JP2006315833A - Sheet feeding device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeding device and an image forming device whose device bodies are compact, even when a sheet separating means is disposed to a sheet loading means and a sheet feeding means is disposed to the device body. <P>SOLUTION: The sheet separating means 8b frictionally separates sheets one by one abutted with and fed by the sheet feeding means. The sheet separating means 8b is supported to be movable between a first position where the sheet separating means can be press-contact with the sheet feeding means and a second position where the sheet separating means is separated from the sheet feeding means, by the sheet loading means 2 detachable to the device body in a direction intersecting with a sheet feeding direction. When the sheet loading means 2 is installed, an abutting means disposed to the device body moves the seat separating means to the first position, and while the sheet loading means 2 is inserted into or drawn out of the device body, a guide means disposed to the device body moves the seat separating means from the second position toward the first position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet feeding apparatus and an image forming apparatus, and more particularly to a sheet stacking unit provided with a sheet separating unit.

  2. Description of the Related Art Conventionally, an electrophotographic or electrostatic recording type image forming apparatus such as a copying machine, a laser beam printer (LBP), a facsimile or the like includes a sheet feeding device that feeds a sheet to an image forming unit. Thus, the sheets stacked in the sheet feeding cassette as the sheet stacking unit are sequentially fed to the image forming unit, and the image forming unit forms an image on the sheet.

  By the way, as a sheet feeding method of such a conventional sheet feeding apparatus, a Duplo sheet feeding method using a separation pad, a retard sheet feeding method using a retard roller, and a separation roller sheet feeding method using a separation roller (simple There are various paper feeding methods such as a retard paper feeding method.

  Here, the Duplo paper feeding method is to separate the sheets by attaching the separation pad to the paper feeding cassette that is inserted and removed in the same direction as the sheet conveying direction, and the cost is very low. Used in low-priced machines. The retard paper feeding method is a paper feeding method with high cost and paper feeding performance, and is mainly used in high speed machines, copiers, MFPs, and the like. This retard paper feeding method is used for a cassette that is inserted and removed substantially at right angles to the sheet conveying direction. Further, the separation roller sheet feeding method is a sheet feeding method having an intermediate cost and sheet feeding performance.

  By the way, in such a sheet feeding apparatus that separates and feeds sheets by the sheet feeding method, when the sheet feeding cassette is attached and detached in a direction substantially perpendicular to the sheet feeding direction, when the sheet feeding cassette is inserted and removed. Therefore, it is necessary to release the friction between the sheet feeding means for feeding the sheets stacked in the sheet feeding cassette and the sheet.

  This is because when the friction between the sheet feeding unit and the sheet occurs, the stacked sheets are pulled out of a predetermined position. Also, depending on the case, the stacked sheets become crisp and become a great resistance to the operation of attaching and detaching the paper feed cassette, and the sheets are also lost.

  Therefore, in order to solve such a problem, there is a configuration in which the sheet feeding unit and the sheet separating unit are separated from each other when the sheet stacking unit detachable in a direction substantially perpendicular to the sheet conveying direction is attached or detached. It has been proposed (see, for example, Patent Document 1).

JP 09-67029 A

  However, such conventional sheet feeding apparatus and image forming apparatus have the following problems.

  That is, since the Duplo paper feeding method and the separation roller paper feeding method are basically to insert and remove the paper feeding cassette in the same direction as the sheet conveying direction, the paper feeding cassette is substantially perpendicular to the sheet conveying direction. In the case of attaching and detaching in the direction, the sheet feeding means and the separation pad or the separation roller are arranged in the paper feed cassette, or the sheet feeding means and the separation pad or the separation roller are arranged in the apparatus main body. .

  However, when the sheet feeding means and the separation pad or separation roller are arranged in the sheet feeding cassette in this way, it is difficult to replenish the sheet in the sheet feeding cassette, or when the sheet feeding unit and the separation pad or separation roller are arranged in the apparatus main body It is troublesome to replace parts such as a paper feed roller, a separation roller, and a separation pad.

  In order to avoid these problems, a configuration in which the sheet feeding unit is left in the apparatus main body and the sheet separating unit is arranged in the sheet feeding cassette is conceivable. In such a configuration, the sheet feeding cassette is mounted. In this case, it is necessary to provide a retreat mechanism for retracting the separation pad or the sheet separation means using the separation roller so that the sheet feeding means does not collide with the separation pad or the separation roller.

  However, since it is difficult to provide such a retracting mechanism in the paper feed cassette, it is provided in the apparatus main body. However, if the retracting mechanism is provided in the apparatus main body in this way, the size of the apparatus main body increases. Problem arises.

  Therefore, the present invention has been made in view of such a situation, and even when the sheet separating unit is disposed in the sheet feeding cassette (sheet stacking unit) and the sheet feeding unit is disposed in the apparatus body, the apparatus body is not provided. An object of the present invention is to provide a sheet feeding apparatus and an image forming apparatus that can be made compact.

  The present invention provides a sheet stacking unit that is detachable in a direction crossing a sheet feeding direction with respect to the apparatus main body, and a sheet feeding unit that is provided in the apparatus main body and that feeds the sheets stacked on the sheet stacking unit. And a sheet separating unit that is attached to the sheet stacking unit and separates the fed sheets in contact with the sheet feeding unit one by one. The apparatus is movably supported between a first position that can be pressed against the sheet feeding means and a second position that is separated from the sheet feeding means, and the sheet stacking means is mounted on the apparatus main body. A contact means for moving the sheet separating means to the first position is sometimes provided, and the sheet separating means is moved from the second position while the sheet stacking means is being inserted into or pulled out from the apparatus main body. In which it characterized in that a guide means for moving in the serial direction of the first position.

  As in the present invention, a sheet separating unit supported movably between a first position that can be pressed against the sheet feeding unit by the sheet stacking unit and a second position that is separated from the sheet feeding unit, When the sheet stacking means is mounted, it is moved to the first position by the contact means provided on the apparatus main body, and the second position is set by the guide means provided on the apparatus main body while the sheet stacking means is being inserted or pulled out. To the first position. As a result, even when the sheet separating unit is disposed on the sheet stacking unit and the sheet feeding unit is disposed on the apparatus main body, the apparatus main body can be made compact.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus including a sheet feeding device according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes an apparatus main body, and 2 (2 a, 2 b) a sheet feeding cassette which is a sheet stacking means for stacking and storing sheets. The sheet feeding cassette 2 is configured to be detachable from the apparatus main body 1. Yes. In the present embodiment, the paper feed cassette 2 is mounted on the apparatus main body 1 in two upper and lower stages.

  FIG. 2 is a view showing the inside of the sheet feeding cassette 2, and in FIG. 2, 3 is a middle plate that is a sheet stacking plate that can be rotated in the vertical direction, and sheets are stacked on the middle plate 3. Reference numerals 4 and 5 denote a side guide front unit and a side guide rear unit that regulate the position of the seat in the left-right direction (vertical direction in the figure). These side guide front unit 4 and side guide rear unit 5 are respectively seats. The side guide front 4a and the side guide rear 5a are provided.

  FIG. 3 is a view showing a state in which the intermediate plate 3 is removed from the paper feed cassette 2. In FIG. 3, 4b is a side rack front assembled in a direction perpendicular to the side guide front 4a. A rack gear is formed on the front side rack 4b. Reference numeral 5b denotes a side rack rear 5b that is assembled in a direction perpendicular to the side guide rear 5a provided to face the side guide front 4a. A rack gear is formed on the rear rack 5b. Reference numeral 6 denotes a pinion gear that meshes with rack gears provided on the front side rack 4b and the rear side rack 5b, and the side guide front unit 4 and the side guide rear unit 5 are interlocked with each other via the pinion gear 6.

  4c is a side guide handle that is pinched when the side guide front unit 4 is moved, and 4d is a side guide holder that supports the side guide handle 4c and is attached to the side guide front 4a. Here, the side guide handle 4c is interlocked with a lock mechanism (not shown), and when the side guide handle 4c is pinched, the lock mechanism is released and the side guide unit 4 can be moved.

  When the side guide front unit 4 is moved in the arrow direction (upward) of FIG. 3, the side guide rear unit 5 is interlocked with the arrow direction (downward) of FIG. 3 via the pinion gear 6. Therefore, when setting a sheet in the sheet feeding cassette 2, the user stacks the sheet to be printed on the intermediate plate 3 and then moves the side guide front unit 4 so that the front side guide 4 a comes into contact with the end of the sheet. When moved, the side guide rear unit 5 is also moved in conjunction with the side guide front unit 4 and aligned so that the position of the seat in the left-right direction becomes a predetermined position. When the front side guide 4a comes into contact with the seat and the user releases the side guide handle 4c, a lock mechanism (not shown) is acted again, and the side guide front unit 4 and the side guide rear unit 5 are locked.

  5c is a paper presser, and 5d is a side guide holder attached to the rear side guide 5a. Here, the paper presser 5c plays a role of urging from the other end side so that the stacked sheet end abuts against the side guide front 4a. In the present embodiment, the side guide 5c A total of three are assembled to the rear 5d and side guide 5a, and each is biased to the side guide holder front unit 4 side by an unillustrated elastic member.

  Reference numeral 7 denotes a rear end restricting unit which is a rear end restricting means for restricting the rear end of the sheet. The rear end restricting unit 7 is assembled so as to be slidable in the direction of the arrow in FIG. Yes. 7a is a rear end regulating handle, 7b is a rear end regulating plate that contacts the rear end of the sheet, and the rear end regulating handle 7a is interlocked with a lock mechanism (not shown), and when the rear end regulating handle 7a is pinched. The lock mechanism is released, and the rear end regulating unit 7 can be moved.

  Therefore, when setting a sheet in the sheet feeding cassette 2, the user stacks the sheet to be printed on the intermediate plate 3, and sets the trailing edge regulating unit 7 so that the trailing edge regulating plate 7b contacts the trailing edge of the sheet. Move it so that the trailing edge of the sheet is in place. When the user releases the rear end restricting handle 7a, a lock mechanism (not shown) is acted again and the rear end restricting unit 7 is locked.

  Reference numeral 8 denotes a roller separation unit that frictionally separates a sheet fed by a sheet feeding roller 10 which is a sheet feeding unit constituting a sheet feeding apparatus 1A shown in FIG. A separation roller 8b that frictionally separates the roller 8b is a roller separation holder that holds the separation roller 8a and constitutes a sheet separation unit assembled in the sheet feeding cassette 2.

  Reference numeral 9 denotes a middle plate auxiliary spring which is a second elastic member that pushes the middle plate 3 and the sheet upward in accordance with the sheet stacking amount. In this embodiment, the middle plate auxiliary spring 9 is nonlinear with respect to expansion and contraction. A conical spring that generates pressure is used. Reference numeral 10a denotes a lift arm which is a pressure plate made of sheet metal, and a lift arm slider 10b made of resin is assembled to the tip of the lift arm 10a.

  The lift arm 10a is supported at one end by a lift arm bush 10c and at the other end by a lift arm cam cap 10d, and is assembled so as to be rotatable about the lift arm bush 10c. When the lift arm 10a is rotated upward, the lift arm slider 10b comes into contact with the intermediate plate 3 to push up the intermediate plate 3 and the sheet upward. As a result, the sheet can be pressed against the sheet feeding roller.

  In the present embodiment, as shown in FIG. 4, the roller separation holder 8b is pivotally supported by a roller separation holder support shaft 8c, and both ends of the roller separation holder support shaft 8c are The roller separation attachment 8d is rotatably supported, and both ends thereof are thrust-stopped by a kintee.

  The roller separation attachment 8d is positioned on the paper feed cassette 2, and is fixed to the paper feed cassette 2 with screws at two locations from above. One end of the roller separation holder support shaft 8b is provided with a roller separation holder return spring 8e which is a torsion coil spring. One end of the roller separation holder return spring 8e engages with the roller separation attachment 8d, and the other end. The hook is engaged with the hook 8f.

  Then, the roller separation holder return spring 8e serving as the urging means causes the roller separation holder 8b to move from the first position where the separation roller 8a can be pressed into contact with the paper feed roller 10 to the second position. It is urged to rotate in the direction of moving to the outside, that is, the direction of falling outward as indicated by the arrow A in FIG. The roller separation holder 8b is locked to a rotation stop (not shown) when it rotates a predetermined amount. When replacing the roller separation unit 8, remove the two screws described above, remove the roller separation attachment 8d from the paper feed cassette 2, and attach a new roller separation unit 8 to the paper feed cassette 2 to secure the screws. Like to do.

  Next, the operation of the roller separation holder 8b when the paper feed cassette is mounted will be described with reference to FIGS.

  In FIG. 5, reference numeral 11 denotes a cover that covers a part of the apparatus main body 1, and this cover 11 constitutes a cassette positioning means that determines the position of the paper feed cassette 2. 2a is a fitting hole formed in the sheet feeding cassette 2, 11a is a fitting boss protruding from the cover 11, and when the sheet feeding cassette 2 is inserted into the apparatus main body 1, the fitting boss 11a becomes the fitting hole 2a. With this, the vertical and horizontal positions in the drawing of the paper feed cassette 2 are determined. Reference numeral 11b denotes a tapered slope formed as guide means provided on the cover 11, and reference numeral 1a denotes an opening for attaching / detaching the paper feed cassette 2 to / from the apparatus main body 1.

  By the way, before the sheet feeding cassette 2 is mounted on the apparatus main body 1, specifically, the sheet feeding apparatus main body (not shown), the roller separation holder 8b is biased by the roller separation holder return spring 8e described above. , It has moved to the retracted position that falls in the clockwise direction indicated by the arrow B in FIG. This position is referred to as a second position. Here, in the retracted state, the roller separation holder 8b is attached to the cover 11 which is a positioning member for determining the position of the paper feed cassette 2 when it is set on a cassette rail 12 to be described later for mounting the paper feed cassette 2. On the other hand, it is at a position where it interferes when viewed from the direction in which the paper feed cassette 2 is attached / detached (front side). Thereby, it is not necessary to set a large opening, and the apparatus can be made compact.

  However, even when the roller separation holder 8b is in such a position, when the paper feed cassette 2 is inserted from the direction of the arrow C in the figure, the tip of the roller separation holder 8b comes into contact with the inclined surface 11b of the cover 11, and thereafter The roller separation holder 8b is rotated in the counterclockwise direction indicated by the arrow D in FIG. 7 along the tapered shape of the inclined surface 11b of the cover 11, and is raised in the direction of the first position.

  Further, after this, the roller separation holder 8b is raised to a position over the slope 11b. When the roller separation holder 8b gets over the slope 11b, the roller separation holder 8b is again retracted by the roller separation holder return spring 8e. Held in a state. Thus, even when the roller separation holder 8b is in the second position, the sheet feeding cassette 2 is inserted into the apparatus main body 1 by moving in the direction of the first position by the inclined surface 11b provided on the cover 11. Can do. When moving in the direction of the first position, it is not always necessary to return the separation roller 8a to the first position where the separation roller 8a can be pressed against the paper feed roller 10, and to the extent that it does not contact the edge of the opening of the cover 11. What is necessary is just to make it return to the direction of a 1st position.

  Here, the attachment and detachment of the paper feed cassette 2 is guided by a cassette rail 12 shown in FIG. The cassette rail 12 is slidably held on the cassette rail 12a shown in FIG. 9 fixed to the apparatus main body 1 and the cassette rail 12a, and the paper cassette 2 is attached to the cassette rail 12. It is a telescopic rail composed of the cassette rail inside 12b drawn out by.

  Further, a stopper 12c for preventing the cassette rail 12b from coming off is assembled in the cassette rail 12b, and a slit 12e for moving the stopper 12c is formed on the side surface of the cassette rail outer 12a. The stopper 12c can be slid between the slit rear end 12f and the slit front end 12g, and the cassette rail inner portion 12b can be pulled out of the apparatus body 1 and the cassette rail outer portion 12a by the stroke.

  On the other hand, the roller separation unit 8 is moved to a position in contact with the sheet feeding roller when the sheet feeding cassette 2 is mounted at a position corresponding to the normal mounting position of the sheet feeding cassette 2 on the upper surface of the cassette rail outer 12a. A positioning cam 13 which is a contact means is provided, and the positioning cam 13 guides the roller separation holder 8b to a position where the separation roller 8a is brought into contact with the paper feed roller.

  Reference numeral 14 denotes a positioning cam metal plate for supporting the positioning cam 13, and this positioning cam metal plate 14 is burring crimped to a burring 12d outside the cassette rail 12a. The positioning cam 13 is press-fitted and held in the positioning cam sheet metal 14.

  Here, as shown in FIG. 10, the positioning cam 13 includes a pressing portion 13a and a slope portion 13b. The pressing portion 13a presses the back surface of the roller separation holder 8b, and the slope portion 13b is a roller separation holder. The slope guides 8b to a predetermined position.

  By providing such a positioning cam 13 on the cassette rail outer side 12a, as described above, after overcoming the inclined surface 11b of the cover 11, the state is again retracted by the roller separation holder return spring 8e, that is, the second position. The roller separation holder 8b held in the first position rises along the inclined surface 13b of the positioning cam 13 and comes into contact with the paper feed roller 10 with the subsequent insertion of the paper feed cassette 2 into the apparatus main body. Move to position 1.

  Next, the inserted paper feed cassette 2 is stopped by inserting the fitting boss 11a into the fitting hole 2a of the paper feed cassette 2 as described above. The positions of the paper feed cut 2 and the roller separation holder 8b are determined. That is, when the inserted paper feed cassette 2 reaches a predetermined mounting position, the roller separation holder 8b moves to the first position by the action of the inclined surface portion 13b of the positioning cam 13 against the roller separation holder return spring 8e. In contact with the paper feed roller.

  On the other hand, when the paper feed cassette 2 is pulled out from the apparatus main body 1, the roller separation holder 8b is biased in a direction away from the paper feed roller by the roller separation holder return spring 8e. Along the slope, the sheet is separated from the sheet feeding roller. This position is also referred to as the second position.

  Next, the operation when the roller separation holder 8b is subsequently pulled out will be described with reference to FIG.

  In FIG. 12, reference numeral 17 denotes a front side plate which is a frame member constituting the frame body of the apparatus main body 1, and 15 denotes a return cam which is guide means assembled to the front side plate 17. A slope portion 15a is provided.

  When the paper feed cassette 2 is pulled out in the direction indicated by the arrow F, the roller separation holder 8b is first separated from the paper feed roller along the slope of the slope portion 13b as shown in FIG. Is rotated in the direction indicated by the arrow E, and is locked by the biasing force of the elastic member and the rotation stop when it is rotated by a predetermined amount.

  Here, when moved to such a locking position (second position), the roller separation holder 8 b is in a position where it interferes with the front plate 17. However, even when the roller separation holder 8b is in such a position, if the paper feeding cassette 2 is continuously pulled out, the tip of the roller separation holder 8b comes into contact with the inclined surface portion 15a of the return cam 15, and thereafter the roller separation holder 8b. Is returned along the slope of the slope portion 15a in the direction of contact with the paper feed roller (the direction opposite to the arrow direction). Thus, even when the roller separation holder 8b is in the second position, the sheet feeding cassette 2 is pulled out from the apparatus main body 1 by moving in the direction of the first position by the return cam 15 provided on the front side plate 17. be able to.

  As described above, the roller separation holder 8b is supported by the paper feed cassette 2 so as to be movable between the first position where the roller separation holder 8b can be pressed against the paper feed roller and the second position which is separated from the paper feed roller. The positioning cam 13 provided in the main body 1 moves the roller separation holder 8b to the first position when the paper feed cassette 2 is mounted, and the inclined surface 11b of the cover 11 provided in the main body 1 and the front plate 17 With the return cam 15, the roller separation holder 8 b can be moved from the second position toward the first position in the middle of inserting or pulling out the paper feed cassette 2 with respect to the apparatus main body 1.

  Thereby, even when the roller separation holder 8b is disposed in the sheet feeding cassette 2 and the sheet feeding roller is disposed in the apparatus main body 1, the roller separation holder 8b and the sheet feeding roller may collide when the sheet feeding cassette 2 is attached or detached. Since it is not necessary to provide the apparatus main body 1 with a retracting mechanism for retracting the roller separation holder 8b, the apparatus main body 1 can be made compact.

  Further, the roller separation holder 8b is set to the second position until the paper feeding cassette 2 reaches a predetermined mounting position, and is moved to the first position when the paper feeding cassette 2 reaches the predetermined mounting position. By doing so, uneven wear due to friction between the paper feed roller and the roller separation holder 8b can be eliminated.

  In the description so far, the case where the cover 11 is provided with the opening 1a for attaching and detaching the paper feed cassette 2 to the apparatus main body 1 and the inclined surface 11b formed in a tapered shape has been described. You may make it provide an opening part and a guide means in a part of mold member which comprises the front cover which is the exterior of this, and an apparatus main body.

  Next, a second embodiment of the present invention will be described.

  FIG. 13 is a perspective view of a sheet feeding cassette insertion port of the sheet feeding apparatus according to the present embodiment. In FIG. 13, the same reference numerals as those in FIG. 5 denote the same or corresponding parts.

  In FIG. 13, reference numeral 16 denotes a front cover which is an exterior of the apparatus main body 1. The front cover 16 includes an opening 1a for attaching and detaching the paper feed cassette 2. Further, the opening 1a is a guide member. A slope portion 16a is provided.

  FIG. 14 is a view showing a state when the paper feed cassette 2 is inserted into the apparatus main body 1 from the opening 1 a provided in the front cover 16, and the paper feed cassette 2 is attached to the apparatus main body 1. Previously, the roller separation holder 8b is urged by the roller separation holder return spring 8e described above, and moves in the clockwise direction (G direction) in FIG.

  When the roller separation holder 8b is moved to such a position (second position), the roller separation holder 8b is in a position where it interferes with the front cover 16 in the section viewed from the attachment / detachment direction of the paper feed cassette 2. .

  However, even when the roller separation holder 8b is in such a position, when the paper feed cassette 2 is inserted in the direction of the arrow H in FIG. 14, the tip of the roller separation holder 8 comes into contact with the inclined surface portion 16a of the front cover 16, Thereafter, the roller separating holder 8b is raised by rotating in the counterclockwise direction indicated by an arrow I in FIG. 15 along the tapered shape of the inclined surface portion 16a.

  Thereafter, the roller separation holder 8b is raised to the position over the slope 16b, and when the roller separation holder 8b gets over the slope 16b, the roller separation holder 8b is again retracted by the roller separation holder return spring 8e. Held in a state. In this way, even when the roller separation holder 8b is in the second position, the sheet feeding cassette 2 is inserted into the apparatus main body 1 by moving in the direction of the first position by the inclined portion 16a provided on the front cover 16. can do.

  Next, a third embodiment of the present invention will be described.

  FIG. 16 is a schematic cross-sectional view of the trailing edge regulating unit provided in the sheet feeding apparatus according to the present embodiment. As shown in FIG. 16, does the trailing edge regulating unit 7 contact the trailing edge of the sheet? A rear end regulating plate 7b that is a movable sheet abutting member, a rear end regulating holder 7c that supports the rear end regulating plate 7b, and a rear end regulating that is a pressurizing means that biases the rear end regulating plate 7b forward. A leaf spring 7d is provided.

  Then, the rear end regulating plate 7b is assembled so as to be rotatable about the rotation fulcrum 7e, and is urged by the rear end regulating plate spring 7d in the direction of the arrow shown in FIG. It locks when it hits 7f. Further, when the rear end restricting plate 7b is pushed against the elastic force of the rear end restricting plate spring 7d, the rear end restricting plate 7b is rotated in the direction of the arrow shown in FIG. Is stopped.

  Here, when the sheet cassette 2 is pulled out from the apparatus main body 1, as shown in FIG. 17A, the roller separation holder 8b rotates in the direction of the arrow with the roller separation holder support shaft 8e as a fulcrum, to a predetermined position. The rear end regulating plate 7b is rotated to a position where it abuts against the abutment 7f by the urging force of the rear end regulating plate spring 7f. In this state, the sheet S is replenished to the sheet feeding cassette 2.

  On the other hand, in the process of inserting the sheet feeding cassette 2 loaded with sheets S into the apparatus main body 1, the roller separating holder 8b is moved by the inclined surface 11b of the cover 11 or the inclined surface portion 16a of the front cover 16 as the guide means described above. It rotates in the direction of the arrow shown in FIG. Here, when the roller separation holder 8b rotates as described above, the sheet S is pressed by the roller separation holder 8b and is pushed into the rear end regulating holder side. And the sheet | seat S pushed in in this way rotates the rear-end regulation board 7b in the arrow direction against the elastic force of the rear-end regulation board spring 7d. The paper feed cassette 2 is mounted on the apparatus main body 1 while this operation is repeated by the number of guide means provided on the apparatus main body 1.

  In this way, by moving the roller separation holder 8b at least once in the direction of contacting the paper feed roller 10 during the insertion operation of the paper feed cassette 2, the leading edge of the sheets stacked on the paper feed cassette 2 is It is possible to align with the rear end regulating plate 7b or to align with a predetermined position.

  As a result, even when the user does not set the sheet S in a proper position, the user's inadequate operation can be compensated for by the inevitably operation of inserting the paper feed cassette 2. At the same time, it is possible to cancel an adverse effect on printing accuracy resulting from an insufficient operation of stacking sheets.

  By the way, it is where the sheet feeding cassette 2 is pushed last in the insertion operation of the sheet feeding cassette 2 that feels the most resistance. This is because a fitting portion for positioning the paper feed cassette 2 is coupled and various resistances such as a pressing resistance of the size detection switch are generated. Further, in the configuration in which the roller separation holder 8b is retracted, when the sheet is returned to the first position in contact with the sheet feeding roller, the stacked sheets are closer to the roller separation holder than the predetermined position. A resistance force that pushes the stacked sheets into a predetermined position is generated.

  However, as described above, the roller separation holder 8b is guided to the sheet feeding means side during the insertion operation of the sheet feeding cassette 2, and the sheet S is previously pushed into the trailing edge regulating holder side, thereby feeding the sheet. It is possible to reduce the last pushing resistance that causes the most resistance when the cassette 2 is inserted.

  In the above description, the separation roller unit using the separation roller as the sheet separation unit has been described as an example. However, the present invention is not limited to this, and the separation pad unit using the separation pad is used as the sheet separation unit. It goes without saying that it is also good.

1 is a diagram illustrating a schematic configuration of an image forming apparatus including a sheet feeding device according to a first embodiment of the present invention. FIG. 3 is a perspective view of a sheet feeding cassette that is detachably mounted on the sheet feeding apparatus. The perspective view which shows the state which removed the intermediate plate of the said paper feed cassette. FIG. 3 is a perspective view of a roller separation unit provided in the sheet feeding device. FIG. 3 is a perspective view of a sheet feeding cassette insertion port of the sheet feeding apparatus. FIG. 10 is a first perspective view showing the paper feeding cassette insertion operation. FIG. 10 is a second perspective view showing the sheet feeding cassette insertion operation. FIG. 6 is another perspective view of the sheet feeding cassette insertion port of the sheet feeding apparatus. The perspective view of the cassette rail which guides mounting | wearing of the said paper feed cassette. The perspective view explaining the structure of the said cassette rail. The perspective view which shows the state which the roller separation holder of the said roller separation unit moved to the 2nd position. The perspective view which shows the state of a roller separation holder when pulling out the said paper feed cassette. FIG. 9 is a perspective view of a sheet feeding cassette insertion port of a sheet feeding apparatus according to a second embodiment of the present invention. FIG. 10 is a first perspective view showing the paper feeding cassette insertion operation. FIG. 10 is a second perspective view showing the sheet feeding cassette insertion operation. FIG. 10 is a schematic cross-sectional view of a rear end regulating unit provided in a sheet feeding device according to a third embodiment of the present invention. The figure explaining operation | movement of the roller separation holder of the said sheet feeding apparatus, and a rear-end control unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 1a Opening part 1A Sheet feeding apparatus 2 Sheet cassette 3 Middle plate 7 Rear end regulating unit 7b Rear end regulating plate 7c Rear end regulating holder 7d Rear end regulating plate spring 8 Roller separating unit 8a Separating roller 8b Roller separating holder 8e Roller separation holder return spring 10 Paper feed roller 11 Cover 11b Slope 12 Cassette rail 13 Positioning cam 13a Pressing portion 13b Slope 15 Return cam 15a Slope 16 Front cover 16a Slope 17 Front plate

Claims (9)

A sheet stacking unit that is detachable in a direction crossing a sheet feeding direction with respect to the apparatus main body, a sheet feeding unit that is provided in the apparatus main body and that feeds the sheets stacked on the sheet stacking unit, and the sheet In a sheet feeding apparatus comprising: a sheet separating unit that is attached to a stacking unit and separates the sheets fed in contact with the sheet feeding unit one by one;
The sheet separating means is movably supported between a first position that can be pressed against the sheet feeding means and a second position that is separated from the sheet feeding means, and the sheet is attached to the apparatus body. A contact means for moving the sheet separating means to the first position when the stacking means is mounted is provided, and the sheet separating means is moved while the sheet stacking means is being inserted into or pulled out from the apparatus main body. A sheet feeding apparatus comprising: a guide unit configured to move in a direction from the second position toward the first position. The sheet stacking means includes a rotatable sheet contact member that contacts the rear end of the sheets stacked on the sheet stacking means, and a pressure unit that biases the sheet contact member forward. A sheet trailing edge regulating means for regulating the trailing edge of the sheet to be
When the guide means moves the sheet separating means from the second position toward the first position in the middle of inserting or pulling out the sheet stacking means with respect to the apparatus main body, the sheet separating means is moved. The sheet feeding apparatus according to claim 1, wherein the stacked sheets are pressed backward to align the sheets with the sheet contact member.   The second position is a position that interferes with an opening provided in the apparatus main body for attaching / detaching the sheet stacking unit with respect to the mounting / demounting direction of the sheet stacking unit, and the guide unit is disposed at the opening. 3. The sheet feeding device according to claim 1, wherein the sheet separating unit is moved from the second position toward the first position when the sheet stacking unit is inserted and pulled out by the guide unit. Feeding device.   The sheet feeding apparatus according to claim 1, wherein the sheet separating unit is a separation roller unit using a separation roller or a separation pad unit using a separation pad.   5. The apparatus according to claim 1, wherein the apparatus main body includes a cover member that forms an exterior, and the cover member serves as a guide unit that guides the sheet separating unit in the direction of the first position. The sheet feeding apparatus according to claim 1.   2. The apparatus main body includes a positioning member that determines a position of a sheet stacking unit, and the positioning member functions as a guide unit that guides the sheet separating unit in the direction of the first position. The sheet feeding apparatus according to any one of claims 1 to 4.   The sheet feeding apparatus according to any one of claims 1 to 4, wherein a part of a frame member or a mold member constituting the apparatus main body has a role of the guiding unit.   8. The sheet according to claim 1, further comprising an urging unit that urges the sheet separating unit in a direction in which the sheet separating unit is moved from the first position to the second position. 9. Feeding device. The sheet feeding device according to any one of claims 1 to 8,
An image forming unit that forms an image on a sheet fed from the sheet feeding device;
An image forming apparatus comprising:

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