JP2009203052A - Paper feeding device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding device capable of effectively restricting a conveyance failure of a sheet member P, even if the type of the sheet members P is changed, and to provide an image forming device. <P>SOLUTION: When a tray member 12 is released from a first holding position to a second holding position, a driving gear 22 is rotated and a gear group 24 is rotated. When an idle gear 34 constituting the gear group 24 is rotated, a rotary shaft member 36 of the idle gear 32 is rotated, and a tip of a lever member 60 fixed to the rotary shaft member 36 in a base end thereof is rotated. When the tip of the lever 60 is rotated, a pivot shaft member 52 is moved. According to this structure, a retard roller 40 is moved along a feed roller 38. The angle of charge that abuts against the sheet member P on the retard roller 40 can be changed by moving the retard roller 40. As a result of this structure, even if the type of the sheet member P is changed, conveyance failure of the sheet member P can be suppressed effectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet feeding device and an image forming apparatus including the sheet feeding device.

  Japanese Patent Application Laid-Open No. 2005-228561 describes a paper feeding device that includes a manual feed tray that is openable and closable on a side surface of the image forming apparatus, and a paper feed roll that supplies a recording medium loaded on the manual feed tray to the image forming apparatus. ing.

Specifically, the manual feed tray supported so as to be openable / closable is configured to be held at a plurality of open / close angles, and the setting angle of the manual feed tray is changed according to the type of the recording medium so as to reduce the conveyance failure. It has become.
Japanese Patent No. 3828469

  An object of the present invention is to effectively suppress a conveyance failure of a recording medium even if the type of the recording medium placed on the recording medium mounting table provided on the side surface of the main body so as to be opened and closed is changed.

  According to a first aspect of the present invention, there is provided a sheet feeding device that can be opened and closed in a main body, and in a released state, a recording medium mounting table on which a recording medium supplied to the main body can be stacked, and a plurality of opening and closing angles. A holding unit that holds the recording medium mounting table; a paper feed roll that feeds the recording medium against the recording medium placed on the recording medium mounting table held by the holding unit; and A separation roll that is disposed at an opposing position and prevents conveyance of the recording medium by applying a conveyance resistance to the recording medium conveyed by the paper feed roll, and receives an opening / closing force of the recording medium mounting table. Separating roll moving means for moving the separating roll in the circumferential direction of the paper feed roll and changing a plunging angle when the recording medium placed on the recording medium mounting table enters the separating roll. And wherein the Rukoto.

  The sheet feeding device according to a second aspect of the present invention is the paper feeding device according to the first aspect, wherein the separation roll moving means is configured to freely rotate the driving gear provided on the shaft member of the recording medium mounting table and the separation roll. A supporting member to be supported; a moving member that is coupled to the supporting member, moves the supporting member, and moves the separation roll in a circumferential direction of the paper feed roll; and a rotational force of the drive gear to the moving member And a rotational force transmitting member for transmitting to the vehicle.

  According to a third aspect of the present invention, in the paper feeding device according to the second aspect, the support member is provided with a pivot shaft member that swingably supports the separation roll, and the rotational force transmitting member is A gear group to which the rotational force of the drive gear is transmitted; and the moving member includes a rotary shaft member to which the rotational force is transmitted from the gear group, one end fixed to the rotary shaft member, and the other end to the pivot And a lever member rotatably connected to the shaft member.

  According to a fourth aspect of the present invention, in the paper feeding device according to the third aspect, the gear ratio between the drive gear and the gear group is such that the rotational force of the drive gear is amplified and transmitted to the rotary shaft member. It is characterized by being decided.

  According to a fifth aspect of the present invention, there is provided an image forming apparatus according to any one of the first to fourth aspects, and a conveying roll for conveying a recording medium supplied by the paper feeding apparatus to an image forming unit. And.

  According to the paper feeding device of the first aspect of the present invention, the rush angle is compared with the case where the rush angle is not changed when the separation roll is moved in the circumferential direction of the paper feed roll and the recording medium enters the separation roll. Therefore, even if the type of the recording medium changes, it is possible to effectively suppress the recording medium conveyance failure.

  According to the paper feeding device of the second aspect of the present invention, it is possible to move the separation roll using the opening / closing force of the recording medium mounting table by a simple method as compared with the case where the drive gear is not provided.

  According to the sheet feeding device of the third aspect of the present invention, the pivot shaft member is provided and the support member is swung as compared with the case where the pivot shaft member is not provided on the support member supporting the separation roll. The nip pressure between the paper feed roll and the separation roll can be changed, and even if the type of the recording medium is changed, the conveyance failure of the recording medium can be effectively suppressed.

  According to the paper feeding device of the fourth aspect of the present invention, the rotation moment due to the weight of the recording medium mounting table is amplified and transmitted to the pivot shaft member as compared with the case where this configuration is not provided. The shaft portion and the separation roll can be held in a stable state.

  According to the image forming apparatus of the fifth aspect of the present invention, compared with the case where the sheet feeding device described in any one of the first to fourth aspects is not provided, the recording medium in which the conveyance failure is suppressed is imaged. The image can be conveyed to the forming unit and an image can be formed at a predetermined position on the recording medium.

An embodiment of an image forming apparatus employing an example of a paper feeding device according to the present invention will be described with reference to FIGS.
(overall structure)
As shown in FIG. 11, the image forming apparatus 100 includes a photosensitive member 88 on which an electrostatic latent image is formed by irradiating a laser beam after being uniformly charged, and a surface of the photosensitive member 88. A charging device 90 for uniformly charging, an exposure device 92 for forming an electrostatic latent image by irradiating the photosensitive member 88 with laser light based on image data, and selectively transferring toner to the electrostatic latent image. A developing device 94 that visualizes the toner image, a transfer roll 62 that transfers the toner image on the surface of the photosensitive member 88 to a sheet member P serving as a recording medium supplied along the conveyance path 96, and a toner image on the sheet member P. Are fixed to the sheet member P by heating and pressing, and a cleaning device 66 for cleaning the toner remaining on the photosensitive member 88 after the toner image is transferred.

  The image forming apparatus 100 is covered with a main body side cover 100B and a top plate 100A.

  Here, the photosensitive member 88, the charging device 90, the developing device 94, and the cleaning device 66 constitute a single developing unit 76, and the top plate 100A of the image forming apparatus 100 is rotated in the direction of arrow A with the shaft 100C as a fulcrum. Thus, the inside is opened, and the developing unit 76 can be easily attached and detached from the main body frame (not shown).

  Further, a sheet feeding device 74 that manually feeds the sheet member P to the image forming unit 70 that forms an image on the sheet member P is provided on the side surface of the image forming device 100. A paper feed cassette 80 on which a plurality of sheet members P are stacked is provided on the lower side of the inside.

  Further, a pick-up roll 82 is provided to hit the uppermost sheet member P stacked on the paper feed cassette 80 and take out the sheet member P. The sheet members P stacked on the paper feed cassette 80 are sequentially taken out by the pick-up roll 82. It is supposed to be. Further, the sheet member P taken out by the pickup roll 82 is conveyed one by one by a feed roll 84 and a retard roll 86 which are provided downstream of the pickup roll 82 and are driven to rotate. Details of the paper feeding device 74 will be described later.

  The photosensitive member 88 has a photosensitive layer on the back surface, and the potential of the exposed portion is attenuated by exposure after being uniformly charged.

  Further, the charging device 90 is a roll-shaped member that comes into contact with and contacts the photoconductor 88, and when a voltage is applied between them, a discharge is generated in a minute gap between the charging device 90 and the photoconductor 88, thereby The surface of the body 88 is charged almost in the same manner. As the charging device 90, in addition to the above, a device that applies a high voltage to the electrode wire and charges the photosensitive member 88 by corona discharge can be used.

  The exposure device 92 scans the peripheral surface of the photosensitive member 88 with a blinking laser beam, and forms an electrostatic latent image based on the image data on the peripheral surface of the photosensitive member 88. As the writing device, a light emitting element such as an LED may be arranged and blinked based on the image data.

  Further, the developing device 94 has a cylindrical developing roll 94A disposed so as to face the photosensitive member 88 in the vicinity thereof, and a developing bias voltage is applied between the developing roll 94A and the photosensitive member 88. . As a result, a developing bias electric field is formed between the developing roller 94A and the photosensitive member 88, and the charged toner is transferred to the exposed portion on the photosensitive member 88 to form a toner image.

  The transfer roll 62 is a roll-shaped member provided so as to face the photoconductor 88, and forms a transfer electric field between the transfer roll 62 and the sheet member P passing through the image forming unit 70. The toner image is transferred to the top.

  In the image forming apparatus 100 described above, first, the charging device 90 to which a voltage is applied uniformly charges the surface of the photosensitive member 88 at a predetermined potential. Subsequently, the exposure device 92 forms an electrostatic latent image on the charged photoreceptor 88 based on image data read by a scanner (not shown).

  That is, an electrostatic latent image corresponding to the image data is formed on the photoconductor 88 by turning on and off the laser based on image data supplied from a control device (not shown). Further, the electrostatic latent image is visualized as a toner image by toner supplied from a developing roll 94A provided in the developing device 94.

Therefore, the sheet member P taken out from the paper feed cassette 80 by the pickup roll 82 is handed to the transport roll 68 one by one by the feed roll 84 and the retard roll 86 and is sent out to the transport path 96. The sheet member P sent to the conveyance path 96 passes through the image forming unit 70 which is a sandwiching portion between the photosensitive member 88 and the transfer roll 62, and the toner image is transferred to the sheet member P. The transferred toner image is fixed on the sheet member P by passing between a heating roll 64H and a pressure roll 64N provided in the fixing device 64, and is discharged onto the top surface of the top plate 100A by the discharge roll 72. .
(Main part configuration)
Next, the paper feeding device 74 will be described.

  The sheet feeding device 74 is provided with a curved plate-like cover member 10 which is provided on the side surface of the image forming apparatus 100 so as to be openable and closable and is exposed to the outside at a storage position (position shown in FIG. 11) stored on the side surface. Yes. Furthermore, a plate-like tray member 12 on which the sheet member P supplied manually is placed is provided inside the cover member 10.

  Specifically, as shown in FIG. 1, columnar rod portions 12 </ b> A protrude from both ends of the tray member 12, and long hole-shaped guides that hold the rod portions 12 </ b> A so as to be movable. The part 10 </ b> A is provided on the cover member 10.

  When the cover member 10 is opened and closed in the direction of arrow B shown in FIG. 11, the cover member 10 rotates about the rotation shaft 14 and the tray member 12 opens and closes about the rotation shaft 16. Further, as shown in FIG. 1, the rod portion 12A provided on the tray member 12 moves in the guide portion 10A, and as shown in FIG. 10, the cover member 10 and the tray member 12 are opened.

  Further, as shown in FIG. 1, a holding member 20 as a holding unit that holds the tray member 12 is provided at one end of the rotation shaft 16 of the tray member 12 at a position where the sheet member P can be supplied. . The holding member 20 is configured to hold the tray member 12 at a first holding position indicated by a two-dotted line in FIG. 10 and a second holding position indicated by a solid line. As the holding member 20, for example, a latch mechanism by hooking or the like can be employed.

  Further, as shown in FIG. 1, a driving gear 22 is fixed to the other end of the rotating shaft 16 of the tray member 12, and when the tray member 12 is opened, the driving gear 22 rotates in the direction of arrow C. It is supposed to be.

  A gear group 24 that receives the rotational force of the drive gear 22 is provided below the drive gear 22. The gear group 24 includes an idle gear 28 that meshes with the drive gear 22 and an idle gear that meshes with the idle gear 28. 30, an idle gear 32 that meshes with the idle gear 30, and an idle gear 34 that meshes with the idle gear 32 are provided.

  The gear ratio between the drive gear 22 and the idle gears 28, 30, 32, and 34 is determined so as to amplify the rotational force of the drive gear 22 and transmit it to the rotary shaft member 36 of the idle gear 34.

  FIG. 3 shows the tray member 12 held at the first holding position. When the cover member 10 and the tray member 12 are rotated in the arrow D direction from the first holding position, the tray member 12 can be moved to the second holding position shown in FIG.

  Here, when the tray member 12 is rotated from the first holding position to the second holding position, the drive gear 22 rotates in the direction of arrow C as shown in FIG. Thus, the idle gear 30 is rotated in the direction of arrow F, whereby the idle gear 32 is rotated in the direction of arrow G, whereby the idle gear 34 is rotated in the direction of arrow H.

  On the other hand, as shown in FIG. 1, the vicinity of the front end of the sheet member P stacked on the tray member 12 is placed, and a bottom plate 48 that can move up and down is provided in the sheet material conveyance direction of the tray member 12. Yes. When the bottom plate 48 moves up and down, the leading end of the sheet member P placed on the tray member 12 is pressed against a feed roll 38 described later. Further, side guides 50 that determine the position of the sheet member P in the width direction are provided on both ends of the tray member 12 in the sheet material width direction so as to be movable in the sheet material conveyance direction.

  Further, a half-moon-shaped feed roll 38 is provided at a position facing the bottom plate 48 to feed the sheet member P placed on the tray member 12 to the image forming unit 70 (see FIG. 11). Further, a retard roll 40 is provided with the sheet member P sandwiched between the feed roll 38.

  As shown in FIG. 8, the rotation shaft member 58, which is the rotation center of the retard roll 40, is pivotally supported by the support member 42 that is open at the top, and further below the support member 42 is the support member 42. A coil spring 44 (see FIG. 5) is provided to urge the supported retard roll 40 toward the feed roll 38 (see FIG. 1). In FIG. 8, the feed roll 38 is omitted in order to clarify the configuration of the retard roll 40.

  Further, a torque limiter 46 is provided on the rotating shaft member 58 of the retard roll 40 so that a predetermined (relatively large) torque is applied to the retard roll 40 in advance. A predetermined nip pressure is maintained at a nip portion between the retard roll 40 and the feed roll 38 by a coil spring 44 (see FIG. 5) provided below the support member 42. The coil spring 44 is fixed to the main body, and is in the same position even if the support member 42 moves. For this reason, when the retard roll 40 receives the rotational force of the feed roll 38 via one sheet material, it rotates without moving relative to the sheet member P, but the two to three sheet members P are heavy. When fed, since the frictional resistance between the two or three sheet members P is small, only the uppermost sheet member P is conveyed to the image forming unit 70 by the feed roll 38, and the lower sheet member P is retarded. The feed is blocked by the rotational resistance of the roll 40.

  The support member 42 is provided with a columnar pivot shaft member 52 that supports the retard roll 40 so as to be swingable. The pivot shaft member 52 is movably fitted in a long hole 56 formed in a wall member 54 provided in the main body. Further, the distal end portion of the pivot shaft member 52 passes through the long hole 56 and is rotatably supported by the distal end portion of the plate-like lever member 60.

As shown in FIGS. 7 and 9, the base end portion of the lever member 60 is fixed to the rotary shaft member 36 of the idle gear 34 described above.
(Function)
With the above configuration, as shown in FIG. 11, the tray member 12 disposed in the storage position is opened, and the tray member 12 is moved to the first holding position shown in FIGS.

  As shown in FIG. 5, in the state where the tray member 12 (see FIG. 1) is disposed at the first holding position, the pivot shaft member 52 that supports the retard roll 40 so as to be swingable is one end of the long hole 56. Located in the department.

  When the tray member 12 is opened from the first holding position (see FIGS. 1 and 3) to the second holding position, the drive gear 22 fixed to the rotating shaft 16 of the tray member 12 as shown in FIG. Rotates in the direction of arrow C, thereby rotating the idle gear 28 in the direction of arrow E, thereby rotating the idle gear 30 in the direction of arrow F, thereby rotating the idle gear 32 in the direction of arrow G. The idle gear 34 rotates in the arrow H direction. Note that an engagement member (not shown) is provided between the drive gear 22 and the rotary shaft 16, and the drive is performed when the tray member 12 rotates between the first holding position and the second holding position. The gear 22 and the rotating shaft 16 are engaged and rotate at the same time.

  As shown in FIG. 7, when the idle gear 32 rotates in the arrow H direction, the rotating shaft member 36 of the idle gear 32 also rotates in the arrow H direction. When the rotary shaft member 36 rotates in the arrow H direction, the distal end portion of the lever member 60 whose base end portion is fixed to the rotary shaft member 36 also rotates.

  When the distal end portion of the lever member 60 rotates, the pivot shaft member 52 attached to the distal end portion of the lever member 60 moves. Specifically, when the tip of the lever 60 rotates, the pivot shaft member 52 moves from the position shown in FIG. 5 located at one end of the long hole 56 to the position shown in FIG. 6 located at the other end of the long hole 56. To do.

  As the pivot shaft member 52 moves, the retard roll 40 also moves from the position of the two-dot chain line shown in FIG. 6 to the position of the solid line. Here, the support member 42 that supports the retard roll 40 is urged toward the feed roll 38 by the coil spring 44. Therefore, the retard roll 40 moves along the outer surface of the feed roll 38. become.

  FIG. 5 showing the position of the retard roll 40 when the tray member 12 is held at the first holding position, and FIG. 6 showing the position of the retard roll 40 when the tray member 12 is held at the second holding position. 5 and FIG. 6, the entry angle between the sheet member P stacked on the tray member 12 and the retard roll 40 is changed. The entry angle is an angle formed by the tangent line of the retard roll 40 and the sheet member P at the entry point where the sheet member P placed on the tray member 12 hits the retard roll 40.

  As shown in FIG. 5, at the arrangement position of the retard roll 40 corresponding to the first holding position, the rush angle becomes M, and as shown in FIG. 6, the retard roll 40 corresponding to the second holding position. In the arrangement position, the entry angle is N. As can be seen from FIGS. 5 and 6, the rush angle N at the position where the retard roll 40 corresponding to the second holding position is smaller than the rush angle M.

  When the leading end of the sheet member P is conveyed to the nip position between the feed roll 38 and the retard roll 40, the smaller the entry angle, the smaller the amount of deformation (degree of curvature) of the leading end of the sheet member P is.

  Then, when the tray member 12 is held at the second holding position where the entry angle is small, it is preferable to supply thick paper or the like having high rigidity. Since the amount of deformation of the tip portion is small, conveyance failure is suppressed. Further, curling of the front end portion of the sheet member P is also suppressed. Further, the sheet sliding noise is reduced, and the conveyance resistance (load) is also reduced.

  Further, the distance from the entry point where the sheet member P placed on the tray member 12 hits the retard roll 40 to the nip position of the feed roll 38 and the retard roll 40 is compared in FIG. 5 and FIG.

  As shown in FIG. 5, in the arrangement position of the retard roll 40 corresponding to the first holding position, the distance from the entry point to the nip position is Q, and as shown in FIG. At the corresponding arrangement position of the retard roll 40, the distance from the entry point to the nip position is R. As can be seen from FIGS. 5 and 6, the distance Q from the entry point to the nip position at the arrangement position of the retard roll 40 corresponding to the first holding position is longer than the distance R at the second holding position.

  The longer the distance from the entry point to the nip position, the longer the distance at which the sheet member P is conveyed from the entry point to the nip position, and the stacked sheet members P can be separated between them. Is prevented.

  Then, when the tray member 12 is held at the first holding position where the distance from the entry point to the nip position is long, it is preferable to supply plain paper that is easy to double feed.

  Further, by holding the tray member 12 at the first holding position, a space when the tray member 12 is opened is reduced.

  During the conveyance of the sheet, the load of the torque limiter 46 attached to the retard roll 40 is pressurized toward the feed roll around the pivot shaft, so that the nip pressure tends to increase. This nip pressure has the effect of changing by changing the pivot axis position with respect to the paper conveyance direction. Therefore, when supplying thick paper that requires conveyance force, a high nip pressure is used, and plain paper that does not require much conveyance force. Can be set to a lower nip pressure.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. For example, in the above embodiment, the rotational force of the tray member 12 is transmitted to the retard roll 40 by the gear group 24, but the rotational force of the tray member may be transmitted using a link, a pulley, a roller, and the like.

  Moreover, in the said embodiment, although the tray member 12 was hold | maintained in two places, a 1st holding position and a 2nd holding position, it is not limited to two places, Three or more places may be sufficient.

FIG. 4 is a perspective view illustrating a sheet feeding device according to an embodiment of the present invention and illustrating a state in which a tray member is rotated and moved to a first holding position. FIG. 5 is a perspective view illustrating a sheet feeding device according to an embodiment of the present invention and illustrating a state in which a tray member is rotated and moved to a second holding position. FIG. 6 is a side view illustrating a state in which the tray member is rotated and moved to the first holding position, showing the sheet feeding device according to the embodiment of the present invention. FIG. 5 is a side view illustrating a state where the tray member is rotated and moved to a second holding position, showing the sheet feeding device according to the embodiment of the present invention. FIG. 5 is an enlarged side view showing a retard roll, a feed roll, and the like employed in the paper feeding device according to the embodiment of the present invention when the tray member is disposed at a first holding position. FIG. 5 is an enlarged side view illustrating a retard roll, a feed roll, and the like employed in the paper feeding device according to the embodiment of the present invention when the tray member is disposed at a second holding position. FIG. 4 is an enlarged perspective view showing a retard roll, a feed roll, and the like employed in the paper feeding device according to the embodiment of the present invention, and a tray member disposed at a first holding position. FIG. 4 is an enlarged perspective view showing a retard roll or the like employed in the paper feeding device according to the embodiment of the present invention when the tray member is disposed at a first holding position. FIG. 5 is an enlarged perspective view illustrating a lever member and the like employed in the paper feeding device according to the embodiment of the present invention when the tray member is disposed at a first holding position. 1 is a schematic configuration diagram of an image forming apparatus in which a paper feeding device according to an embodiment of the present invention is employed. 1 is a schematic configuration diagram of an image forming apparatus in which a paper feeding device according to an embodiment of the present invention is employed.

Explanation of symbols

12 Tray member (recording medium mounting table)
16 Rotating shaft (shaft member)
20 Holding member (holding means)
22 Drive gear 24 Gear group 36 Rotating shaft member 38 Feed roll (paper feed roll)
40 retard roll (separation roll)
42 Support member 52 Pivot shaft member 60 Lever member (moving member)
70 Image forming unit 74 Paper feeding device 100 Image forming device (main body)

Claims (5)

A recording medium mounting table provided on the main body so as to be openable and closable, and capable of stacking a recording medium supplied to the main body in an open state;
Holding means for holding the recording medium mounting table at a plurality of opening and closing angles;
A paper feed roll that feeds the recording medium against the recording medium placed on the recording medium mounting table held by the holding means;
A separation roll that is disposed at a position facing the paper feed roll and prevents double feeding of the recording medium by applying a transport resistance to the recording medium transported by the paper feed roll;
In response to the opening / closing force of the recording medium mounting table, the separation roll is moved in the circumferential direction of the paper feeding roll, and a rush angle when the recording medium placed on the recording medium mounting table enters the separation roll is determined. A separating roll moving means for changing,
A sheet feeding device comprising: The separation roll moving means includes
A drive gear provided on a shaft member of the recording medium mounting table;
A support member for rotatably supporting the separation roll;
A moving member connected to the supporting member, moving the supporting member, and moving the separation roll in a circumferential direction of the paper feed roll;
A rotational force transmitting member that transmits the rotational force of the drive gear to the moving member;
The sheet feeding device according to claim 1, further comprising: The support member is provided with a pivot shaft member that supports the separation roll in a swingable manner.
The rotational force transmitting member is
A gear group to which the rotational force of the drive gear is transmitted;
The moving member includes a rotating shaft member to which a rotational force is transmitted from the gear group, a lever member having one end fixed to the rotating shaft member and the other end rotatably connected to the pivot shaft member;
The sheet feeding device according to claim 2, further comprising:   4. The sheet feeding device according to claim 3, wherein a gear ratio between the drive gear and the gear group is determined so as to amplify a rotational force of the drive gear and transmit it to the rotation shaft member. A paper feeding device according to any one of claims 1 to 4,
A transport roll for transporting the recording medium supplied by the paper feeder to the image forming unit;
An image forming apparatus comprising:

Images