JP3678218B2 - Paper feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a sheet feeding device that separates and feeds stacked sheets of an image forming apparatus such as a printer, a copier, or a facsimile.
[0002]
[Prior art]
  2. Description of the Related Art Conventionally, image forming apparatuses such as laser printers, color ink jet printers, facsimile machines, and copying machines are provided with a paper feeding device for feeding cut sheets one by one to the image forming unit. The sheet feeding device includes a mounting plate on which a plurality of sheets are stacked, a sheet feeding roller that presses and feeds the uppermost sheet of the stacked sheet bundle, and a sheet that has been fed Is provided to the image forming unit. In addition, as disclosed in Japanese Patent Laid-Open No. 10-194501, etc., there are also provided with a stopper that regulates the leading edge of the sheet so that a plurality of sheets stacked on the placing plate are not sloppy into the conveying unit. is there.
[0003]
  In this paper feeding device, when feeding a sheet, the stopper retracts to release the regulation of the sheet bundle, and then the uppermost sheet is fed by the paper feeding roller. Therefore, when feeding paper, it is necessary to perform drive control such that the stopper is retracted and then the paper feed roller is driven. In the prior art, control by a computer is performed in order to link the operation of the stopper and the drive of the paper feed roller. I need. In the technique described in the published patent publication, the operation of the stopper is mechanically interlocked with the conveying roller of the sheet conveying unit, but the feeding roller is controlled using a solenoid separately from the operation control of the stopper. ing.
[0004]
[Problems to be solved by the invention]
  In the above-described conventional apparatus, etc., an actuator such as a solenoid is used for the operation of the stopper or the drive control of the paper feed roller, and further, a control unit for controlling the actuator is required, so that the structure of the apparatus is complicated. There is a problem that the cost is increased.
[0005]
  The present invention has been made to solve this conventional problem, and has an object to provide a paper feeding device that can drive and control the stopper and the paper feeding roller with a low cost and simple configuration. To do.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, a sheet feeding device according to the first aspect of the present invention includes a placing section on which stacked sheets can be placed, a sheet feeding roller that feeds the sheets from the placing section,A separation pad for separating the sheet fed by the paper feed roller;It is possible to move to a restricting position for restricting movement of the sheet in the sheet feeding direction by coming into contact with a leading end in the feeding direction of the stacked sheets and a releasing position for releasing the restriction away from the sheet. A stopper, a driving motor for generating a driving force for operating the paper feed roller and the stopper, and a driving force transmitting means for transmitting a driving force from the driving motor to the paper feeding roller or the stopper, When the driving motor rotates in one direction, the driving force transmission meansThe uppermost sheet among the stacked sheets is separated by the sheet feeding roller and the separation pad. AsA driving force is transmitted to move the stopper to the release position, and when the stopper reaches the release position, the driving force transmission for moving the stopper is interrupted, and the drive motor is moved in the other direction. If it rotatesIn order to prevent other sheets on the placement unit from sagging in the feeding directionA driving force is transmitted so as to move the stopper to the restriction position, and when it reaches the restriction position, a stopper drive switching means for interrupting the driving force transmission for the stopper movement and a rotation to the paper feed roller A sheet feed drive transmission section for transmitting a driving force; and a movable movement transmission section connected to or separated from the sheet feed drive transmission section, and the drive motor rotates in the one direction at the start of sheet feeding In this case, after the stopper is moved from the restriction position to the release position by the stopper drive switching means, the movement transmission unit is connected to the paper feed drive transmission unit to transmit a driving force to the paper feed roller. And a sheet feed drive switching means for separating the movement transmission section from the sheet feed drive section when the drive motor rotates in the other direction and blocking transmission of the drive force to the sheet feed roller. It is an.
[0007]
  According to a second aspect of the present invention, in the paper feeding device according to the first aspect, the stopper drive switching means includes a notch gear, and a stopper drive gear that interlocks the stopper, and a sun gear. And a planetary gear unit having two planetary gears meshed with the sun gear and an arm that holds the planetary gears and is rotatable about the central axis of the sun gear according to the rotation direction of the drive motor. Thus, the notch gear is arranged so as to mesh with one of the planetary gears according to the rotation direction of the drive motor.
[0008]
  According to a third aspect of the present invention, in the paper feeding device according to the second aspect, the stopper drive switching means is configured to release the notch when the meshing between the notch gear and the planetary gear is released. It has a posture holding means for holding the posture of the gear.
[0009]
  According to a fourth aspect of the present invention, there is provided the sheet feeding device according to the fourth aspect of the present invention, a placement unit on which the stacked sheets can be placed, a sheet feed roller that feeds the sheets from the placement unit,A separation pad for separating the sheet fed by the paper feed roller;It is possible to move to a restricting position for restricting movement of the sheet in the sheet feeding direction by coming into contact with a leading end in the feeding direction of the stacked sheets and a releasing position for releasing the restriction away from the sheet. A stopper, a driving motor for generating a driving force for operating the paper feed roller and the stopper, and a driving force transmitting means for transmitting a driving force from the driving motor to the paper feeding roller or the stopper, The driving force transmitting means is arranged so that when the driving motor rotates in one direction, the feeding rollerFor feeding the sheet out of the mounting sectionFeeding drive switching means that cuts off driving force transmission to the feed roller when the drive motor is rotated in the other direction, and a drive force is transmitted when the drive motor is rotated in the one direction. Stopper driving switching that cuts off the driving force for stopper movement and transmits the driving force of the driving motor to move the stopper to the restricting position or the releasing position when the driving motor rotates in the other direction Have meansThe drive motor rotates in the other direction to move the stopper to the release position, and then the drive motor is rotated in one direction so that the stacked sheets are separated and fed by the separation pad. After that, by rotating the drive motor in the other direction again and moving the stopper to the restricting position, other sheets on the placement unit are prevented from sagging in the feeding direction.It is characterized by doing.
[0010]
  According to a fifth aspect of the present invention, in the paper feeding device according to the fourth aspect of the present invention, position detection means for detecting whether the stopper is in the restriction position or the release position, and detection information by the position detection means Rotation control means for controlling the rotation of the drive motor based on the above.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, a preferred embodiment of a paper feeding device of the present invention will be described with reference to the drawings, taking an image forming apparatus having the paper feeding device of the present invention as an example.
[0012]
  First, a first embodiment of a paper feeding device according to the present invention will be described with reference to FIGS.
[0013]
  1 is a perspective view of a multifunctional image forming apparatus equipped with a paper feeding device according to an embodiment of the present invention, FIG. 2 is a perspective view of the paper feeding device, and FIG. 3 is a front view of a main part of the paper feeding device. 4 is a cross-sectional view taken along line VV in FIG. 3, FIG. 5 is an explanatory diagram showing a state when stacked sheets are set in a paper feeder, and FIG. 6 is an explanatory diagram showing a state at the start of paper feeding. 7 is an explanatory view showing the state when the stopper is raised, FIG. 8 is a schematic perspective view showing the shape of the stopper, FIG. 9 is a schematic perspective view showing the shape of the rotating shaft of the stopper moving mechanism, and FIG. FIG. 11 is a schematic diagram of the planetary gear mechanism of the stopper drive switching means, FIG. 12 is a schematic diagram of the notch gear portion, FIG. 13 is a block diagram of the control system of the image forming apparatus, and FIG. It is explanatory drawing which shows the operation state of the drive motor of this embodiment, a paper feed roller, and a stopper.
[0014]
  A multifunction image forming apparatus 1 shown in FIG. 1 has a facsimile function, a printer function, a copying function, a scanner function, and the like. The multifunctional image forming apparatus 1 has a substantially box-shaped main body 2, and an operation panel 3 is disposed on the upper surface of the main body 2. The operation panel 3 is provided with various buttons such as numeric buttons “0” to “9”, a start button, and a function operation button, and various operations are performed by pressing these buttons. A liquid crystal display (LCD) 4 is provided at the rear of the operation panel 3, and a setting state of the image forming apparatus 1 and various operation messages are displayed as necessary.
[0015]
  A rear part of the liquid crystal display 4 is provided with a document placing part 5 for loading and placing a facsimile document transmitted to the other facsimile apparatus during the facsimile function and a document to be copied during the copying function. The document placed on the document placement unit 5 is scanned on the surface of the document by a scanner device 212 (FIG. 13) provided in the main body 2. The document that has been read is discharged to a paper discharge unit 7 provided in the front part of the main body 2 (lower part of the operation panel 3).
[0016]
  A paper feeding device 10 for placing a plurality of sheets (recording paper) P in a stacked state is provided at the rear portion of the document placing portion 5. The sheet P placed on the sheet feeding device 10 is conveyed to a color ink jet type image forming unit 211 (FIG. 13) in the main body 2, and after a predetermined image is printed by the image forming unit 211, the sheet P is discharged. The paper is discharged to the section 6.
[0017]
  Next, the paper feeding device 10 of this embodiment will be described.
[0018]
  As shown in FIGS. 2 and 3, the sheet feeding device 10 includes a frame frame 11, a mounting plate 12 as a storage unit, and a pair of side wall plates 14 a provided on both left and right sides of the mounting plate 12. , 14b and a pair of guide plates 13a, 13b that are arranged on the inner side of the pair of side wall plates 14a, 14b and are movable in the left-right direction with respect to the mounting plate 12.
[0019]
  The mounting plate 12 and the side wall plates 14a and 14b are integrally formed of a synthetic resin material, and the mounting plate 12 can stack and mount a plurality of sheets P that are recording paper. The pair of guide plates 13a and 13b move far and away so as to guide the left and right side edges of the sheet P according to the widthwise dimension of the sheets P stacked therebetween, and the sheet P is moved to the width of the mounting plate 12. It can be set at the center of the direction (left-right direction).
[0020]
  A separation plate 40 having a separation inclined surface 40a is formed at the lower end of the underframe frame 11, and a separation pad 43 is disposed substantially at the center of the separation inclined surface 40a. A pair of movable stoppers 42 are separated and inclined. It arrange | positions so that it can protrude from the opening part 41 provided in the surface 40a.
[0021]
  The separation pad 43 is in contact with the lower edge of the stacked sheets to cut the sheets. Further, the stopper 42 has a shape as shown in FIG. 8, and the upper surface 42a of the stopper 42 is formed of a member having high friction such as urethane rubber or cork rubber to securely hold the stacked sheets P. Has been.
[0022]
  The stopper 42 can be moved up and down horizontally above and below the separation inclined surface 40a, and the upper surface 42a of the stopper 42 protrudes from the separation inclined surface 40a at a restricting position where it comes into contact with the leading edge of the sheet P during the raising and lowering operation. At the release position where the movement restriction of the sheet P is released, the upper surface 42a moves horizontally so as not to protrude from the separation inclined surface 40a.
[0023]
  As shown in FIG. 5, when a plurality of sheets P are set on the mounting plate 12 in a stacked state, the upper surface 42a of the stopper 42 and the lower end edge of the sheet P are in contact with each other while the stopper 42 is in the restricted position. Since the stopper upper surface 42a has high friction, it securely holds the sheet P and prevents the sheet P from flowing in the direction of the arrow A.
[0024]
  On the other hand, as shown in FIG. 6, when the stopper 42 is in the release position, the upper surface 42a of the stopper 42 is separated from the lower edge of the sheet P. It is possible to smoothly feed paper while effectively preventing double feeding.
[0025]
  Next, the stopper moving mechanism 112 in which the stopper 42 moves up and down will be described with reference to FIGS.
[0026]
  As shown in FIG. 4, at the lower rear of the separation plate 40, a rotating shaft 50 is disposed in parallel with the width direction (left-right direction) of the sheet P, and both end portions thereof penetrate the left and right side wall plates 14a, 14b. It is pivotally supported by rotating. As shown in FIG. 9, the rotation shaft 50 includes a columnar base shaft 50 a centering on the rotation center and a cam 50 b fixed so as to be sandwiched between the base shaft 50 a at a position where the stopper 42 is disposed. Consists of.
[0027]
  As shown in FIG. 5, below the stopper 42, a U-shaped portion 44 a formed in an inverted U-shape and an approximately center position of one arm portion of the U-shaped portion 44 a in the direction of the arrow A. A link 44 including an arm portion 44b that extends and forms a convex portion whose middle portion and tip end are bent upward is disposed so as to contact the lower surface of the stopper 42.
[0028]
  The link 44 is locked to the cam 50b at the U-shaped portion 44a, and the link 44 moves back and forth in the direction of the arrow A corresponding to the rotation of the rotation shaft 50. The lower surface 42b of the stopper 42 has a shape having a concave shape at the substantially central portion and the front, and the release position in a state where the concave portion of the lower surface 42b and the convex portion of the arm 44b of the link 44 are engaged. (FIG. 6), the state in which the convex portion of the arm 44b of the link 44 is completely removed from the concave portion of the lower surface 42b of the stopper 42 is the restricting position (FIG. 5). Therefore, when the link 44 moves in the direction of the arrow A, the concave portion of the lower surface 42b of the stopper 42 and the arm portion 44b of the link 44 are engaged, the stopper 42 is lowered, and the link 44 is moved in the direction of the arrow A. When moving in the opposite direction, the engagement between the concave portion and the bent portion of the arm portion 44b is released, and the stopper 42 is pushed up by the convex portion of the arm portion 44b and rises to the restriction position.
[0029]
  Next, driving force transmission means for transmitting the driving force of the driving motor 60 to the paper feed roller 21 and the stopper 42 will be described.
[0030]
  The driving force transmission means includes a stopper drive switching means 120, a paper feed drive switching means 130, a transmission shaft 20 that transmits the drive force from the drive motor 60 to the paper feed drive switching means 130, and the stopper drive switching means 120. It consists of a stopper moving mechanism 112 that transmits driving force and moves the stopper 42 up and down.
[0031]
  The paper feed roller unit 22 provided with the paper feed drive switching means 130 will be described with reference to FIGS.
[0032]
  Between the left and right side wall plates 14a and 14b, a transmission shaft 20 is pivotally supported at an appropriate distance upward from the upper surface of the separation plate 40, and a middle portion of the transmission shaft 20, that is, At the center in the width direction (left-right direction) of the sheet P, a case 24 of a paper feed roller unit 22 having a paper feed roller 21 as a paper feed means is mounted so as to be rotatable only about the axis of the transmission shaft 20. Yes.
[0033]
  In the case 24 of the paper feed roller unit 22, a drive gear 25 that rotates integrally with the transmission shaft 20 and a tip of an arm 26 that is rotatably covered with the transmission shaft 20 are pivotally supported, and the drive gear 25, a planetary gear 27 that is a movement transmission unit that meshes with 25, an intermediate gear 28 that is a paper feed drive transmission unit, and a gear 29 that meshes with the intermediate gear 28 and rotates integrally with the paper feed roller 21.
[0034]
  The arm 26 has a restricting portion 26 a that restricts the rotation range thereof, and restricts the planetary gear 27 from contacting the case 24. The case 24 is elastically biased by a torsion spring 30 fitted on the transmission shaft 20 so that the paper feed roller 21 is pressed against the uppermost surface of the stacked sheets P.
[0035]
  Next, the stopper drive switching means 120 that transmits the driving force from the drive motor 60 to the stopper moving mechanism 112 will be described with reference to FIGS.
[0036]
  As shown in FIG. 10A, the stopper drive switching means 120 is fixed to the notch gear portion 108, the stopper drive gear 105 fixed to the side end of the rotating shaft 50, and the drive motor 60. A sun gear 124 meshed with the drive gear 61, two planetary gears 125a, 125b meshed with the sun gear 124, and an arm that holds the planet gears and is rotatably fitted to the sun gear 124 126 a, a gear 106 that meshes with the sun gear 124, and a gear 107 that meshes with the gear 106 and is fixed to the transmission shaft 20.
[0037]
  FIG. 11A is a front view of the sun gear 124 and the planetary gears 125a and 125b. Moreover, FIG.11 (b) is the side view seen from the arrow B direction in Fig.11 (a). The planetary gears 125a and 125b are pivotally supported on both arms of the arm 126a, respectively, and mesh with the sun gear 124 to perform planetary motion.
[0038]
  As shown in FIGS. 12 (a) and 12 (b), the notch gear portion 108 overlaps the notch gears 108a and 108b having notches in part so that the notches are shifted by a predetermined angle. Are integrally formed. A contact member 108d is attached to the side surface of the notch gear 108a, and a locking bar 108c for engaging the posture holding spring 129 is provided to protrude from the side surface of the notch gear 108b.
[0039]
  As shown in FIG. 12 (c), the side wall plate 14d is provided with a locking rod 122 for locking the posture holding spring 129, and is in contact with the abutting member 108d to thereby provide a notch gear. Restriction members 123a and 123b for restricting the rotation range of the portion 108 are projected. The locking rod 108c and the locking rod 122 are locked by the posture holding spring 129, and are given an elastic force in a direction approaching each other.
[0040]
  The notch gear portion 108 is transmitted with a driving force from the drive motor 60 when meshed with the planetary gear 125a or 125b. When the notch gear portion 108 is rotated by a certain amount, the notch gear portion 108 is engaged by the notch portion. Canceled.
[0041]
  At this time, the notch gear portion 108 tries to further rotate due to the elastic force of the posture holding spring 129, but the rotation is stopped by the contact member 108 d coming into contact with the regulating member 123 a or 123 b, and the posture holding spring 129. The shape is pressed by elastic force.
[0042]
  Accordingly, when the drive motor 60 rotates clockwise, the cutout portions of the planetary gear 125a and the cutout gear 108a are not opposed to each other in the state shown in FIG. Power is transmitted to the gear 105 to drive the stopper 42. Then, the state shown in FIG. 10B is established, and the meshing between the planetary gear 125a and the notch gear 108a is released, and the power transmission to the stopper 42 and the stopper driving gear 105 is released.
[0043]
  Similarly, when the drive motor 60 rotates counterclockwise, the planetary gear 125b and the cutout portion of the cutout gear 108b do not face each other in the state shown in FIG. 10C, so the cutout gear 108b, Power is transmitted to the stopper drive gear 105 to drive the stopper 42. When the notch gear 108b rotates to the state shown in FIG. 10D, the meshing with the planetary gear 125b is released, and the power transmission to the stopper drive gear 105 is released.
[0044]
  The sheet feeding operation of the sheet P in the sheet feeding device 10 of the present embodiment having the above configuration will be described.
[0045]
  A control system of the image forming apparatus 1 in the present embodiment will be described. FIG. 13 is a block diagram of a control system of the image forming apparatus 1 in the present embodiment.
[0046]
  The control unit of the image forming apparatus 1 according to the present embodiment includes a CPU 201, a ROM 202, a RAM 203, and an input / output interface 204. The CPU 201 executes various controls / calculations, and the ROM 202 stores a control program that instructs various control operations. The RAM 203 is a temporary storage memory that is partially used as a reception buffer memory.
[0047]
  The operation panel 3, the liquid crystal display 4, the modem 210, the image forming unit 211, the scanner device 212, the sheet conveying unit 213, and the paper feeding device 10 provided in the image forming apparatus 1 are connected to the input / output interface 204. Controlled by the CPU 201 via the input / output interface 204.
[0048]
  The paper feeding device 10 is provided with a motor driver 220 that controls the driving of the driving motor 60, and rotates the driving motor in both forward and reverse directions according to a signal from the CPU 201. Further, in the case of a paper feeding apparatus having a detection sensor 128 that detects whether the stopper 42 is in the restriction position or the release position, the detection signal CS of the detection sensor 128 can be output to the CPU 201.
[0049]
  Next, the operation of the stopper drive switching means 120 during paper feeding will be described.
[0050]
  At the time of paper feed standby in which the sheet P placed on the placement plate 12 is not fed, the stopper 42 is in a restricting position for restricting the stacked sheets P (FIG. 5).
[0051]
  When feeding is started, first, the motor driver 220 rotates the drive motor 60 in the normal direction (rotates clockwise in FIG. 10A) by a signal from the CPU 201, thereby driving the sun gear 124 of the stopper drive switching means 120 to drive it. The force is transmitted and the sun gear 124 rotates counterclockwise. As a result, the planetary gear 125a meshed with the sun gear 124 meshes with the notch gear 108a, the notch gear portion 108 rotates counterclockwise, and the stopper drive gear 105 rotates clockwise.
[0052]
  When the stopper driving gear 105 rotates clockwise, the stopper moving mechanism 112 interlocked with the stopper driving gear 105 operates, and the stopper 42 moves from the restriction position to a release position that is separated from the leading edge of the sheet P.
[0053]
  At the timing when the stopper 42 reaches the release position, the notch portion of the notch gear 108a rotates to the meshing position with the planetary gear 125a, where the meshing of both gears is released (FIG. 10 (b)). Since the driving force of the drive motor 60 is not transmitted to the stopper moving mechanism 112, the stopper 42 stops at the release position.
[0054]
  Here, the notch gear portion 108 is held in its attitude by the attitude holding spring 129, the contact member 108d, and the regulating member 123a, and the notch gear 108a meshes with the planetary gear 125a at a timing other than a predetermined timing due to vibration or the like. Can be prevented.
[0055]
  Next, the operation of the paper feed drive switching unit 130 at the start of paper feed will be described.
[0056]
  At the time of waiting for paper feed, the planetary gear 27 of the paper feed drive switching means 130 is held at a position separated from the intermediate gear 28 as shown in FIG. At the start of paper feeding, the drive motor 60 rotates forward (rotates clockwise), and the sun gear 25 rotates counterclockwise via the sun gear 124, the gears 106 and 107, and the transmission shaft 20. When the sun gear 25 rotates counterclockwise, the planetary gear 27 rotates to the intermediate gear 28 side, and the planetary gear 27 and the intermediate gear 28 mesh.
[0057]
  At this time, the rotational distance of the planetary gear 27 is adjusted so that the planetary gear 27 and the intermediate gear 28 mesh after the stopper 42 reaches the release position.
[0058]
  As shown in FIG. 6, the driving force of the driving motor 60 transmitted to the intermediate gear 28 is transmitted to the sheet feeding roller 21, and the sheet P stacked on the mounting plate 12 by the sheet feeding roller 21 rotating clockwise. The top position of is sent out.
[0059]
  Next, the operation of the stopper drive switching unit 120 when the sheet P sent out from the placing plate 12 reaches the sheet conveying unit 213 on the image forming apparatus main body side (at the end of paper feeding) will be described.
[0060]
  At the end of paper feeding, the motor driver rotates the drive motor 60 in the reverse direction (rotates counterclockwise in FIG. 10C) in response to a signal from the CPU 201, whereby the sun gear 124 rotates clockwise. Thereby, the planetary gear 125a meshed with the sun gear 124 is separated from the notch gear 108a, while the planetary gear 125b meshes with the notch gear 108b.
[0061]
  Therefore, the driving force of the driving motor 60 is transmitted to the stopper driving gear 105 via the planetary gear 125b and the notch gear 108b, and the stopper driving gear 105 rotates counterclockwise.
[0062]
  When the stopper driving gear 105 rotates counterclockwise, the stopper 42 is controlled from the release position by the stopper moving mechanism 112 via the rotation shaft 50 fixed to the stopper driving gear 105. It moves to the restriction position (FIG. 7).
[0063]
  At the timing when the stopper 42 reaches the regulation position, the notch portion of the notch gear 108b rotates to the meshing position with the planetary gear 125b, where the meshing of both gears is released (FIG. 10 (d)). Since the driving force of the driving motor 60 is not transmitted to the stopper moving mechanism 112, the stopper 42 stops at the restricting position.
[0064]
  Here, the notch gear portion 108 is held in its attitude by the attitude holding spring 129, the contact member 108d, and the regulating member 123b, and the notch gear 108b meshes with the planetary gear 125b at a timing other than a predetermined timing due to vibration or the like. Can be prevented.
[0065]
  Next, the operation of the paper feed drive switching unit 130 at the end of paper feed will be described.
[0066]
  As shown in FIG. 7, at the end of paper feeding, the motor driver 220 reverses (rotates counterclockwise) the driving motor 60 by a signal from the CPU 201, and the driving force is the sun gear 124, gears 106, 107, This is transmitted through the transmission shaft 20 so as to rotate the sun gear 25 of the paper feed drive switching means 130 clockwise. When the sun gear 25 rotates in the clockwise direction, the planetary gear 27 is separated from the intermediate gear 28, and the paper feed roller is free to rotate.
[0067]
  Therefore, at the end of paper feeding, the driving motor 60 rotates in the direction opposite to the paper feeding direction, and the driving force is not transmitted to the paper feeding roller 21 by the action of the driving force transmitting means, and the stopper 42 is in the restricted position And the leading edge of the sheet P is regulated, so that the sheet P can be effectively prevented from flowing into the image forming apparatus main body side.
[0068]
  The operation of the sheet feeding device according to the present embodiment has been described above. The operations of the drive motor 60, the sheet feeding roller 21, and the stopper 42 will be described with reference to FIG. FIG. 14 is a diagram showing the operating states of the drive motor 60, the paper feed roller 21, and the stopper 42.
[0069]
  In the paper feed standby state, the stopper 42 is in the restriction position ((1)). When the drive motor 60 rotates forward at the start of paper feeding, the stopper 42 descends and stops at the release position ((2)). Immediately after that, the sheet feeding roller 21 is driven to feed the uppermost sheet P stacked and placed ((3)). When the sheet P reaches the sheet conveying section on the image forming apparatus main body side, the CPU 201 stops the drive motor 60 and the paper feed roller 21 ((4)). Thereafter, the drive motor is reversely rotated, and accordingly, the stopper 42 is raised from the release position to the restriction position ((5)).
[0070]
  As described above, in the sheet feeding device of the present embodiment, the sheet feeding roller 21 and the stopper 42 can be driven by one driving motor by the driving force transmitting means. Further, with such a configuration, it is possible to control the operation of the stopper 42 only by controlling the rotation direction without controlling the rotation amount of the drive motor 60.
[0071]
  In the present embodiment, the notch gear portion 108 is formed by integrally forming two notch gears having a notch in a part thereof, but the notch gear portion 108 has a notch in part. You may comprise one notch gear.
[0072]
  Next, a second embodiment of the paper feeding device according to the present invention will be described with reference to FIG. FIG. 15 is a schematic diagram for explaining the stopper drive switching means 120 in the second embodiment. The sheet feeding device 10 of the second embodiment is obtained by changing the configuration of the stopper drive switching unit 120 of the first embodiment, and a description of matters overlapping with the configuration of the first embodiment is omitted. .
[0073]
  As shown in FIG. 15A, the stopper drive switching means 120 includes a stopper drive gear 105 fixed to the rotating shaft 50 interlocked with the stopper moving mechanism 112, and a sensor cam fixed to the stopper drive gear 105. 105 a, a sun gear 124 meshed with the drive gear 61 fixed to the drive motor 60, a planetary gear 125 c meshed with the sun gear 124, and the planetary gear 125 c are held and rotated by the sun gear 124. The arm 126b that can be fitted, the gear 106 that meshes with the sun gear 124, and the gear 107 that meshes with the gear 106 and is fixed to the transmission shaft 20.
[0074]
  Further, when the planetary gear 125c rotates around the rotation axis of the sun gear 124, a regulating member 127 is provided that contacts the arm 126c and regulates the rotation range of the planetary gear 125c.
[0075]
  Furthermore, a detection sensor 128 for detecting the rotational position of the sensor cam 105a fixed to the stopper drive gear 105 is provided as a detection means for detecting whether the stopper 42 is in the restriction position or the release position. The detection sensor 128 has a sensor probe 128a. The detection sensor 128 is in a state (OFF) where the sensor probe 128a is not pushed by the sensor cam 105a when the stopper 42 is in the restriction position. On the other hand, when the stopper 42 is in the release position, the sensor probe 128a is pressed (ON) by the sensor cam 105a. The detection sensor 128 outputs to the CPU 201 as a detection signal CS whether the state is “ON” or “OFF” when the state is switched.
[0076]
  In the sheet feeding device 10 according to the second embodiment having the above-described configuration, the operation of the stopper drive switching unit 120 at the start of sheet feeding for feeding the sheet P placed on the placing plate 12 will be described. To do.
[0077]
  At the time of paper feed standby in which the sheet P placed on the placement plate 12 is not fed, the stopper 42 is in a regulation position for regulating the stacked sheets P, and the detection sensor 128 is in the “OFF” state. is there. Further, the planetary gear 125c is in a position to mesh with the stopper drive gear 105. At the start of paper feeding, the drive motor 60 rotates in the reverse direction (rotates counterclockwise) in FIG. 15A, and the driving force is transmitted to the sun gear 124 of the stopper drive switching means 120, and the stopper is transmitted via the planetary gear 125c. The drive gear 105 rotates clockwise.
[0078]
  When the stopper driving gear 105 rotates clockwise, the stopper moving mechanism 112 interlocked with the stopper driving gear 105 operates to move the stopper 42 from the restriction position to a release position that is separated from the leading edge of the sheet P. At the timing when the stopper 42 reaches the release position, the sensor probe 128a is pushed by the sensor cam 105a, and the detection sensor 128 outputs a detection signal CS “ON” to the CPU 201.
[0079]
  When the CPU 201 receives the detection signal CS, the CPU 201 outputs to the motor driver 220 a signal for causing the drive motor 60 to rotate forward (clockwise). As a result, the drive motor 60 rotates in the forward direction, and the paper feed roller 21 is driven, as in the first embodiment, to feed out the uppermost sheet P placed on the placement plate 12. On the other hand, as shown in FIG. 15B, the planetary gear 125c of the stopper drive switching means 120 is separated from the stopper drive gear 105, and the driving force of the drive motor 60 is not transmitted to the stopper moving mechanism 112, so that the stopper 42 is released. Stop at position.
[0080]
  Next, the operation of the stopper drive switching unit 120 when the sheet P sent out from the placing plate 12 reaches the sheet conveying unit 213 on the image forming apparatus main body side (at the end of paper feeding) will be described.
[0081]
  At the end of paper feeding, the motor driver 220 reversely rotates the drive motor 60 again (rotates counterclockwise) by a signal from the CPU 201, and the separated planetary gear 125 c meshes with the stopper drive gear 105. Accordingly, the stopper driving gear 105 rotates, and the stopper moving mechanism 112 moves the stopper 42 from the release position to the restriction position.
[0082]
  Here, at the timing when the stopper 42 reaches the regulation position, the detection sensor 128 switches from ON to OFF, and outputs a detection signal CS “OFF” to the CPU 201. When receiving the detection signal CS, the CPU 201 outputs a signal for stopping the drive motor 60, the drive motor 60 is stopped, and the stopper 42 is stopped at the release position.
[0083]
  FIG. 16 is a schematic diagram showing a modification of the stopper drive switching means of the second embodiment. In the second embodiment, the stopper drive switching means 120 may be configured without the gear 106 and the regulating member 127 as shown in FIG. In this example, it is possible for the paper feed drive switching means 130 to switch the driving force transmission to the paper feed roller 21 without using a planetary gear mechanism, and the number of parts is reduced compared to the configuration of the second embodiment. Therefore, the driving force transmission means can be configured with a very simple configuration.
[0084]
  The operation of the sheet feeding device 10 according to the second embodiment has been described above. The operations of the drive motor 60, the sheet feeding roller 21, the detection sensor 128, and the stopper 42 will be described with reference to FIG. FIG. 17 is an explanatory diagram illustrating operation states of the drive motor 60, the paper feed roller 21, the detection sensor 128, and the stopper 42 in the second embodiment.
[0085]
  In the paper supply standby state, the stopper 42 is in the restriction position, and the detection sensor 128 is in the “OFF” state ((1)). When the drive motor 60 rotates reversely at the start of paper feeding, the stopper 42 descends and stops at the release position ((2)). At this time, the detection sensor 128 is switched to the “ON” state ((3)). Thereafter, the drive motor 60 rotates in the forward direction, and the sheet feeding roller 21 is driven accordingly, and the uppermost sheet P stacked and loaded is sent out (4). When the sheet P reaches the sheet conveying section on the image forming apparatus main body side, the CPU 201 stops the drive motor 60 and the paper feed roller 21 ((5)). Thereafter, the drive motor is reversely rotated again, and the stopper 42 is raised and stopped at the restriction position ((6)). At this time, the detection sensor 128 is switched to the “OFF” state (7).
[0086]
  As described above, in the sheet feeding device 10 according to the second embodiment, the driving of the sheet feeding roller 21 and the movement of the stopper 42 can be separated by switching between forward and reverse rotation of the drive motor 60. As a result, the stopper 42 can be moved up and down during paper feeding or conveyance, so that double feeding of paper can be prevented and time for continuous paper feeding can be shortened. Further, when the drive motor 60 is reversely rotated due to the stopper movement, the driving force of the drive motor 60 is not transmitted to the paper feed roller 21 by the paper feed drive switching means 130, so the speed at which the stopper 42 is moved is arbitrarily set. You can control and select the most suitable control for paper feed.
[0087]
  Although the paper feeding device of the present invention has been described above, the present invention is not limited to the above-described embodiment, and is within the scope of the technical idea of the present invention and is obvious to those skilled in the art. Various changes can be made based on the above.
[0088]
  For example, in this embodiment, the rotating shaft 50 and the link 44 are used to raise and lower the stopper 42. However, a mechanism that can raise and lower the stopper 42 is not necessarily required. A mechanism may be provided in which a cam having a protruding portion is provided directly below and the stopper 42 is moved up and down by rotating the cam.
[0089]
  In the first embodiment, the spring is used as the posture holding means for holding the posture of the notched gear portion 108, but it may be used instead as long as it is an elastic member having the same effect. Further, the posture holding means is formed in a protruding shape, for example, so that the abutting member 108d of the notch gear 108b reaches the vicinity of the side wall plate 14b of the paper feeding device 10. Then, by forming a recess that meshes with the abutting member 108d in the side wall plate 14b at a position where the meshing between the notch gear portion 108 and the planetary gears 125a and 125b is released, It is possible to hold the posture of the notch gear portion 108 by combining the recesses. At this time, the strength of the engagement between the contact member 108d and the recess does not come off by vibration, and when the driving force of the drive motor 60 is transmitted to the notch gear portion 108, the contact member 108d is easily removed from the recess. It is desirable to be strong enough to come off.
[0090]
【The invention's effect】
  As described above, the sheet feeding device of the invention according to claim 1 isWhen setting multiple sheets on the mounting plate in a stacked state,It has a movable stopper that abuts the leading edge of the stacked sheets in the feeding direction and restricts the sheet from sagging in the feeding direction. Drive the paper feed rollerAs a result, the uppermost sheet among the stacked sheets is separated by the separation pad and sent out.,Of this sent out sheetAt the end of paper feeding, use the stopper againOthers that are stacked on the mounting plateSheetAvalancheHigh-cost parts such as another drive motor and solenoid for moving the stopper can be performed by controlling the forward / reverse rotation of one drive motor. In addition, there is an effect that the productivity can be improved and the size of the apparatus can be reduced by simplifying the process when assembling the apparatus.
[0091]
  According to a second aspect of the present invention, in the paper feeding device according to the first aspect, in the mechanism for transmitting the driving force of the driving motor to the stopper, the stopper has a simple configuration using a planetary gear and a notch gear. Since the movement of the stopper can be controlled without using a sensor or the like for detecting the restriction position and the release position, the effect of reducing the cost and improving the productivity by simplifying the process at the time of assembling the apparatus is achieved.
[0092]
  Further, according to a third aspect of the present invention, in the paper feeding device according to the second aspect, the notch gear and the planetary gear are provided by the notch portion by providing posture holding means for holding the posture of the notch gear. When the meshing is released, the notch gear and the planetary gear, which are released from meshing, are reengaged by the vibration of the apparatus or the force by which the stacked sheets push the stopper, so that the stopper is not at a predetermined timing. There exists an effect that it can prevent moving.
[0093]
  In the sheet feeding device according to the fourth aspect of the present invention, the driving of the sheet feeding roller and the movement of the stopper can be performed separately by switching the forward / reverse rotation of the drive motor. However, the stopper can be moved to prevent double feeding of sheets, and the time for continuous feeding can be shortened. Also, when the drive motor is rotating in reverse because of the stopper movement, the drive force of the drive motor is not transmitted to the paper feed roller by the paper feed drive switching means, so the speed at which the stopper is moved can be controlled, making it ideal for paper feed. There is an effect that the control can be selected.
[0094]
  According to a fifth aspect of the present invention, in the paper feeding device according to the fourth aspect, the position detecting means for detecting the position of the stopper, and the means for controlling the rotation of the drive motor based on the information of the position detecting means. By providing this, it is possible to stop the stopper at an appropriate position, and it is possible to prevent the sagging of the sheets stacked and placed on the placement portion.
[Brief description of the drawings]
FIG. 1 is a perspective view of an image forming apparatus.
FIG. 2 is a perspective view of a sheet feeding device.
FIG. 3 is a front view of a main part of the paper feeding device.
4 is a cross-sectional view taken along line VV in FIG. 3;
FIG. 5 is an explanatory diagram illustrating a state when stacked sheets P are set in a sheet feeding device.
FIG. 6 is an explanatory diagram showing a state at the start of paper feeding.
FIG. 7 is an explanatory diagram showing a state when the stopper is raised.
FIG. 8 is a schematic perspective view showing a shape of a stopper.
FIG. 9 is a schematic perspective view showing a shape of a rotation shaft of a stopper moving mechanism.
FIG. 10 is a schematic diagram of stopper drive switching means of the first embodiment.
FIG. 11 is a schematic view of a planetary gear mechanism of stopper drive switching means.
FIG. 12 is a schematic view of a notch gear portion.
FIG. 13 is a block diagram of a control system of the image forming apparatus.
FIG. 14 is an explanatory diagram illustrating operations of a drive motor, a paper feed roller, and a stopper according to the first embodiment.
FIG. 15 is a schematic view of stopper drive switching means of the second embodiment.
FIG. 16 is a schematic view of a modified example of the stopper drive switching means of the second embodiment.
FIG. 17 is an explanatory diagram illustrating operations of a drive motor, a paper feed roller, a detection sensor, and a stopper according to the second embodiment.
[Explanation of symbols]
1 Image forming device
10 Paper feeder
12 Mounting plate
21 Paper feed roller
42 Stopper
60 Drive motor
108 Notch gear
120 Stopper drive switching means
128 detection sensor
129 Posture holding spring
130 Paper feed drive switching means

Claims (5)

A stacking unit on which the stacked sheets can be mounted; a sheet feeding roller that feeds the sheet from the placing unit; a separation pad that separates the sheets fed by the sheet feeding roller; A stopper that is in contact with the leading edge in the sheet feeding direction and restricts movement of the sheet in the sheet feeding direction; and a stopper that is movable away from the sheet to a release position that releases the restriction; and A driving motor for generating a driving force for operating the roller and the stopper; and a driving force transmitting means for transmitting the driving force from the driving motor to the paper feed roller or the stopper;
The driving force transmission means is
When the drive motor rotates in one direction, the stopper is moved to the release position so that the uppermost sheet among the stacked sheets is separated by the sheet feeding roller and the separation pad. transmits a driving force so as to, and when the stopper has reached the release position, blocks the transmission of the driving force for said stopper moving, when the driving motor is rotated in the other direction, the placement In order to prevent other sheets on the part from sagging in the feeding direction, a driving force is transmitted to move the stopper to the restriction position, and when the stopper reaches the restriction position, the stopper Stopper drive switching means for interrupting transmission of driving force for movement,
A sheet feeding drive transmission unit for transmitting a rotational driving force to the sheet feeding roller; and a movable movement transmission unit connected to or separated from the sheet feeding drive transmission unit. In the case of rotation in the one direction, after the stopper is moved from the restriction position to the release position by the stopper drive switching means, the movement transmission unit is connected to the paper feed drive transmission unit and the paper feed roller Paper feed drive switching means for transmitting the drive force to the paper feed roller and when the drive motor rotates in the other direction, the movement transmission portion is separated from the paper feed drive portion to interrupt the transmission of the drive force to the paper feed roller. And a sheet feeding device.   The stopper drive switching means is constituted by a notch gear, and a stopper drive gear interlocked with the stopper, a sun gear, two planet gears meshing with the sun gear, and holding these planet gears, And a planetary gear unit having an arm that is rotatable about the central axis of the sun gear according to the rotation direction, and the notch gear is one of the planetary gears according to the rotation direction of the drive motor. The sheet feeding device according to claim 1, wherein the sheet feeding device is arranged to mesh with the sheet feeding device.   3. The supply according to claim 2, wherein the stopper drive switching unit includes a posture holding unit that holds a posture of the notch gear when the meshing between the notch gear and the planetary gear is released. Paper device. A stacking unit on which the stacked sheets can be mounted; a sheet feeding roller that feeds the sheet from the placing unit; a separation pad that separates the sheets fed by the sheet feeding roller; A stopper that is in contact with the leading edge in the sheet feeding direction and restricts movement of the sheet in the sheet feeding direction; and a stopper that is movable away from the sheet to a release position that releases the restriction; and A driving motor for generating a driving force for operating the roller and the stopper; and a driving force transmitting means for transmitting the driving force from the driving motor to the paper feed roller or the stopper;
The driving force transmission means is
When the drive motor rotates in one direction, a driving force for feeding the sheet from the placement unit is transmitted to the paper feed roller, and to the paper feed roller when the drive motor rotates in the other direction. Paper feed drive switching means for cutting off the drive force transmission of
When the drive motor rotates in the one direction, the driving force for moving the stopper is cut off, and when the drive motor rotates in the other direction, the stopper is moved to the restriction position or the release position. the driving force of the driving motor have a stopper driving switching unit for transmitting to,
After the drive motor rotates in the other direction and moves the stopper to the release position, the drive motor is rotated in one direction and the stacked sheets are separated and fed by the separation pad, Rotating the drive motor in the other direction again to move the stopper to the restricting position prevents other sheets on the placement unit from sagging in the feeding direction. .   It has a position detection means for detecting whether the stopper is in a restriction position or a release position, and a rotation control means for controlling the rotation of the drive motor based on detection information by the position detection means. The sheet feeding device according to claim 4.

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