JP4010997B2 - Sheet supply apparatus for image forming apparatus - Google Patents

Description

  The present invention relates to a sheet supply device such as a cut paper or an OHP sheet, which is applied to an image forming apparatus typified by a copying machine or a printer.

The sheet supply apparatus is used for feeding cut paper in an image forming apparatus typified by a copying machine or a printer. A sheet supply device in the image forming apparatus separates and supplies one sheet at a time from the uppermost layer or the lowermost layer among sheets (cut paper) stacked on a tray. Such a sheet supply device is used for a manual paper feed unit, a cassette type paper feed unit, a document feed unit, and the like of an image forming apparatus. Among these, examples applied to the manual sheet feeder can be seen in Patent Documents 1 to 3.
JP-A-4-153151 JP-A-8-104449 JP 2000-219366 A

  In some cases, a label or the like is attached to a part of the sheet supplied from the sheet supply apparatus. As a result, a thick portion and a thin portion are mixed in the sheet, and the sheet thickness becomes non-uniform. When a plurality of such sheets are stacked on the sheet supply apparatus and supplied to the image forming apparatus, problems such as the sheet being supplied obliquely occur due to unevenness of the sheet. In order to solve such a problem of sheet conveyance failure, it is required to design an apparatus capable of stably supplying sheets one by one in the correct direction by applying pressure in the sheet stacking direction. In this regard, Patent Documents 1 to 3 each take the following measures.

  In the sheet feeding apparatuses described in Patent Documents 1 to 3, the sheet is stacked in the sheet stacking direction from above by a sheet pressing member provided rotatably in the apparatus or from below by a tray that can be rotationally displaced about its fulcrum. The sheet is separated and supplied one by one under pressure. These mechanisms for stable supply of sheets attach weights and springs to the sheet pressing member and tray, and urge the sheet toward the sheet feed roller in the image forming apparatus, which complicates the structure. There is a risk that the cost and assembly man-hour will be increased significantly.

  In Patent Documents 1 and 2, a mechanism for stably supplying sheets is fixed to the apparatus and cannot be attached or detached. As a result, pressure may be applied unnecessarily in the sheet stacking direction, which may cause problems such as wrinkles on the sheet. Further, when the mechanism for stably supplying the sheet is fixed as described above, it cannot be retrofitted as an option to a model in which the mechanism for stably supplying the sheet is not installed in the apparatus from the beginning.

  Further, in Patent Document 3, an apparatus for stably supplying sheets is detachably attached to a tray on which sheets are stacked. However, the apparatus for stably supplying sheets is attached to the tray while the tray is attached to the tray. It cannot be folded and stored in the forming device.

  The present invention has been made in view of the above points, and includes a sheet pressing member that has a simple configuration and can be attached to and detached from existing models without significantly increasing the cost and the number of assembling steps. An object of the present invention is to provide a sheet feeding device of an image forming apparatus capable of separating and feeding even uniform sheets one by one in the correct direction.

  In order to solve the above-described problems, in the present invention, the image forming apparatus can be in a storage and unfolding posture, and is attached to the sheet placement surface of the tray in a direction perpendicular to the sheet supply direction. A sheet feeding device of an image forming apparatus, comprising: a cursor that can move according to a sheet width; and a sheet feeding device that separates and feeds sheets one by one from the uppermost layer of the sheets stacked on the tray. A detachable sheet pressing member that presses the formed sheet from above is provided, and this sheet pressing member has a gantry shape in which both ends of the flat plate in the sheet width direction are bent downward, and the tray is attached with the sheet pressing member. Up to this point, it can be stored in the image forming apparatus.

  Here, the “gantry shape” means a shape like a “gate” provided with legs that support the girder at both ends of a substantially horizontal girder.

  In addition, the sheet pressing member is attached to the tray by engaging the leg portion with the movement groove of the cursor.

  Further, the sheet pressing member is engaged with the moving groove on the outer side in the sheet width direction of the cursor.

  In addition, the sheet pressing member is made of a member having a predetermined elasticity, and can be attached to and detached from the movement groove of the cursor using this elasticity.

  The sheet pressing member includes a sheet pressing film that gradually decreases in height toward the downstream side in the sheet supply direction at the downstream portion in the sheet supply direction, and presses the sheet on the tray downward by the sheet pressing film. It was decided to be a thing.

  In addition, a slit is provided in at least one of the sheet pressing member and the sheet pressing film, and the cursor is engaged with the slit.

  Further, the slit is arranged in accordance with a predetermined sheet width.

  According to the configuration of the present invention, the sheet pressing member can be formed simply by bending a flat plate, and thus the configuration is simple, and the cost and manufacturing man-hours required for manufacturing the sheet pressing member are small. Therefore, it is possible to obtain a sheet pressing member having a simple configuration that does not significantly increase costs and assembly man-hours. In addition, since the tray can be stored in the image forming apparatus with the sheet pressing member attached, it is possible to save time and effort to attach and detach the sheet pressing member each time when storing and unfolding the tray.

  In addition, since the sheet pressing member is attached to the tray by engaging its leg portion with the movement groove of the cursor, a separate mounting member is prepared for mounting the sheet pressing member at a predetermined position. Or processing the tray. Therefore, the cost for attaching the sheet pressing member is extremely small. Further, the attachment can be easily performed because it is only necessary to engage the leg portion of the sheet pressing member with the movement groove of the cursor. Furthermore, the sheet pressing member can be attached to any existing model as long as the model uses a cursor that can move in the sheet width direction.

  Further, since the sheet pressing member is engaged with the cursor movement groove on the outer side in the sheet width direction of the cursor, the movement of the cursor is not hindered. As a result, the cursor can be freely moved inside the sheet pressing member. Therefore, it is possible to freely set the alignment of the cursor in the sheet width direction.

  Further, since the sheet pressing member is made of a member having a predetermined elasticity, the sheet pressing member and its leg are curved in the sheet width direction and are directly engaged with the movement groove of the cursor. By releasing, it becomes possible to attach the sheet pressing member very easily with one touch.

  In addition, since the sheet pressing member includes a sheet pressing film that gradually decreases in height toward the downstream side in the sheet supply direction at the downstream portion in the sheet supply direction, the sheet is moved from the tray into the image forming apparatus. When the sheet is supplied, the sheet is pressed downward by the sheet pressing film, so that the function of stably supplying the sheet in the correct direction is strengthened even if the sheet has a non-uniform thickness by attaching a label or the like. The Moreover, since it is a film form, it is flexible and can be bent greatly. Therefore, even if the number of sheets is increased, it can be sufficiently handled. And unlike metal, a resin film does not rust, so it does not stain the sheet. Furthermore, even if the sheet pressing film is worn due to friction with the sheet, it is possible to reduce the cost of the replacement part at a low cost.

  In addition, since the slit is provided in at least one of the sheet pressing member and the sheet pressing film and the cursor is engaged with the slit, the cursor is covered by the sheet pressing member and the sheet pressing film. However, the presence of the cursor can be confirmed from this slit. Further, the cursor can be positioned by engaging the cursor with the slit.

  In addition, since the slit is arranged in accordance with a predetermined sheet width, even if the tray is not provided with a cursor positioning means such as a latch mechanism, the cursor can be adjusted by aligning the cursor with the slit. It is possible to perform correct positioning.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. Here, it is assumed that the sheet feeding apparatus of the present invention is designed as a manual sheet feeding unit provided on the side surface of the image forming apparatus (printer).

  First, the outline of the structure of a printer, which is an image forming apparatus provided with the sheet supply apparatus of the present invention, will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing a schematic configuration of an image forming apparatus including a manual sheet feeding unit which is a sheet feeding apparatus of the present invention.

  A sheet cassette 3 that is a cassette type paper feeding unit is disposed below the inside of the main body 2 of the printer 1. Inside the sheet cassette 3, sheets S are stacked and accommodated. The sheet S is sent out toward the upper left of the sheet cassette 3 in FIG.

  A sheet conveyance path 4, a registration roller 5, an image forming unit 6, a transfer unit 7, a fixing unit 8, a sheet conveyance path 9, and a sheet discharge unit 10 are arranged on the downstream side of the sheet cassette 3 in the sheet conveyance direction. The sheet discharge unit 10 is provided on the upper surface of the main body 2.

  In FIG. 1, a manual sheet feeder 20 is disposed on the left side surface of the main body 2. As shown in FIG. 1, the manual sheet feeder 20 is deployed leftward and used, and the sheet S is fed toward the lower right. The manual sheet feeder 20 is stored in the main body 2 so as to be folded when not in use. The configuration of the manual sheet feeder 20 will be described in detail later.

  The printer 1 having the above configuration performs an image output operation as follows.

  The sheets S before printing are stacked and stored in the sheet cassette 3 or the manual sheet feeding unit 20, and are separated and sent out one by one. The fed sheet S reaches the registration roller 5 through the sheet conveyance path 4. The registration roller 5 measures the timing of the toner image formed by the image forming unit 6 and sends the sheet S to the transfer unit 7.

  Image data signals such as characters, graphics, and patterns from an external computer (not shown) are transmitted to the printer 1, and an electrostatic latent image based on this image data is created by the image forming unit 6. A toner image is formed from the electrostatic latent image, and the toner image is transferred by the transfer unit 7 to the sheet S sent in synchronization by the registration roller 5.

  The sheet S carrying the unfixed toner image is sent to the fixing unit 8 where the toner image is fixed by the heat roller. The sheet S discharged from the fixing unit 8 is sent upward through the sheet conveyance path 9 and is discharged out of the apparatus from the sheet discharge unit 10 provided on the upper surface of the main body 2.

  Next, a detailed configuration of the manual sheet feeding unit that is the sheet feeding apparatus according to the embodiment of the present invention will be described with reference to FIGS.

  FIG. 2 is a perspective view showing the manual paper feed unit as seen from the upstream side in the sheet supply direction, and FIG. 3 is a perspective view showing the manual paper feed unit as seen from above. FIG. 4 is a perspective view showing the sheet pressing member.

  2 and 3, the manual sheet feeder 20 serving as a sheet supply device includes a tray 21 on which sheets are stacked, and a cursor that can move according to the sheet width in a direction perpendicular to the sheet supply direction (arrow). 22 are provided. The cursor 22 is attached to the sheet placement surface of the tray 21. The cursor 22 can be moved along a movement groove 23 provided on the tray 21 in the sheet width direction. The cursor 22 regulates the movement of the sheets in the width direction so that the stacked sheets stay at a predetermined position. An extension tray 24 that can be expanded according to the size of the stacked sheets is attached to the tray 21. 2 and 3 show the expanded state of the expansion tray 24. FIG. Inside the expansion tray 24, a tray (not shown) that can be expanded by one more stage is provided.

  A sheet pressing member 30 is provided above the cursor 22. The sheet pressing member 30 is provided so as to cover the cursor 22 from the outside of the cursor 22. The sheet pressing member 30 is made of stainless steel having a thickness of 0.5 mm, and has a gantry shape in which both ends of the flat sheet in the sheet width direction are bent downward as shown in FIG. The length of the sheet pressing member 30 in the sheet width direction is the same as the length between both ends of the cursor moving groove 23. The leg portion 30 a of the sheet pressing member 30 is provided with a hook-like engaging claw 31 for attaching the sheet pressing member 30 to the tray 21.

  A sheet pressing film 32 is provided downstream of the sheet pressing member 30 in the sheet supply direction (arrow in FIG. 4). The sheet pressing film 32 is made of polyethylene terephthalate (PET) and is provided so as to gradually lower its height toward the downstream in the sheet feeding direction. The sheets stacked on the tray 21 are pressed downward by the sheet pressing film 32.

  A slit 33 is provided in the joint 30 b between the sheet pressing member 30 and the sheet pressing film 32, and the cursor 22 engages with the slit 33. The slits 33 are arranged in accordance with the sheet width of sheets of A4, B5 size or the like.

  Thus, since the sheet pressing member 30 can be formed by simply bending a flat plate, the sheet pressing member 30 has a simple configuration, and the cost for manufacturing the sheet pressing member 30 and the increase in assembly man-hours can be negligible. Therefore, it is possible to obtain a sheet pressing member 30 having a simple configuration that does not significantly increase costs and assembly man-hours.

  Next, details of attaching the sheet pressing member 30 to the tray 21 will be described with reference to FIGS.

  FIG. 5 is a partially enlarged perspective view showing a cursor and a groove for moving the cursor, and FIG. 6 is a partially enlarged perspective view showing a leg portion of a sheet pressing member attached to the tray. FIG. 7 is a partially enlarged perspective view showing a slit provided in the sheet pressing member.

  The sheet pressing member 30 is attached to the movement groove 23 of the cursor 22 provided on the tray 21 (see FIGS. 5 and 6). When the sheet pressing member 30 is attached to the cursor movement groove 23, the sheet pressing member 30 and its leg 30a are curved inward in the sheet width direction, and the engaging claw 31 provided on the leg 30a is directly used as the cursor movement groove. It can be attached by putting it in 23 and releasing the hand. The leg portion 30a stands on the tray 21. As described above, the sheet pressing member 30 is provided so as to cover the cursor 22 from the outside of the cursor 22 (see FIG. 2). Since the engaging claw 31 is provided on the leg portion 30 a and the leg portion 30 a is positioned at the end of the cursor moving groove 23, the sheet pressing member 30 does not come out upward of the tray 21.

  When the cursor 22 is moved, as shown in FIG. 7, it engages with a slit 33 arranged in accordance with a predetermined sheet width. Note that the cursor 22 shown in FIG. 7 is provided with an engaging protrusion 22a for easily engaging with the slit 33.

  As described above, since the sheet pressing member 30 is attached to the tray 21 with the leg portion 30a engaged with the cursor moving groove 23, the sheet pressing member 30 is separately attached to the predetermined position. There is no need to prepare an attachment member or process the tray. Therefore, the cost for attaching the sheet pressing member 30 is extremely small. Further, the attachment can be easily performed because the leg portion 30a only needs to be engaged with the movement groove 23. Furthermore, the sheet pressing member 30 can be attached to any existing model as long as the model uses the cursor 22 movable in the sheet width direction.

  Further, since the sheet pressing member 30 is engaged with the movement groove 23 on the outer side in the sheet width direction of the cursor 22, the cursor 22 is moved inside the sheet pressing member 30 without hindering the movement of the cursor 22. It is possible to move freely. Therefore, it is possible to freely set the alignment of the cursor 22 in the sheet width direction.

  Since the sheet pressing member 30 is made of a member having a predetermined elasticity such as thin stainless steel, the sheet pressing member 30 and its leg 30a are seated using the elasticity. The sheet pressing member 30 can be bent in the width direction, and the sheet pressing member 30 can be attached to the cursor movement groove 23 with one touch.

  Further, since the slit 33 is provided in the joint portion 30b between the sheet pressing member 30 and the sheet pressing film 32 and the cursor 22 is engaged with the slit 33, the cursor 22 is covered by the sheet pressing member 30 and the sheet pressing film 32. Even if it is broken, the presence of the cursor 22 can be confirmed from the slit 33. In addition, since the slit 33 is arranged in accordance with the sheet width of the A4, B5 size sheet or the like, even if the positioning means for the cursor 22 is not provided in the tray 21, the cursor is placed in the slit 33. By aligning 22, the cursor 22 can be correctly positioned.

  Note that both the sheet pressing member 30 and the sheet pressing film 32 may be made of a transparent synthetic resin. In this case, without providing the slit 33 in the sheet pressing member 30 or the sheet pressing film 32, even if the cursor 22 is completely covered by these members, the position of the cursor 22 can be easily confirmed.

  Next, the sheet supply operation by the manual sheet feeder 20 will be described with reference to FIG. FIG. 8 is a schematic partial cross-sectional view showing the manual sheet feeder.

  When the sheet S is stacked at a predetermined position of the tray 21, the top end of the uppermost layer of the sheet S comes into pressure contact with the sheet feeding roller 25 as a sheet feeding device from below. At this time, the sheet pressing film 32 comes into contact with the upper surface of the uppermost layer of the sheet S and curves. As a result, the sheet S is pressed downward.

  As described above, since the sheet pressing member 30 includes the sheet pressing film 32 that presses the sheet S on the tray 21 downward, a label or the like is attached to the sheet S with a non-uniform thickness. Even if it exists, the effect | action for supplying stably in the right direction is heightened.

  Next, the storing operation of the tray 21 in the printer 1 will be described with reference to FIGS. 9 and 10. FIG. 9 is a schematic partial sectional view showing a state where the tray is unfolded, and FIG. 10 is a schematic partial sectional view showing a state where the tray is stored.

  As shown in FIG. 9, the tray 21 is unfolded at a predetermined angle when used. A cursor 22 and an expansion tray 24 are attached to the tray 21. FIG. 9 shows the extended state of the extension tray 24. A sheet pressing member 30 is attached above the cursor 22.

  When the tray 21 is stored from this state, the expansion tray 24 is moved to the downstream side in the sheet supply direction to be stored in the tray 21, and the main body of the tray 21 is erected vertically to the printer 1 as shown in FIG. And store. In this way, the tray 21 can be stored in the printer 1 with the sheet pressing member 30 attached. Thereby, when the tray 21 is stored and unfolded, it is possible to save the trouble of attaching and detaching the sheet pressing member 30 one by one.

  Although the embodiment of the present invention has been described above, various modifications can be made without departing from the spirit of the present invention.

  The present invention provides a sheet pressing member that is effective when used to print using a sheet having a non-uniform thickness in an image forming apparatus such as a copying machine, and that provides a stable supply of such a sheet. It can be retrofitted to other models.

FIG. 3 is a schematic cross-sectional view illustrating a schematic configuration of an image forming apparatus including a manual sheet feeding unit that is a sheet supply apparatus according to an embodiment of the present invention. These are perspective views of the manual sheet feeder shown in FIG. 1, as viewed from the upstream side in the sheet supply direction. These are perspective views of the manual sheet feeder shown in FIG. FIG. 3 is a perspective view showing a sheet pressing member. FIG. 5 is a partially enlarged perspective view showing a cursor and a groove for moving the cursor. FIG. 4 is a partially enlarged perspective view showing leg portions of a sheet pressing member attached to a tray. FIG. 5 is a partially enlarged perspective view showing a slit provided in the sheet pressing member. FIG. 2 is a schematic partial cross-sectional view of the manual sheet feeder shown in FIG. 1. FIG. 4 is a schematic partial cross-sectional view showing a state where the tray is developed. These are model fragmentary sectional views which show the state which accommodated the tray.

Explanation of symbols

1 Printer 2 Main Body 20 Manual Paper Feed Unit (Sheet Feeder)
21 Tray 22 Cursor 23 Cursor Movement Groove 24 Expansion Tray 30 Sheet Pressing Member 30a Leg 30b Joint 31 Engaging Claw 32 Sheet Pressing Film 33 Slit

Claims (7)

A tray that can be in a storage and unfolding position with respect to the image forming apparatus, a cursor that is attached to a sheet placement surface of the tray, and that is movable in accordance with the sheet width in a direction perpendicular to the sheet supply direction; A sheet feeding device for an image forming apparatus, comprising: a sheet feeding device that separates and feeds one by one from the uppermost layer of the sheets stacked on the tray;
A detachable sheet pressing member that presses the sheets stacked on the tray from above is provided, and the sheet pressing member has a gantry shape in which both ends of the flat sheet in the sheet width direction are bent downward, and the tray is configured to have the sheet pressing member. A sheet supply apparatus for an image forming apparatus, which can be stored in the image forming apparatus with a member attached.   The sheet feeding device of an image forming apparatus according to claim 1, wherein the sheet pressing member is attached to the tray by engaging a leg portion with a movement groove of the cursor.   The sheet feeding device for an image forming apparatus according to claim 2, wherein the sheet pressing member is engaged with the moving groove on the outer side in the sheet width direction of the cursor.   The image according to claim 2, wherein the sheet pressing member is formed of a member having a predetermined elasticity, and can be attached to and detached from the movement groove of the cursor by using the elasticity. Sheet feeding device of the forming apparatus.   The sheet pressing member includes a sheet pressing film that gradually decreases in height toward the downstream side in the sheet supply direction at a downstream portion in the sheet supply direction, and presses the sheet on the tray downward by the sheet pressing film. The sheet supply apparatus for an image forming apparatus according to claim 1, wherein the sheet supply apparatus is an image forming apparatus.   6. The sheet supply device for an image forming apparatus according to claim 5, wherein a slit is provided in at least one of the sheet pressing member and the sheet pressing film, and the cursor is engaged with the slit.   The sheet supply device for an image forming apparatus according to claim 6, wherein the slits are arranged in accordance with a predetermined sheet width.

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