace between. The restricting member 78 restricts the movement of the key portion 761 from the locking position 761A to the non-locking position 761B at the restriction position 78A indicated by a solid line in FIG. The movement is not restricted at the restriction position 78B.

  Specifically, at the restriction position 78A, at least a part of the restriction member 78 is disposed at a position that intersects the movement path of the lock bar 76 from the locking position 761A of the key portion 761 to the non-locking position 761B. Therefore, in a state in which the restricting member 78 is at the restricting position 78A, for example, as shown by a two-dot chain line in FIG. 7, the key portion 761 of the lock bar 76 is changed from the locking position 761A to the non-locking position 761B. In contact with the regulating member 78 in the middle of the displacement. Since the lock bar 76 is displaced counterclockwise as described above, the direction of contact of the lock bar 76 with the regulating member 78 is the direction from the lower right to the upper left in FIG.

  The contact portion of the lock bar 76 against the restriction member 78 is a tip portion below the rotation shaft 66 of the restriction member 78. The contact direction is the clockwise direction of the regulating member 78 and is the opposite direction to the non-regulating position 78B when viewed from the regulating member 78 at the regulating position 78A. The restricting member 78 at the restricting position 78A is restricted from rotating in the clockwise direction in FIG. 7 by a stopper 79 fixed to the apparatus main body. The stopper 79 restricts the movement of the restricting member 78 beyond the restricting position 78 </ b> A in the direction from the non-regulating position 78 </ b> B toward the restricting position 78 </ b> A. Therefore, the regulating member 78 does not further rotate clockwise from the regulating position 78A due to the contact of the lock bar 76.

  In the MFP 100, for example, when vibration is received without energizing the solenoid 77, the lock bar 76 springs against the urging force of the return spring 772, and the key portion 761 moves from the locking position 761A to the non-locking position 761B. There is a possibility of starting to move toward. Even in this case, the key portion 761 does not reach the non-locking position 761B by contacting the restriction member 78 at the restriction position 78A, so that the lock between the key portion 761 and the stepped portion 721 cannot be released. Therefore, the cam 72 and the pickup roller 13 do not rotate and the sheet is not fed.

  On the other hand, in the state where the regulating member 78 is in the non-regulating position 78B, the movement of the lock portion 761 of the lock bar 76 from the locking position 761A to the non-locking position 761B is hindered as shown by a two-dot chain line in FIG. I can't. The portion of the restricting member 78 below the rotation shaft 66 is on the right side of the key portion 761, and the stopper 79 is located above the key portion 761 of the non-locking position 761B. Accordingly, when the solenoid 77 is energized, the lock bar 76 rotates counterclockwise in the drawing and the lock portion 761 and the stepped portion 721 are unlocked, so that the pickup roller 13 rotates once at the originally scheduled timing. , One sheet is fed.

  Further, as shown in FIG. 8, the regulating member 78 of the MFP 100 is rotatably attached to the rotary shaft 66 of the rotary piece 65 of the sheet sensor 62 described above, and rotates in conjunction with the rotation of the rotary piece 65. That is, both the regulating member 78 and the rotating piece 65 are fixed to the rotating shaft 66. As shown in FIG. 3, when the sheet S comes into contact with the rotating piece 65 and the rotating piece 65 rotates, the regulating member 78 also rotates. For example, as shown in FIG. 8, the sheet sensor 62 and the rotating piece 65 are provided at the center of the sheet passing range, and the regulating member 78 is provided outside the sheet passing range. Yes.

  Next, FIGS. 9 and 10 are views of the rotary shaft 66 viewed in the axial direction. In a state where the sheet S is not in contact with the rotating piece 65 and the rotating piece 65 is in the non-contact position 65A, the restricting member 78 is positioned in the non-restricting position 78B as shown in FIG. In this state, since the blocking unit 651 of the rotating piece 65 blocks light, the sheet sensor 62 outputs a signal corresponding to the absence of a sheet.

  On the other hand, when the sheet S being conveyed contacts the rotating piece 65 and the rotating piece 65 is in the contact position 65B, the restricting member 78 is positioned at the restricting position 78A as shown in FIG. That is, in MFP 100, while sheet S is being conveyed at the detection position of sheet sensor 62, locking between stepped portion 721 of cam 72 and key portion 761 of lock bar 76 is not released by regulating member 78. As a result, the rotation of the pickup roller 13 is restricted, so that the MFP 100 does not start conveying the next sheet. In this state, as shown in FIG. 10, the blocking unit 651 of the rotating piece 65 does not block the light, so the sheet sensor 62 outputs a signal corresponding to the presence of the sheet.

  Next, an operation when the MFP 100 executes continuous printing will be described. When the MFP 100 receives a print job, the MFP 100 starts conveying the sheet and prints on the sheet. When the received print job is printing a plurality of sheets and printing is performed continuously, the MFP 100 controls the sheet conveyance and printing timing based on the output signal of the sheet sensor 62.

  Specifically, the MFP 100 first starts the rotation of the main motor and executes initial operations of the process unit 11 and the fixing unit 12. At this time, the solenoid 77 is not energized, the key portion 761 of the lock bar 76 and the stepped portion 721 of the cam 72 are locked, and the pickup roller 13 does not rotate. Further, since the sheet passing is not started, the rotating piece 65 of the sheet sensor 62 is located at the non-contact position 65A, and the regulating member 78 is located at the non-regulating position 78B.

  When the initial operation of the process unit 11 or the like is completed, the MFP 100 starts feeding the first sheet. Specifically, the MFP 100 energizes the solenoid 77 to release the lock between the key portion 761 of the lock bar 76 and the step portion 721 of the cam 72. In the state where the sheet is not conveyed, the regulating member 78 is located at the non-regulating position 78B, so that the lock is appropriately released. As a result, the pickup roller 13 rotates and the first sheet is fed.

  When the first sheet reaches the position of the sheet sensor 62, the rotating piece 65 of the sheet sensor 62 is rotated by the sheet to reach the contact position 65B, and the restriction member 78 becomes the restriction position 78A. In this state, even if the key portion 761 of the lock bar 76 starts to be displaced away from the stepped portion 721 of the cam 72, the lock between the key portion 761 and the stepped portion 721 is locked by the restriction member 78. It will not be released. That is, while the sheet is at the position of the sheet sensor 62, feeding of the next sheet is not started. Note that the first sheet is further conveyed and printed by reaching the process unit 11.

  When the first sheet finishes passing through the position of the sheet sensor 62, the rotating piece 65 of the sheet sensor 62 returns to the non-contact position 65A, and the restriction member 78 becomes the non-restriction position 78B. Further, as the rotating piece 65 rotates, the signal output from the sheet sensor 62 changes to a signal corresponding to no sheet. After receiving a signal corresponding to no sheet from the sheet sensor 62, the MFP 100 controls the sheet feeding timing by energizing the solenoid 77 in accordance with the printing timing of the next sheet, similarly to the first sheet.

  The MFP 100 prints an image on a sheet in accordance with the timing of the operation of the process unit 11 and the fixing unit 12 and the sheet conveyance position based on the output signal of the sheet sensor 62. That is, the sheet conveyance timing is controlled in accordance with the operation of the process unit 11 and the like by the energization timing of the solenoid 77. For example, it is not preferable to start feeding at an unintended timing due to vibration or the like because the position of the sheet and the control of the process unit 11 and the like do not match. In MFP 100 of this embodiment, while receiving a signal corresponding to the presence of a sheet from sheet sensor 62, displacement of lock bar 76 is regulated by regulating member 78, and the lock by lock bar 76 is not released, so the next sheet Is not started. In other words, at least the preceding sheet does not pass through the position of the sheet sensor 62, so that the next sheet is prevented from being fed too early due to vibration or the like.

  As described above in detail, in the MFP 100 of the present embodiment, the rotating piece 65 of the sheet sensor 62 and the regulating member 78 are interlocked. When the sheet is in contact with the rotating piece 65 and the rotating piece 65 is in the contact position 65B, the restricting member 78 is in the restricting position 78A, and the locking bar 76 is moved from the locking position 761A to the non-locking position 761B. Regulate displacement. In other words, while the presence of a sheet is detected based on the output signal of the sheet sensor 62, the lock bar 76 is not unlocked even if it receives vibration or the like. On the other hand, in a state where the sheet does not contact the rotating piece 65 and the rotating piece 65 is in the non-contact position 65A, the restricting member 78 is in the non-restricting position 78B and is not locked from the locking position 761A of the lock bar 76. The displacement to the position 761B is not restricted. That is, the MFP 100 can start feeding a sheet at a scheduled timing by energizing the solenoid 77 while the absence of the sheet is detected. As a result, during continuous paper feeding, appropriate paper feeding is possible at the paper feeding timing, and unlocking is mechanically suppressed at times other than paper feeding timing, so that the lock is inadvertently released. , Paper feeding at unintended timing is reduced.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the present invention is not limited to an MFP, and can be applied to any printer, copier, scanner, FAX, or the like having a paper feed function. For example, the document reading unit 20 may be omitted. Further, the configuration for forming an image is not limited to the electrophotographic method, and may be an ink jet method. Further, an apparatus capable of color printing or an apparatus only for monochrome printing may be used. Further, for example, the paper feeding device of the present invention can be applied to a transport device that transports a document with a scanner.

  In this embodiment, the solenoid 77 pulls down the end 762 of the lock bar 76 by energization. However, instead of this, for example, as shown in FIG. For example, a configuration may be adopted in which the end portion 762 is pulled up by energization to be locked, and the lock is released by de-energization.

  Further, for example, the stopper 79 may be omitted. However, it is preferable that the stopper 79 is provided because the restriction of the lock bar 76 by the restriction member 78 is ensured. Further, the position of the stopper 79 only needs to restrict the movement of the regulating member 78 from the regulating position 78A to the non-regulating position 78B, and does not have to be in contact with the regulating member 78. Further, the position is not limited to the position illustrated in the present embodiment, and may be the position illustrated in FIG. Further, the stopper 79 may be provided on the rotating piece 65. That is, you may arrange | position so that the excessive rotation of the rotation piece 65 may be restrict | limited.

  In this embodiment, the restricting member 78 is fixed to the rotating shaft 66 of the rotating piece 65. However, the restricting member 78 may be displaced in conjunction even if it is not directly fixed. When the distance between the sheet sensor 62 and the pickup roller 13 is large, or when the moving amount of the rotating piece 65 and the moving amount of the regulating member 78 are different, the displacement is transmitted via, for example, a gear or a pulley. May be.

  Further, the rotation shaft 66 of the regulating member 78 may not be parallel to the rotation shaft 763 of the lock bar 76. For example, a restricting member that rotates and moves in a plane orthogonal to a plane including the movement path of the lock bar 76 may be used. The restricting member may be disposed so as to intersect the moving path of the lock bar 76 at the restricting position and not disposed to intersect the moving path of the lock bar 76 at the non-regulating position.

  Further, the member interlocked with the restricting member 78 may be a member that contacts and displaces the sheet, and is not limited to the rotating piece 65 of the sheet sensor 62. For example, a rotating piece of another sheet sensor may be used. Alternatively, apart from the sheet sensor, a member that contacts and displaces the sheet may be provided, and the regulating member may be interlocked. However, the increase in the number of parts can be suppressed by also using the rotating piece of the sheet sensor.

  The member that interlocks with the regulating member 78 is not limited to the rotating piece 65 of the sheet sensor 62, but abuts against the sheet at a position downstream of the registration roller 15 and upstream of the process unit 11 in the sheet conveyance direction. It is desirable. Since there are cases where a plurality of sheets are conveyed in a state of being overlapped at a position upstream of the registration rollers 15, there is a possibility that appropriate control cannot be performed. In addition, when the member that contacts the sheet downstream of the process unit 11 and the restricting member are interlocked, the state that is not regulated continues until the sheet reaches the contact part. There is a high possibility of misfeeding. In addition, the productivity decreases because the distance between the preceding sheet and the succeeding sheet is too large. That is, when the sheet sensor is also used, it is more preferable to link the rotating piece of the sheet sensor 62 and the regulating member than the sheet sensor 61 or the sheet sensor 63.

DESCRIPTION OF SYMBOLS 10 Image formation part 11 Process part 13 Pickup roller 15 Registration roller 20 Original reading part 22 Image sensor 23 Contact glass 24 ADF
51 Paper Feed Cassette 65 Rotating Piece 71 Missing Gear 76 Lock Bar 77 Solenoid 78 Restricting Member 79 Stopper 100 MFP

Claims (8)

A storage section for storing the seat;
A paper feed roller for carrying in a sheet stored in the storage unit;
Abutting on a sheet carried in by the sheet feeding roller and conveyed in the apparatus, and a sheet abutting position that is displaced between a sheet abutting position that is abutting and a sheet non-abutting position that is not abutting Part,
A paper feed gear for rotating the paper feed roller;
A lock portion that is in contact with the paper feed gear and is displaced between a lock position that locks the rotation of the paper feed gear and an unlock position that does not lock the rotation of the paper feed gear;
The lock unit is connected to the lock unit, and the lock unit is set to a different position between the non-lock position and the lock position when energized and de-energized. A solenoid that moves and unlocks the paper feed gear by the lock;
In conjunction with the sheet contact portion, when the sheet contact portion is in the sheet contact position, the lock portion is in a first position that restricts movement of the lock portion to the unlocked position. , In a state where the sheet contact portion is in the sheet non-contact position, a restriction portion in a second position that is not restricted;
A sheet feeding device comprising: In the paper feeding device according to claim 1,
A sheet feeding device, comprising: a fixing unit that is fixed to the apparatus main body and that restricts movement of the restricting unit at the first position to a side opposite to the second position. The sheet feeding device according to claim 2,
The sheet feeding device, wherein the fixing portion is in contact with the restricting portion in a state where the restricting portion is in the first position. In the paper feeding device according to any one of claims 1 to 3,
A sheet feeding device comprising: a sensor that outputs different signals depending on whether the sheet contact portion is in the sheet contact position or the sheet non-contact position. In the paper feeding device according to any one of claims 1 to 4,
A drawing roller for drawing the sheet carried in by the sheet feeding roller at a predetermined timing;
The sheet feeding device, wherein the sheet abutting portion abuts on the sheet on the downstream side of the drawing roller in the sheet conveying direction. The sheet feeding device according to claim 5,
A process unit that prints an image on the sheet drawn by the drawing roller or reads the image of the sheet;
The sheet feeding device, wherein the sheet abutting portion abuts on the sheet upstream of the process unit in the sheet conveyance direction. A storage section for storing the seat;
A paper feed roller for carrying in a sheet stored in the storage unit;
A printing unit for printing an image on the sheet carried by the paper feed roller;
A sheet contact position that is in contact with and contacted with a sheet that is carried in by the sheet feeding roller and is conveyed through the apparatus toward the printing unit; and a sheet non-contact position that is not in contact A sheet contact portion that is displaced by
A paper feed gear for rotating the paper feed roller;
A lock portion that is in contact with the paper feed gear and is displaced between a lock position that locks the rotation of the paper feed gear and an unlock position that does not lock the rotation of the paper feed gear;
The lock unit is connected to the lock unit, and the lock unit is set to a different position between the non-lock position and the lock position when energized and de-energized. A solenoid that moves and unlocks the paper feed gear by the lock;
In conjunction with the sheet contact portion, when the sheet contact portion is in the sheet contact position, the lock portion is in a first position that restricts movement of the lock portion to the unlocked position. , In a state where the sheet contact portion is in the sheet non-contact position, a restriction portion in a second position that is not restricted;
A printing apparatus comprising: The printing apparatus according to claim 7,
A manuscript table,
A reading unit for reading an image of a document on the document table;
A cover part that is openable and closable with respect to the document table, and that holds the document on the document table in a closed state;
A printing apparatus comprising:

Images