JP2018154491A - Sheet supply mechanism, sheet supply device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely and smoothly supply stacked sheets according to a type of a sheet size etc., without damaging a surface.SOLUTION: A paper feeder 5 includes a main feeding roller 39 and an auxiliary feeding roller 61 on an upstream side of the main feeding roller 39 in a sheet feeding direction, in order to feed the sheet on a stacking tray 36 in a sheet conveying direction. A controller 35 performs controls so as to recognize whether the sheet on the stacking tray has a normal sheet size or a long sheet size, on the basis of a detection result of a first upper surface detector 39 for detecting an uppermost surface of the sheet on the stacking tray 36, and a second upper surface detector 66 for detecting an uppermost surface of a rear end portion of the long sheet in the paper feeding direction, and drive only a main feeding roller in a case of a normal sheet size, and make the main feeding roller and the auxiliary feeding roller cooperate in a case of a long sheet size.SELECTED DRAWING: Figure 2

Description

  The present invention relates to, for example, an image forming apparatus or a sheet supply mechanism for supplying a sheet to an image forming unit thereof, a sheet supply apparatus using the same, and an image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine includes a sheet supply unit and an externally attached sheet supply device in order to supply a sheet as recording paper to the image forming unit. In general, a sheet supply unit and a sheet supply apparatus include a feeding roller for feeding a sheet stacked on a predetermined cassette or tray to the image forming unit side, and a separation mechanism for separating and feeding the fed sheet into one sheet. A sheet supply mechanism comprising: In many cases, the feeding roller is arranged near the downstream end in the feeding direction of the sheet on the cassette or the tray and near the center in the sheet width direction, and rotates while contacting the top surface of the sheet with a substantially constant pressing force. Send it out.

  Various types of sheets are used for the recording paper of the image forming apparatus in terms of size, thickness (weight), material, properties, usage, and the like. For example, in addition to the JIS standard A4 size, A3 size, B5 size, B4 size, US standard letter size and legal size, A0 size, A1 size, A2 size etc. There are large and long sheets that are out of stock and non-standard. Other than sheet sizes, in addition to plain paper often used in copiers, there are glossy paper such as coated paper, recycled paper, used paper, tracing paper, and plastic sheets such as transparent film for OHP. However, processed products such as those having different thickness, weight, hardness, stiffness, and surface smoothness, and envelopes are also used.

  In general, the feeding roller has a sheet conveying force that is set mainly on types of frequently used sheets. Therefore, depending on the type of the sheet, the sheet conveying force of the feeding roller is not sufficient, and there is a possibility that a feeding failure such as sheet non-feed or paper jam may occur.

  In order to solve this problem, various sheet supply mechanisms have been proposed. For example, a sheet feeding device is known that can amplify the pressing force of a sheet feeding rotating body (roller) in contact with a sheet according to the sheet size (see, for example, Patent Document 1). In addition, a paper feed mechanism is known in which the pressing force of a pickup roller can be increased according to the type of recording paper to be loaded (see, for example, Patent Document 2).

JP-A-8-119472 JP 2007-254089 A

  However, when the uppermost sheet is fed out with a strong pressing force as in the above-described conventional sheet feeding device or sheet feeding mechanism, damage such as wrinkles and dirt due to roller rubbing remains on the surface of the fed sheet as roller marks. There is a fear.

  The present invention solves such a problem, and even when the sheet type, for example, the sheet size is different from that of the sheet normally used, the stacked sheets are always reliably left without leaving a roller mark on the surface. It is another object of the present invention to provide a sheet supply mechanism and a sheet supply apparatus that can supply smoothly.

The sheet supply mechanism of the present invention includes a sheet stacking tray for stacking sheets,
A main feeding roller for feeding out the sheets on the sheet stacking tray in the sheet feeding direction;
An auxiliary feeding roller disposed upstream of the main feeding roller in the sheet feeding direction in order to feed the sheets on the sheet stacking tray in the sheet feeding direction;
Driving means for driving the main feeding roller and the auxiliary feeding roller,
The driving means corresponds to the type of sheets on the sheet stacking tray, and drives the main feeding roller to drive the sheets on the sheet stacking tray without driving the auxiliary feeding roller, and the main feeding operation. A second feeding operation for feeding the sheets on the sheet stacking tray by driving the roller and the auxiliary feeding roller is selectively performed.

  In an embodiment, the driving means drives the auxiliary feeding roller so as to cooperate with the main feeding roller in the second feeding operation.

  In another embodiment, the type of sheet is the length of the sheet, and when the length of the sheet is longer than a predetermined length, the driving unit performs the second feeding operation.

  In another embodiment, there is further provided a long sheet detecting means for detecting that the length of the sheet on the sheet stacking tray is longer than a predetermined length.

  In still another embodiment, the long sheet detecting means detects the position of the auxiliary feeding roller that contacts the uppermost surface of the sheet on the sheet stacking tray.

  In another embodiment, there is further provided an input means for inputting the type of sheet on the sheet stacking tray.

  In another embodiment, the auxiliary feeding roller is disposed at a position that does not overlap the main feeding roller in the sheet width direction perpendicular to the sheet feeding direction along the sheet feeding direction.

  In some embodiments, an extension tray is provided for stacking and supporting a portion protruding beyond the predetermined length of the sheet on the sheet stacking tray to the upstream side in the sheet supply direction.

  In another embodiment, the extension tray is detachably provided on the sheet stacking tray.

  In a certain embodiment, the control means which controls a drive means so that a drive means may perform 1st, 2nd delivery operation | movement is provided.

  In another embodiment, the driving means has first driving means for driving the main feeding roller and second driving means for driving the auxiliary feeding roller.

  According to another aspect of the present invention, there is provided a sheet supply apparatus including the above-described sheet supply mechanism of the present invention in order to supply the sheet on the sheet stacking tray in the sheet supply direction.

  According to still another aspect of the present invention, there is provided an image forming apparatus including the above-described sheet supply mechanism or sheet supply apparatus of the present invention in order to supply a sheet on a sheet stacking tray to an image forming unit.

  The sheet supply mechanism of the present invention includes a main supply roller and an auxiliary supply roller disposed upstream of the sheet supply direction in order to supply the sheet on the sheet stacking tray in the sheet supply direction, and the driving unit includes The first feeding operation for driving the main feeding roller to feed the sheet on the sheet stacking tray without driving the auxiliary feeding roller, the main feeding roller and the auxiliary corresponding to the type of sheet on the sheet stacking tray By selectively executing the second feeding operation of feeding the sheets on the sheet stacking tray by driving the feeding roller, the sheets on the stacking tray are always reliably and smoothly removed from the stacking tray according to the type of the sheet. It can be fed out.

1 is an overall configuration diagram of an image forming system including a sheet feeding device according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram illustrating an internal configuration of the sheet feeding device illustrated in FIG. 1. FIG. 2 is an explanatory view of the inside of the paper feeding device of FIG. 1 viewed from above. 2A and 2B are explanatory views of a rear end regulating member of the sheet feeding device of FIG. 1, in which FIG. 1A shows a state of a rear end regulating member when storing a normal size sheet, and FIG. Show. FIG. 2 is an explanatory diagram illustrating an internal state of the sheet feeding device illustrated in FIG. 1 when a normal size sheet is fed. FIG. 2 is an explanatory diagram illustrating an internal state of the sheet feeding device illustrated in FIG. 1 when a long sheet is fed. 3 is a flowchart illustrating a procedure for stacking sheets on the sheet feeding device illustrated in FIG. 1. 6 is a flowchart illustrating an operation until a standby state is entered after sheets are stacked on a stacking tray. 6 is a flowchart illustrating details of a paper feed process. 6 is a flowchart illustrating details of a sheet feeding operation in a normal sheet mode. 6 is a flowchart illustrating details of a sheet feeding operation in a long sheet mode. It is explanatory drawing which shows the internal structure of the paper feeder which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the stacking preparation position of the stacking tray at the time of a small size sheet. It is explanatory drawing which shows the stacking preparation position of the stacking tray at the time of a large sized sheet. 13 is a flowchart illustrating a procedure for stacking sheets on the sheet feeding device illustrated in FIG. 12.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present specification, the “conveying direction” and “sheet feeding direction” of the sheet mean the direction in which the sheet is conveyed from the sheet feeding device 5 to the image forming apparatus 2, and the “width direction” of the sheet. The term “direction” means a direction that intersects the sheet conveyance direction and the sheet feeding direction in the sheet plane (in this embodiment, a direction that is orthogonal to the sheet conveyance direction in the sheet plane).

  First, the overall configuration of the image forming system 1 will be described with reference to FIG. The image forming system 1 includes an image forming apparatus 2, a document reading device 3, a document feeding device 4, a sheet feeding device 5, and a sheet stacking device 6. The image forming apparatus 2 includes a paper feed cassette 7 (in the illustrated embodiment, two paper feed cassettes 7a and 7b) that can store about 100 sheets. The image forming apparatus 2 forms an image on a sheet supplied from any one of the sheet feeding cassettes 7 a and 7 b and the sheet feeding apparatus 5 based on the image data read from the document image by the document reading device 3. Then, the image-formed sheets are collected and stored in the sheet stacking device 6. A document sheet can be fed to the document reading device 3 by the document feeding device 4.

  Sheets handled as recording paper in the image forming system 1 include various types of sheets in terms of sheet size, thickness or weight, material, properties, usage, and the like. In addition to A4 size, A3 size, B5 size, B4 size, US standard letter size, legal size, etc. of general JIS standards, standard products such as A0 size, A1 size, A2 size, etc. Non-standard large and long sheets are included. Examples of the material include glossy paper such as plain paper and coated paper, which are often used for copy paper, recycled paper, used paper, and plastic sheets such as OHP transparent films. Further, it includes sheets having different thicknesses, that is, weight, hardness, stiffness, and surface smoothness, and processed products such as envelopes.

  The image forming apparatus 2 is, for example, a copying machine, a printer, a facsimile, or the like, and is installed on the floor surface. The image forming apparatus 2 only needs to be able to form an image on a sheet, and various image forming mechanisms can be employed. In the illustrated embodiment, an electrostatic image forming mechanism is employed as the image forming mechanism. However, the image forming mechanism of the image forming apparatus 2 is not limited to the electrostatic image forming mechanism, and an ink jet image forming mechanism, an offset image forming mechanism, or the like can also be adopted.

  The image forming apparatus 2 shown in FIG. 1 includes a projector (laser head or the like) 8, a photosensitive drum 9, a developing device 10, a transfer charger 11, and a fixing roller 12. An electrostatic latent image (still image) is formed on the surface of the photosensitive drum 9 by the projector 8, toner is attached to the electrostatic latent image by the developing device 10, and the toner attached on the photosensitive drum 9 is fed into the paper feed cassette. The image is transferred by the transfer charger 11 to the sheet supplied from 7a, 7b or the sheet feeding device 5. The sheet onto which the toner has been transferred is sent to a fixing roller 12 disposed on the downstream side, and after the toner on the sheet is heated and fixed, the sheet is discharged to the sheet stacking device 6 by a pair of discharge rollers 13.

  Each of the sheet feeding cassettes 7a and 7b includes a feeding roller 14 that feeds the sheet in contact with the uppermost surface of the stored sheet, and a separation roller pair 15 that feeds the fed sheet separately. Is provided. The sheets fed from the paper feed cassettes 7 a and 7 b by the feed roller 14 and separated one by one by the separation roller pair 15 are transported by the transport roller pair 16 and sent to the transfer charger 11 along the transport path 17. Further, the sheet fed from the sheet feeding device 5 is carried into the conveyance path 17 by the carry-in roller pair 16 a and is similarly sent to the transfer charger 11 along the conveyance path 17 by the conveyance roller pair 16.

  A manual feed tray 18 is provided on the side of the image forming apparatus 2. The manual feed tray 18 is normally arranged in a closed state so as to be along the side portion of the image forming apparatus 2. When manually feeding sheets, the manual feed tray 18 is disposed in an open state from the side of the image forming apparatus 2 so that the sheets placed on the manual feed tray can be carried into the conveyance path 17. .

  A first platen 19 and a second platen 20 made of transparent glass are juxtaposed in the horizontal direction above the document reading device 3. The first platen 19 is used for reading a document set manually, and is formed to a size that allows a maximum size document to be placed thereon. The second platen 20 is used for reading a document fed from the document feeding device 4 and moving at a predetermined speed.

  Inside the document reading device 3, there are provided first and second reading carriages 21 and 22, photoelectric conversion means having a condenser lens 23 and a photoelectric conversion element 24. The first reading carriage 21 and the second reading carriage 22 are driven by a carriage motor (not shown) to reciprocate below the first platen 19 in the sub-scanning direction.

  The first reading carriage 21 is provided with a lamp that irradiates light toward the document and a mirror that reflects light reflected from the document. The second reading carriage 22 is provided with two mirrors for guiding light from the mirror of the first reading carriage 21 to the condenser lens 23 and the photoelectric conversion element 24. When reading the original on the first platen 19, the first reading carriage 21 and the second reading carriage 22 are moved and placed on the first platen 19 from the first reading carriage 21. By irradiating the image of the original with light, the reflected light from the original is guided to the photoelectric conversion element 24 via the first reading carriage 21 and the second reading carriage 22 and converted into an electrical signal, thereby converting the original from the original. Generate image data.

  The image forming apparatus 2 is provided with a control panel 25, an image data storage unit 26, and a buffer memory 27. The type of sheet on which an image is formed can be set using the control panel 25 together with image forming conditions such as color printing / monochrome printing, number of copies, single-sided printing / double-sided printing, enlarged / reduced printing, and the like. . The image data storage unit 26 stores the image data read by the document reading device 3 and converted by the photoelectric conversion element 24 as described above. The image data storage unit 26 can also store image data transferred through a network, for example. The image data stored in the image data storage unit 26 is transferred to the buffer memory 27 and is sequentially transmitted from the buffer memory 27 to the projector 8.

  The document feeder 4 includes a paper feed tray 28, a sheet transport mechanism 29, and a paper discharge tray 30. The originals placed on the paper feed tray 28 are conveyed one by one by the sheet conveying mechanism 29, pass over the second platen 20, and are discharged to the paper discharge tray 30. When reading a document fed from the document feeder 4 and passing over the second platen 20, the first reading carriage 21 and the second reading carriage 22 are stopped in advance below the second platen 20. In addition, image data is generated from a document passing over the second platen 20.

  Next, the structure of the paper feeding device 5 will be described in detail with reference to FIGS. The paper feeding device 5 includes a housing 31 including a housing main body 31 a disposed on the image forming apparatus 2 side and a housing extension 31 b extending from the upper portion of the housing main body 31 a in a direction away from the image forming apparatus 2. A storage 33 supported in the casing main body 31a so as to be able to be pulled out in a direction orthogonal to a paper feeding direction (a direction in which a sheet is fed from the paper feeding device 5 to the image forming apparatus 2) by a drawer mechanism 32; A separation sheet feeding mechanism 34 that separates the sheets in the sheet 33 and supplies them to the image forming apparatus 2 and a control device 35 that controls the sheet feeding apparatus 5 are provided. A stacking tray 36 that can be moved up and down is provided in the storage 33. A frame 37 that supports the housing extension 31b is provided below the housing extension 31b. The stacking tray 36 is a flat plate member that can stack the first type of sheet (hereinafter referred to as “normal size sheet”) on the stacking tray 36.

  A stacking tray lower limit detector 38 that detects that the stacking tray 36 has reached the lower limit position of the maximum ascending / descending range is provided at the bottom of the storage case 33, and when the stacking tray lower limit detector 38 detects the stacking tray 36. The lowering of the stacking tray 36 is stopped. A first upper surface detector 39 for detecting the uppermost surface of the sheets stacked on the stacking tray 36 is provided at the upper part of the storage 33, and the lifting tray 40 moves the stacking tray 36 according to the amount of sheets. It is designed to move.

  The housing extension 31b extending from the upper portion of the housing main body 31a in the direction away from the image forming apparatus 2 is positioned such that the upper surface (stacking surface) of the stacking tray 36 is higher than the bottom surface of the housing extension 31b. Sometimes, the rear end portion of the sheet in the sheet feeding direction protruding from the stacking tray 36 can be stored. As a result, the sheet feeding device 5 stores the second type of sheet (hereinafter referred to as “long sheet”) that is larger than the normal size sheet and protrudes from the stacking tray 36, and is stored in the image forming apparatus 2. It can be supplied.

  In the illustrated first embodiment, the lifting mechanism 40 corresponds to a plurality of wires fixed to the support portion of the stacking tray 36 (in FIG. 2, only one wire is shown in a simplified manner). A winding pulley that winds the wire to be wound, an intermediate pulley that winds a wire extending between the winding pulley and the corresponding support portion, and a lifting motor M1 that rotationally drives the winding pulley. However, the raising / lowering mechanism 40 is not particularly limited as long as it can raise and lower the stacking tray 36 while maintaining a substantially horizontal state.

  The storage 33 has a substantially box shape with an opening at the top, and when being pulled out from the housing 31, the sheet is loaded onto the stacking tray 36 in the storage 33 through the opening. , Can be loaded. A notch 33a is provided in the upper part of the side wall of the storage 33 on the housing extension 31b side, and a space for storing the stacking tray 36 inside the storage 33 (hereinafter referred to as “loading tray storage space”). Is communicated with the housing extension 31b. The notch 33a is sized to allow the long sheet to protrude from the storage 33 and extend into the housing extension 31b.

  In the stacking tray accommodation space, side end regulating members 41a and 41b positioned with the sheets on the stacking tray 36 sandwiched in the width direction (direction orthogonal to the sheet feeding direction), and the back of the normal size sheet on the stacking tray 36 A rear end regulating member 42 is further provided on the end (end on the side far from the image forming apparatus 2 in the paper feeding direction). The sheet on the stacking tray 36 is regulated by the side edge regulating members 41a and 41b at the positions of both side edges in the width direction. In the case of a normal size sheet, the position of the trailing edge in the paper feeding direction is regulated by the trailing edge regulating member 42. It has come to be.

  In the illustrated first embodiment, the side end regulating members 41a and 41b are erected on the bottom of the storage case 33 so as to be slidable in the sheet width direction in conjunction with each other by, for example, a rack and a pinion. It extends through windows 36a and 36b provided in the stacking tray 36 so as to allow movement. The rear end regulating member 42 is erected on the bottom of the storage 33 so as to be slidable in the paper feeding direction, and extends through a window 36c provided in the stacking tray 36 so as to allow movement in the paper feeding direction. Yes. With such a configuration, the side edge regulating members 41a and 41b and the rear edge regulating member 42 are moved on the bottom of the storage case 33, and the side edge position and the sheet feeding direction of the sheet on the stacking tray 36 according to the sheet size. The rear end position can be regulated.

  As shown in detail in FIG. 4, the rear end regulating member 42 is configured to be able to rotate to the downstream side in the paper feeding direction (that is, the stacking tray accommodating space side) with a fulcrum provided at the lower part as a shaft. Has been. Thereby, it is possible to prevent the trailing edge regulating member 42 from hindering the stacking when long sheets are stacked on the stacking tray 36.

  In the illustrated first embodiment, the housing extension 31b is provided only at a height position corresponding to the upper portion of the housing main body 31a. For this reason, when storing long sheets, the stacking tray 36 needs to be at a position higher than the bottom surface of the housing extension 31b. Accordingly, when the rear end regulating member 42 is turned downward from the bottom surface of the housing extension 31b when it is turned to the side of the stacking tray housing space and is turned over, the upright shown in FIG. Even if it is rotated 90 ° from the position and does not completely fall down, it does not hinder the stacking of long sheets on the stacking tray 36.

  Therefore, in the first embodiment shown in the figure, when dealing with the long sheet, it is rotated by about 60 ° from the standing position as shown in FIG. The upper end of the trailing end regulating member 42 after the fall is below the lower limit position of the stacking tray 36 when stacking long sheets and the lower limit position. Place it at a position close to This minimizes the amount of movement of the rear end regulating member 42 for accommodating a long sheet, thereby reducing labor.

  The window 36c of the stacking tray 36 is sized so that the rear end regulating member 42 can be rotated from the standing position to the falling position and from the falling position to the standing position, regardless of the height of the stacking tray 36. Is formed.

  In the illustrated first embodiment, the mode switching detection mechanism 43 further detects the rotational position of the trailing end regulating member 42, and the control unit 35 normally stores a normal size sheet in the paper feeding device 5. The sheet mode and the long sheet mode in which a long sheet is stored in the paper feeding device 5 are switched. For example, as shown in FIG. 4, the mode switching detection mechanism 43 that detects the rotational position of the rear end regulating member 42 includes a detection flag 43 a attached to the rear end regulating member 42 and the bottom plate of the storage 33. A base member 43b that is slidable upward and supports the rear end regulating member 42 so as to be rotatable, and a mode switching detector 43c provided on the base member 43b. The mode switching detector 43c may be disposed at a position where the detection flag 43a is detected when the rear end regulating member 42 is rotated to the standing position, and the flag 43a cannot be detected when the rear end regulating member 42 is rotated to the fall position. .

  Of course, switching between the normal sheet mode and the long sheet mode may be detected by another mechanism. For example, it may be performed by an operation button 44 provided on the exterior surface of the sheet feeding device 5 or may be performed from the control panel 25 of the image forming apparatus 2.

  The separation paper feeding mechanism 34 separates the fed sheets one by one from the main feeding roller 45 and the auxiliary feeding roller 61 that feed the sheets while coming into contact with the uppermost surface of the sheets stacked on the stacking tray 36. Separating transporting means for transporting to the forming apparatus 2. As will be described later, the auxiliary feeding roller 61 selectively performs main feeding in accordance with the type of sheets stacked on the stacking tray 36 (in this embodiment, when the stacked sheets are long sheets). It is configured to cooperate with the roller 45. The separation / conveying means includes a paper feed roller 46 and a separation roller 47 that presses against the paper feed roller 46 and prevents the second and subsequent sheets from being supplied.

  The sheet feeding roller 46 and the separation roller 47 are provided in the storage 33 in order to sandwich and convey sheets fed from the stacking tray 36 from above and below by the main feeding roller 45 (depending on the type of sheet and the auxiliary feeding roller 61). It is arranged at a position slightly away from the upper end toward the paper feeding direction. The paper feed roller 46 is driven by a paper feed motor M2 through a plurality of gears and timing belts (not shown), and rotates by the drive of the paper feed motor M2 to supply sheets.

  As for the separation roller 47, the torque limiter (not shown) is attached to the rotating shaft. As a result, when two or more sheets are overlapped and nipped at the pressure contact portion between the paper feed roller 46 and the separation roller 47, the separation roller 47 stops and the supply of the second and subsequent sheets from the top is prevented. It has become. That is, when a plurality of sheets overlap and enter the nip portion between the paper feed roller 46 and the separation roller 47, the driving force of the paper feed roller 46 is transmitted to the uppermost sheet, while the rotation of the separation roller 47 is stopped. Then, slip occurs between the uppermost sheet and the second and subsequent sheets from above, and the uppermost sheet and the second and subsequent sheets from the top are separated. Of course, instead of the separation roller 47, other members such as a separation pad may be used.

  The main feeding roller 45 is rotatably supported by a bracket 48 that is rotatably supported around the shaft of the paper feed roller 46 and is disposed above the stacking tray 36 on the upstream side of the paper feed roller 46 in the paper feed direction. Has been. The main feed roller 45 is driven to rotate by the rotation of the shaft of the paper feed roller 46 by the paper feed motor M2 being transmitted through a plurality of gears. In addition, the main feeding roller 45 can be moved around the shaft of the paper feed roller 46 between an operation position in contact with the upper surface of the sheet and a standby position away from the upper surface of the sheet. In this embodiment, the operation of the solenoid 49 is switched between operation and stop so that the bracket 48 is rotated around the shaft of the paper feed roller 46 and the main feeding roller 45 is moved between the operation position and the standby position. .

  An extension tray 50 that supports a rear end portion of the long sheet protruding from the stacking tray 36 in the sheet feeding direction is disposed in the housing extension 31b. The extension tray 50 is integrally connected to the stacking tray 36 when a long sheet is stored in the sheet feeding device 5. As a result, the extension tray 50 can be moved up and down integrally with the stacking tray 36. In the present embodiment, a plurality of female screw holes are provided in the upstream side surface (the right side surface in FIG. 3) of the stacking tray 36 in the sheet feeding direction, and a plurality of penetrations extending through the extension tray 50 in the sheet feeding direction. A connecting shaft 51 having a hole provided at a position corresponding to the female screw hole of the stacking tray 36 and having a male screw portion formed at the tip is inserted into each through hole of the extension tray 50, and the male at the tip of the connecting shaft is inserted. The stacking tray 36 and the extension tray 50 are connected by screwing a screw portion into the female screw hole on the side surface of the stacking tray 36.

  As shown in FIGS. 2 and 3, the auxiliary feeding roller 61 is disposed in the housing extension 31 b so as to be positioned slightly upstream from the upstream end of the extension tray 50 in the sheet feeding direction. As with the main feeding roller 45, the auxiliary feeding roller 61 is rotatably supported at the tip of a bracket 63 that is rotatably supported around a shaft 62 that extends in the sheet width direction within the housing extension 31b. ing. A driving shaft 64 extending in the sheet width direction is rotatably inserted at the front end of the bracket 63, and the feeding roller 61 is attached to the driving shaft 64 so as to rotate integrally. The drive shaft 64 is connected to the second paper feed motor M3 through a plurality of gears and timing belts (not shown). When the second paper feed motor M3 is rotated, the auxiliary feeding roller 61 is driven to rotate. ing.

  Furthermore, the auxiliary feeding roller 61 protrudes from the stacking tray 36 and comes into contact with the upper surface of the rear end portion in the sheet feeding direction of the long sheet supported on the extension tray 50, and the standby position away from the upper surface. It is possible to move it around the shaft 62. In the present embodiment, similarly to the main feeding roller 45 described above, by switching the operation and stop of the solenoid 65, the bracket 63 is rotated around the shaft 62, and the auxiliary feeding roller 61 is moved between the operating position and the standby position. Move between.

  In the present embodiment, as shown in FIG. 3, the auxiliary feeding roller 61 is composed of a pair of rollers 61 a and 61 b mounted coaxially on the drive shaft 64 at a predetermined distance in the sheet width direction. Yes. One main feeding roller 45 is arranged on the center line C in the sheet width direction of the stacking tray 36 and the extension tray 50, whereas the auxiliary feeding rollers 61a and 61b have a center line C in the sheet width direction. They are placed symmetrically across. When the main feeding roller 45 and the auxiliary feeding rollers 61a and 61b arranged in this way cooperate, when feeding the sheets from the stacking tray 36 and the extension tray 50, the sheet skew, that is, the sheet direction with respect to the sheet feeding direction. Misalignment and misalignment in the sheet width direction can be effectively prevented or reduced.

  The outer wall portion on the front side (front side in FIG. 2) of the housing extension portion 31 b is formed integrally with the front side exterior portion of the storage case 33, and the case extension portion as the storage case 33 is pulled out. It is configured to be separated from 31b. Therefore, even when the extension tray 50 is connected to the stacking tray 36, the extension tray 50 can be pulled out from the housing extension 31b as the storage case 33 is pulled out.

  In the housing extension 31b, long sheet side end regulating members 52a and 52b for regulating the positions of both side ends in the sheet width direction of the rear end portion of the long sheet in the sheet feeding direction, and the feeding of the long sheet A long sheet rear end regulating member 53 that regulates the position of the rear end in the direction is provided on the extension tray 50. In the illustrated embodiment, the long sheet side end regulating members 52a and 52b are mounted on the extension tray 50 so as to be slidable in the width direction of the long sheet in conjunction with each other by, for example, a rack and a pinion. . The long sheet trailing edge regulating member 53 is mounted on the extension tray 50 so as to be slidable in the sheet feeding direction of the long sheet.

  An extension tray lower limit detector 54 that detects that the extension tray 50 that moves up and down together with the stacking tray 36 has reached the lowest position in the casing extension 31b is provided at the bottom of the casing extension 31b. When the extension tray lower limit detector 54 detects the extension tray 50, the controller 35 stops the lowering of the stacking tray 26. Further, when a normal size sheet that can be stored in the storage 33 is stored in the sheet feeding device 5, if the extension tray lower limit sensor 54 detects the extension tray 50, it is recognized that the extension tray 50 has been forgotten to be removed from the stacking tray 36. It is also possible to notify. Further, in the housing extension 31b, a second upper surface detector is used to detect the uppermost surface of the rear end portion in the sheet feeding direction of the long sheet that protrudes from the stacking tray 36 and is supported on the extension tray 50. 66 is provided.

  The second upper surface detector 66 can be constituted by a detection sensor that detects a sensor flag (not shown) provided near the tip of the bracket 63, for example. This detection sensor is supported on the extension tray 50 by detecting the sensor flag when the uppermost surface of the long sheet on the extension tray 50 contacts the auxiliary feeding roller 61 and the bracket 63 rotates upward. The uppermost surface of the long sheet is detected. At least the second upper surface detector 66 is arranged so that it can be reliably detected when the uppermost surface of the long sheet on the extension tray 50 is in the sheet feeding position.

  On the other hand, the second upper surface detector 66 does not detect the sensor flag of the bracket 63 when there is no long sheet on the stacking tray 36 and the extension tray 50. Therefore, when the long sheet mode is set, it can be confirmed by the second upper surface detector 66 whether the sheet stacked on the stacking tray 36 is a long sheet.

  The control device 35 includes a sheet information acquisition unit 35a, a stacking tray control unit 35b, a height position setting unit 35c, a lower limit position setting unit 35d, and a paper feed control unit 35e. The sheet information acquisition unit 35 a acquires information related to the type of sheets stacked on the stacking tray 36. The stacking tray control unit 35 b controls the lifting / lowering operation of the stacking tray 36, and the sheet feeding control unit 35 e controls the operation of the separation sheet feeding mechanism 34.

  Based on the sheet type acquired by the sheet information acquisition unit 35a, the height position setting unit 35c is configured to stop the stacking tray when a new sheet is stacked on the stacking tray 36 (hereinafter referred to as “stacking”). Set “Ready position”. The lower limit position setting unit 35d sets the lower limit position of the elevation range of the stacking tray 36 based on the sheet type acquired by the sheet information acquisition unit 35a. The normal sheet setting position, which is a stacking preparation position in the case of a normal size sheet, is defined between the bottom surface of the housing body 31a and the bottom surface of the housing extension 31b. The long sheet setting position, which is the stacking preparation position in the case of long sheets, is defined at a position higher than the bottom surface of the housing extension 31b.

  The stacking tray control unit 35b is configured such that, for example, the storage 33 is in the casing 31 in a state where no sheet is detected by the sheet detector 56 provided on the stacking tray 36 (that is, no sheet is stacked on the stacking tray 36). Set by the height position setting unit 35c when a new sheet is stacked on the stacking tray 36, such as when it is stored inside or when the storage case 33 is pulled out from the housing 31 for sheet replenishment. The loading tray 36 is moved to the loaded loading preparation position. Further, when the stacking tray control unit 35b lowers the stacking tray 36, when the stacking tray 36 reaches the lower limit position set by the lower limit position setting unit 35d, the stacking tray control unit 35b stops the lowering of the stacking tray 36.

  In the sheet feeding device 5 of the first embodiment, the sheet information acquisition unit 35a of the control device 35 is stacked on the stacking tray 36 by detecting the switching of the normal sheet mode or the long sheet mode by the mode switching detection mechanism 43. Information on whether the type of the sheet to be used is a normal size sheet or a long sheet is acquired. However, the sheet information acquisition unit 35a uses the operation button 44 of the sheet feeding device 5 or the control panel 25 of the image forming apparatus 2 to select the sheet type such as whether the sheet stacked on the stacking tray 36 is a normal size sheet or a long sheet. You may acquire the information about.

  In the sheet feeding device 5 according to the first embodiment, in the normal sheet mode, the lower limit position setting unit 35d selects the stacking tray lower limit detector 38 and detects the stacking tray 36 detected by the stacking tray lower limit detector 38. The position is set as the lower limit position, and the height position setting unit 35c sets the lower limit position of the stacking tray 36 detected by the stacking tray lower limit detector 38 as the normal sheet setting position. Thereby, the stacking tray control unit 35b raises the stacking tray 36 by a predetermined amount from the upper limit position (the height position at which the sheet on the stacking tray 36 is detected by the first upper surface detector 39) when the sheet is a normal size sheet. Position) and the lower limit position detected by the stacking tray lower limit detector 38, the stacking tray 36 is moved up and down. Further, the stacking tray control unit 35b moves the stacking tray 36 to the lower limit position detected by the stacking tray lower limit detector 38 when a new normal size sheet is replenished and stacked on the stacking tray 36.

  On the other hand, in the long sheet mode, the lower limit position setting unit 35d selects the extension tray lower limit detector 54 and sets the position of the extension tray 50 detected by the extension tray lower limit detector 54 as the lower limit position. The position setting unit 35c sets the position of the stacking tray 36 when the extension tray 50 is detected by the extension tray lower limit detector 54 as the long sheet setting position. As a result, the stacking tray control unit 35b lifts the stacking tray 36 by a predetermined amount from the upper limit position (the height position at which the sheet on the stacking tray 36 is detected by the first upper surface detector 39) for a long sheet. Position) and the lower limit position detected by the extension tray lower limit detector 54, the stacking tray 36 and the extension tray 50 are moved up and down. The stacking tray 35 control unit b moves the stacking tray 36 and the extension tray 50 to the lower limit position detected by the extension tray lower limit detector 54 when a long sheet is newly replenished and stacked on the stacking tray 36.

  In the sheet feeding device 5 configured as described above, in the normal sheet mode for feeding a normal size sheet, the connection between the stacking tray 36 and the extension tray 50 is released as shown in FIG. Then, the rear end regulating member 42 is raised and the normal size sheets are stacked on the stacking tray 36 in the storage 33. The stacking tray 36 is raised until the uppermost normal size sheet reaches a predetermined height, and can be fed to the image forming apparatus 2 by the separation feeding mechanism 34. When the sheets are fed from the stacking tray 36 in this state, only the main feeding roller 45 of the separation paper feeding mechanism 34 is driven to rotate.

  On the other hand, in the long sheet mode in which long sheets are fed, as shown in FIG. 6, the stacking tray 36 is raised above the bottom surface of the housing extension 31b, and the rear end regulating member 42 is moved. In order not to hinder the stacking of long sheets, the leading end of the sheet is rotated to the fall position positioned below the stacking tray 36, and the extension tray 50 is connected to the stacking tray 36, and then the long sheets are stacked. . At this time, the rear end portion in the sheet feeding direction of the sheet protruding from the stacking tray 36 and extending from the storage 33 is extended by the extension tray 50 connected to the side portion of the stacking tray 36 far from the image forming apparatus 2. Supported.

  As the stacking tray 36 is raised, the extension tray 50 connected thereto is also raised, so that the uppermost long sheet is raised to a predetermined height while maintaining a substantially horizontal state. 2 can be fed. When the sheets are fed from the stacking tray 36 and the extension tray 50 in this state, the separation feeding mechanism 34 is rotationally driven in synchronization with the main feeding roller 45 and the auxiliary feeding roller 61 as described later.

  As described above, the sheet feeding device 5 feeds not only a normal size sheet but also a long sheet of a size protruding from the stacking tray 36 in a state in which a large number of sheets are accommodated in the housing 31 without being exposed to the external environment. can do. Further, since the extension tray 50 is connected to the stacking tray 36, the extension tray 50 can be lifted and lowered by the lifting mechanism 40 of the stacking tray 36, and it is necessary to provide a separate lifting mechanism for lifting and lowering the extension tray 50. And the mechanism can be simplified.

  Furthermore, since the long sheet is larger and heavier than the normal size sheet, the same number of long sheets as the normal size sheet are stacked on the stacking tray 36 as compared with the case where only the normal size sheet is supported. Therefore, a larger output is required for the lifting motor M1 of the lifting mechanism 40. In the illustrated first embodiment, the housing extension 31b is provided such that the bottom surface thereof is located above the bottom surface of the housing body 31a. Therefore, when feeding a long sheet, it is necessary to move the stacking tray 36 to a position higher than the bottom surface of the housing extension 31b positioned above the bottom surface of the housing body 31a. 35b is also configured to move the stacking tray 36 to a stacking preparation position above the bottom surface of the housing extension 31b positioned above the bottom surface of the housing body 31a.

  As a result, since the amount (number of sheets) of long sheets that can be stacked on the stacking tray 36 and the extension tray 50 is smaller than that in the case of normal size sheets, the maximum stacking weight of the long sheets to be stacked can be reduced. . Therefore, it is possible to cope with a long sheet by using the lifting motor M1 having the same output as when only a normal size sheet is handled.

  Next, with reference to FIG. 7, a procedure for changing the type of sheet stored in the sheet feeding device 5 of the present embodiment will be described. When an operator presses a lock release button (not shown) of the storage 33 provided on the upper surface of the sheet feeding device 5, the storage 33 is in a state where the stacking tray 36 is lowered and the lock is released so that the storage 33 can be pulled out. It becomes. In the illustrated first embodiment, when the storage 33 is pulled out, in the normal sheet mode, the stacking tray 36 has a normal sheet setting position (that is, a lower limit detected by the stacking tray lower limit detector 38). In the long sheet mode, the stacking tray 36 is moved to the long sheet setting position (that is, the lower limit position where the extension tray 50 is detected by the extension tray lower limit detector 54). The storage case 33 is pulled out from the casing 31 of the paper feeding device 5 to the front side (front side in FIG. 2) (step S1), and if sheets remain on the stacking tray 36 in the storage case 33, the stacking tray 36 is reached. The remaining sheet is removed from the top (step S2).

  Next, when the type of the sheet stored in the sheet feeding device 5 is changed from the normal size sheet to the long sheet (step S3), the rear end regulating member 42 is erected with the storage 33 being pulled out from the housing 31. The position is turned from the position to the fall position (step S4), and the storage 33 is closed and accommodated in the casing 31 (step S5). Since the stacking tray 36 is provided with the window 36c, the rear end regulating member 42 does not interfere with the stacking tray 36 when the stacking tray 36 falls down, regardless of the position of the stacking tray 36.

  When the storage case 33 is closed, the sheet information acquisition unit 35a is unable to detect the detection flag 43a by the mode switching detection sensor 43c of the mode switching detection mechanism 43 due to the movement of the trailing end regulating member 42 to the overturned position. It is recognized that the sheet mode has been switched, that is, the stacked sheet is a long sheet, and the sheet detector 56 recognizes that there is no sheet on the stacking tray 36. Accordingly, the height position setting unit 35c sets the long sheet setting position defined at a position higher than the bottom surface of the housing extension 31b as the stacking preparation position, and the lower limit position setting unit 35d detects the extension tray lower limit detection. The height position of the stacking tray 36 when the device 54 detects the extension tray 50 is set as the lower limit position. As a result, the stacking tray control unit 35b raises the stacking tray 36 to the long sheet setting position (step S6).

  The raising of the stacking tray 36 from the normal set position to the long set position is controlled using the encoder EC shown in FIG. That is, the number of pulses of the encoder EC corresponding to the distance from the normal set position to the long set position is set in advance, and the stacking tray 36 is stopped when the number of pulses of the encoder EC reaches the set number of pulses. The elevator motor M1 is controlled. When the sheet detector 56 detects that there is a sheet on the stacking tray 36, an error or forgetting to take a sheet is notified in a state where the stacking tray is stopped without being raised.

  Switching to the long sheet mode may be recognized by selecting the long sheet mode on the control panel 25 or may be recognized by operating the operation button 44. However, in order to accommodate the long sheet in the casing 31, it is necessary to move the rear end regulating member 42 to the overturned position. Further, in order to confirm that preparation for accommodating the long sheet is made, it is preferable that the mode switching detection mechanism 43 recognizes the switching to the long sheet mode.

  When the stacking tray 36 has been raised to the long sheet setting position, the storage 33 is pulled out from the casing 31 of the sheet feeding device 5 again (step S7), and the extension tray 50 is connected to the stacking tray 36 (step S8). . The stacking tray 36 and the extension tray 50 are connected to each other through the plurality of through holes provided in the extension tray 50 with the side surface of the extension tray 50 facing the side surface of the stacking tray 36 on the rear end side in the paper feeding direction. The connecting shaft 51 is inserted into the female tray, and the male screw portion at the tip of the connecting shaft 51 is screwed into the female screw hole provided on the side surface of the stacking tray 36 on the rear end side in the sheet feeding direction. However, the connection of the stacking tray 36 and the extension tray 50 is not limited to the above method, and can be performed by various methods.

  After the extension tray 50 is connected to the stacking tray 36, long sheets are stacked on the stacking tray 36 and the extension tray 50 and set at a predetermined position (step S9). When the stacking of sheets is completed, the storage 33 is closed again and stored in the housing 31 (step S10). The long sheets on the stacking tray 36 and the extension tray 50 are moved to predetermined positions by moving the side edge regulating members 41a and 41b, the long sheet side edge regulating members 52a and 52b, and the long sheet trailing edge regulating member 53 to a predetermined position. Both side ends of the long sheet are brought into contact with the side end regulating members 41a and 41b and the long sheet side end regulating members 52a and 52b, and the rear end in the sheet feeding direction of the long sheet is used as the long sheet trailing end regulating member 53. By abutting, it is arranged at a predetermined position.

  Since the outer wall portion on the front side of the housing extension 31b is separated from the housing extension 31b when the storage 33 is pulled out, the extension tray 50 is attached to the housing when the storage 33 is pulled out. There is no interference with the outer wall of the extension 31b. In addition, the trailing edge regulating member 42 rotates the leading end to the fall position positioned below the stacking tray 36 at the long sheet setting position, so that the long sheet is transferred from the stacking tray 36 to the housing extension 31b. It does not interfere with the projecting.

  On the other hand, when the type of sheet stored in the sheet feeding device 5 is changed from the long sheet to the normal size sheet (step S3), the male at the tip of the connection shaft 51 is pulled out with the storage 33 being pulled out from the housing 31. The threaded engagement between the threaded portion and the female screw hole of the stacking tray 36 is released, the connecting shaft 51 is pulled out from the through hole of the extension tray 50, and the extension tray 50 is removed from the stacking tray 36 (step S11). Since the long sheet mode is set when the storage case 33 is pulled out, the lower limit position of the raising / lowering range of the stacking tray 36 is a position where the extension tray lower limit detector 54 detects the extension tray 50 by the lower limit position setting unit 35d. Is set to Therefore, the stacking tray 36 and the extension tray 50 are located above at least the bottom surface of the housing extension 31b.

  In the present embodiment, the position where the extension tray detector 54 detects the extension tray 50 is set as a long sheet setting position (stacking preparation position in the case of a long sheet). Therefore, the stacking tray control unit 35 b lowers the stacking tray 36 and the extension tray 50 to a position where the extension tray detector 54 detects the extension tray 50 when the storage case 33 is pulled out from the housing 31.

  Further, since the outer wall portion on the front side of the housing extension portion 31b is separated from the housing extension portion 31b along with the drawer of the storage case 33, the extension tray 50 is attached to the housing when the storage case 33 is pulled out. There is no interference with the outer wall of the body extension 31b. Next, the rear end regulating member 42 is rotated from the fall position to the standing position (step S12), and the storage 33 is closed and accommodated in the casing 31 (step S13). Since the stacking tray 36 is provided with the window 36c, the stacking tray 36 does not interfere with the stacking tray 36 when the trailing end regulating member 42 falls, regardless of the position of the stacking tray 36.

  When the storage 33 is closed, the sheet information acquisition unit 35a detects the detection flag 43a by the mode switching detection sensor 43c of the mode switching detection mechanism 43 due to the movement of the trailing end regulating member 42 to the standing position, and the normal sheet. It is recognized that the mode has been switched, that is, the stacked sheet is a normal size sheet, and the sheet detector 56 recognizes that there is no sheet on the stacking tray 36. Accordingly, the height position setting unit 35c sets the normal sheet setting position defined at the bottom of the housing main body 31a as the stacking preparation position, and the lower limit position setting unit 35d is configured such that the stacking tray 36 has the stacking tray lower limit detector. The height position detected by 38 is set as the lower limit position. As a result, the stacking tray control unit 35b lowers the stacking tray 36 to the normal sheet setting position (step S14).

  Switching to the normal sheet mode may be recognized by selecting the normal sheet mode on the control panel 25 or may be recognized by operating the operation button 44. However, the mode switching detection mechanism 43 recognizes the switching to the normal sheet mode in order to confirm that the trailing edge regulating member 42 is in the upright position and is ready to accommodate the normal size sheet. Is preferred.

  When the lowering of the stacking tray 36 to the normal sheet setting position is completed, the storage 33 is pulled out from the casing 31 of the sheet feeding device 5 again (step S15), and the normal size sheets are stacked on the stacking tray 36 to a predetermined position. Set (step S16). When the stacking of sheets is completed, the storage 33 is closed again and stored in the housing 31 (step S10). For the normal size sheet on the stacking tray 36, the side end regulating members 41a and 41b and the rear end regulating member 42 are moved to predetermined positions, and both side ends of the normal size sheet are brought into contact with the side end regulating members 41a and 41b. The normal size sheet is arranged at a predetermined position by bringing the rear end in the sheet feeding direction into contact with the rear end regulating member 42 in the standing position.

  When the storage case 33 is pushed into the casing 31 and closed, the stacking tray control unit 35b arranges the uppermost surface of the sheets stacked on the stacking tray 36 at the feeding position as shown in FIG. Then, the stacking tray 36 is raised. Specifically, when the storage 33 is closed and an open / close sensor (not shown) is turned on (step S17), the stacking tray control unit 35b drives the lift motor M1 to raise the stacking tray 36 (step S18). ).

  In the normal sheet mode, the upper surface of the uppermost sheet on the rising stacking tray 36 comes into contact with the main feeding roller 45, the main feeding roller 45 is slightly lifted, and the first upper surface detector 39 is turned on (step S19). ), The stacking tray 36 is raised by a predetermined amount from the position where the first upper surface detector 39 is turned on, the lifting motor M1 is stopped, and the lifting of the stacking tray 36 is stopped (step S20). As a result, the upper surface of the uppermost sheet on the stacking tray 36 is arranged at the feeding position, and preparation for feeding is completed.

  In the case of the long sheet mode, it is confirmed whether or not the sheet on the stacking tray 36 is a long sheet when the uppermost surface of the stacked sheets is arranged at the operation position. Whether or not the sheet is a long sheet is confirmed based on the detection results of the first and second upper surface detectors 39 and 66. More specifically, when long sheets are stacked on the stacking tray 36, both the first and second upper surface detectors 39 and 66 are turned on. In this case, the sheet information acquisition unit 35a recognizes that a long sheet is stacked on the stacking tray 36, and the stacking tray control unit 35b drives the lift motor M1 to continue raising the stacking tray 36. become.

  Accordingly, the upper surfaces of the uppermost sheets on the rising stacking tray 36 and the extension tray 50 come into contact with the main feeding roller 45 and the auxiliary feeding roller 61, respectively, and the feeding rollers 45 and 61 are slightly lifted to thereby detect the first upper surface detector. 39 and the second upper surface detector 66 are turned on (step S19), the stacking tray 36 is raised by a predetermined amount from the position where both the detectors 39 and 66 are turned on, the lifting motor M1 is stopped, and the stacking tray 36 is stopped. And the raising of the extension tray 50 is stopped (step S20). As a result, the top surfaces of the uppermost sheets on the stacking tray 36 and the extension tray 50 are arranged at the feeding position, and preparation for feeding is completed.

  On the other hand, when the first upper surface detector 39 is turned ON and the second upper surface detector 66 is OFF, the sheet information acquisition unit 35a indicates that the normal size sheets are stacked on the stacking tray 36. Recognize and inform the user that it does not match the set sheet type. Therefore, the stacking tray control unit 35b stops the raising / lowering motor M1 and stops the lifting of the stacking tray 36.

  Next, with reference to FIGS. 9 to 11, a process from when the upper surface of the uppermost sheet on the stacking tray 36 is arranged at the feeding position to when paper feeding is performed will be described.

  As shown in FIG. 9, in both the normal sheet mode and the long sheet mode, after the upper surface of the uppermost sheet on the stacking tray 36 is arranged at the feeding position, the feeding from the image forming apparatus 2 is performed in step S21. When there is no paper signal and a predetermined time elapses (step S22), the stacking tray control unit 35b drives the lifting motor M1 to the rest position where the upper surface of the uppermost sheet on the stacking tray 36 is separated from the main feeding roller 45. Then, the stacking tray 36 is lowered by a predetermined amount and stopped (step S23). In the long sheet mode, the upper surface of the uppermost sheet on the stacking tray 36 moved to the rest position is separated from both the main feeding roller 45 and the auxiliary feeding roller 61.

  In this way, the upper surface of the uppermost sheet on the stacking tray 36 is put on standby at a rest position where the upper surface of the sheet is separated from the main feeding roller 45, so that the roller can be placed on the upper surface of the sheet even if the sheet feeding operation is not performed for a long time It is possible to prevent traces from being left. Further, in the case of the long sheet mode, the roller trace of the auxiliary feeding roller 61 is also prevented on the upper surface of the sheet feeding direction rear end side portion of the sheet supported on the extension tray 50.

  When a paper feed signal is received from the image forming apparatus 2 (step S24), the stacking tray control unit 35b drives the lifting motor M1 to raise the stacking tray 36 (step S25). When the stacking tray 36 rises and the upper surface of the uppermost sheet on the stacking tray 36 comes into contact with the main feeding roller 45 and the first upper surface detector 39 is turned on (step S26), the stacking tray control unit 35b reads the stacking tray. 36 is raised by a predetermined amount from the time when the first upper surface detector 39 is turned on to stop the raising / lowering motor M1, and the raising of the stacking tray 36 is stopped (step S27). Thereby, the upper surface of the uppermost sheet on the stacking tray 36 is arranged at the feeding position, and the sheet on the stacking tray 36 is fed out by the main feeding roller 45 (in the case of the long sheet mode and the auxiliary feeding roller 61). The sheet feeding operation (step S28) described later is performed.

  On the other hand, after the upper surface of the uppermost sheet on the stacking tray 36 is arranged at the feeding position and before the predetermined time elapses, when the control unit 35 receives a paper feed signal in step S21, a paper feed operation (step S29 described later) is performed. ) Is executed.

  The above process is repeatedly executed until the paper feed process becomes unnecessary (step S30).

  In the sheet feeding operation in the normal sheet mode shown in FIG. 10, the sheet feeding control unit 35e feeds the sheet with the upper surface of the uppermost sheet on the stacking tray 36 placed at the feeding position and in contact with the main feeding roller 45. The paper motor M2 is driven to rotate the main feeding roller 45 and the paper feeding roller 46. As a result, the uppermost sheet is fed from the stacking tray 36 by the main feeding roller 45, separated into one sheet by the sheet feeding roller 46 and the separation roller 47, and fed to the image forming apparatus 2 (step S31).

  Further, when the leading edge of the sheet to be fed is detected and turned ON by the sheet detection sensor 55 (step S32), the paper feed control unit 35e is turned on when the sheet detection sensor 55 is turned on (ie, the sheet detection sensor 55 is turned on). After the sheet is conveyed by a predetermined amount from the time when the leading edge of the sheet is detected, the solenoid 49 is operated to raise the main feeding roller 45 to the main feeding roller standby position away from the upper surface of the uppermost sheet on the stacking tray 36. (Step S33). At the same time when the main feeding roller 45 is raised, the sheet feeding motor M2 is stopped to stop the rotation of the main feeding roller 45 and the sheet feeding roller 46 (step S34).

  The leading edge of the fed normal size sheet is nipped by the pair of carry-in rollers 16a of the image forming apparatus 2 after being conveyed by a predetermined amount after being detected by the sheet detection sensor 55. In this state, the sheet is conveyed while being pulled out from the nip portion between the paper feed roller 46 and the separation roller 47 by the carry-in roller pair 16a. As described above, since the main feeding roller 45 is raised to the main feeding roller standby position and separated from the upper surface of the sheet in step S33, the pulling load when being carried into the image forming apparatus 2 by the carry-in roller pair 16a is reduced. Can be reduced. Further, it is possible to prevent the main feeding roller 45 from being contaminated with dirt and roller marks on the sheet pulled out by the carry-in roller pair 16a.

  Further, when the normal size sheet is completely carried into the image forming apparatus 2 and the sheet detection sensor 55 is turned off (step S35), that is, when the rear end in the sheet feeding direction passes the sheet detection sensor 55, the sheet feeding control is performed. The part 35e stops the operation of the solenoid 49 and lowers the main feeding roller 45 by its own weight (step S36). As described above, the normal size sheet feeding operation is performed.

  In the sheet feeding operation in the long sheet mode shown in FIG. 11, the sheet feeding control unit 35 e is arranged so that the upper surface of the uppermost sheet on the stacking tray 36 is disposed at the feeding position and contacts the main feeding roller 45 and the auxiliary feeding roller 61. In the contact state, the first paper feed motor M2 and the second paper feed motor M3 are driven to rotate the main feed roller 45, the auxiliary feed roller 61, and the paper feed roller 46 in synchronization. As a result, the main feeding roller 45 and the auxiliary feeding roller 61 cooperate to feed the uppermost sheet from the stacking tray 36, and the sheet feeding roller 46 and the separation roller 47 are separated into one sheet to form the image forming apparatus 2. (Step S41).

  Further, when the leading edge of the sheet to be fed is detected and turned on by the sheet detection sensor 55 (step S42), the paper feed control unit 35e is turned on when the sheet detection sensor 55 is turned on (ie, the sheet detection sensor 55 is turned on). After the sheet is conveyed by a predetermined amount from the time when the leading edge of the sheet is detected, the solenoid 49 and the solenoid 65 are actuated to move the main feeding roller 45 and the auxiliary feeding roller 61 from the upper surface of the uppermost sheet on the stacking tray 36, respectively. The distance is raised to the separated main feeding roller standby position and auxiliary feeding roller standby position (step S43). At the same time as the main feeding roller 45 and the auxiliary feeding roller 61 are raised, the sheet feeding motor M2 and the second sheet feeding motor M3 are stopped to stop the rotation of the main feeding roller 45, the auxiliary feeding roller 61 and the sheet feeding roller 46. (Step S44).

  The leading end of the fed long sheet in the sheet feeding direction is nipped by the pair of carry-in rollers 16a of the image forming apparatus 2 after being conveyed by a predetermined amount after being detected by the sheet detection sensor 55. In this state, the sheet is conveyed while being pulled out from the nip portion between the paper feed roller 46 and the separation roller 47 by the carry-in roller pair 16a. As described above, since the main feeding roller 45 and the auxiliary feeding roller 61 are raised to the standby position and separated from the upper surface of the sheet in step S43, they are pulled out when being carried into the image forming apparatus 2 by the carry-in roller pair 16a. The load can be reduced. Further, it is possible to prevent dirt and roller traces from being adhered to the main feeding roller 45 and the auxiliary feeding roller 61 from adhering to the sheet pulled out by the carry-in roller pair 16a.

  Even in the long sheet mode, when the long sheet is completely carried into the image forming apparatus 2 and the sheet detection sensor 55 is turned off (step S45), that is, the rear end in the sheet feeding direction causes the sheet detection sensor 55 to be turned off. When it passes, the paper feed controller 35e stops the operation of the solenoids 49 and 65, and lowers the main feeding roller 45 and the auxiliary feeding roller 61 by its own weight (step S46). The long sheet feeding operation is performed as described above.

  In the above description, the first type sheet is a normal size sheet, and the second type sheet is a long sheet. However, according to the present invention, the first type sheet is a small size sheet that can be stacked on the stacking surface of the stacking tray 36, and the second type sheet is larger than the first type sheet. Needless to say, the present invention can also be applied to a large-sized sheet that protrudes from the outside, and can be applied to a sheet feeding apparatus that handles these small-sized sheets and large-sized sheets.

  Next, the structure of the sheet feeding device 5 ′ according to the second embodiment will be described with reference to FIGS. In FIG. 12 to FIG. 14, the same reference numerals are given to components that perform the same functions as those of the paper feeding device 5 of the first embodiment.

  The paper feeding device 5 ′ of the second embodiment is different from the paper feeding device 5 of the first embodiment in that the housing extension 31 b is not provided. The sheet feeding device 5 separates the casing 31, the storage 33 supported in the casing 31 so as to be able to be pulled out in a direction orthogonal to the sheet feeding direction by a drawer mechanism, and the sheets in the storage 33 one by one. Then, a separation sheet feeding mechanism 34 that supplies the sheet to the image forming apparatus 2 and a control device 35 that controls the sheet feeding apparatus 5 ′ are provided. A stacking tray 36 that can be moved up and down is provided in the storage 33 and is moved by a lifting mechanism 40 in accordance with the amount (number of sheets) of stacked sheets. Since the configuration of the lifting mechanism 40 is the same as that of the paper feeding device 5 of the first embodiment, the description thereof is omitted here.

  The stacking tray 36 is a plate-like plate member, and is a first type sheet (hereinafter referred to as “small size sheet”) having a predetermined size or less and a second type sheet (hereinafter, referred to as “small size sheet”). Each of the “large size sheets”) can be stacked on the stacking tray 36. A first upper surface detector 39 and a second upper surface detector 66 are provided on the upper portion of the storage 33 in order to detect the uppermost surface of the sheets stacked on the stacking tray 36. The first upper surface detector 39 is disposed above the area on which the small size sheets are placed on the stacking tray 36 so as to detect the uppermost surface of the small size sheets. The second upper surface detector 66 detects the uppermost surface of the large size sheet stacked on the stacking tray 36, but places the small size sheet on the stacking tray 36 so as not to detect the uppermost surface of the small size sheet. It is arranged above the area of the large size sheet that protrudes from the area to be printed.

  The storage 33 has a substantially box shape with an opening at the top, and when being pulled out from the housing 31, the sheet is loaded onto the stacking tray 36 in the storage 33 through the opening. , Can be loaded. In the stacking tray storage space for storing the stacking tray 36 inside the storage 33, a side end regulating member (not shown) is located between the sheets on the stacking tray 36 in the width direction (direction perpendicular to the sheet feeding direction). And a trailing edge regulating member located on the trailing edge side in the sheet feeding direction of the sheets on the stacking tray 36, and the positions of both side edges in the sheet width direction on the stacking tray 36 are determined by the side edge regulating members. The position of the trailing edge of the sheet feeding direction on the stacking tray 36 is regulated by the trailing edge regulating member 42.

  In the illustrated embodiment, the side edge regulating member is erected on the bottom of the storage case 33 so as to be slidable in the sheet width direction and is provided on the stacking tray 36 so as to allow movement in the sheet width direction. The rear end regulating member 42 is erected on the bottom of the storage case 33 so as to be slidable in the paper feeding direction, and extends in the paper feeding direction, while extending through a window (not shown). It extends through a window (not shown) provided in the stacking tray 36. With such a configuration, the side edge regulating member and the rear edge regulating member 42 are moved on the bottom of the storage 33, and the side edge position of the sheet and the rear edge in the sheet feeding direction on the stacking tray 36 according to the sheet size. The position can be regulated.

  A first tray detector 57 that detects the stacking tray 36 is provided at the lowest position of the stacking tray 36 at the bottom of the storage 33. A second tray detector 58 for detecting the stacking tray 36 is provided at a position above the lowest position of the stacking tray 36 in the storage 33.

  As in the case of the first embodiment, the separation sheet feeding mechanism 34 is fed with a main feeding roller 45 and an auxiliary feeding roller 61 that are in contact with the uppermost surface of the sheets stacked on the stacking tray 36 and feed the sheets. Separating and conveying means for separating the separated sheets one by one and conveying them to the image forming apparatus 2. The separation / conveying means includes a paper feed roller 46 and a separation roller 47 that presses against the paper feed roller 46 and prevents the second and subsequent sheets from being supplied. The paper feed roller 46 is driven by a paper feed motor M2 through a plurality of gears and timing belts (not shown), and rotates by the drive of the paper feed motor M2 to supply sheets.

  The main feeding roller 45 is rotatably supported at the tip of a bracket 48 rotatably supported around the shaft of the paper feed roller 46, and the shaft of the paper feed roller 46 is rotated by a plurality of paper feed motors M2. It is transmitted via a gear and is driven to rotate. Further, the main feeding roller 45 can be moved around the shaft of the paper feed roller 46 between an operation position that contacts the upper surface of the sheet and a standby position that is separated from the upper surface of the sheet. In this embodiment, the operation of the solenoid 49 is switched between operation and stop so that the bracket 48 is rotated around the shaft of the paper feed roller 46 and the main feeding roller 45 is moved between the operation position and the standby position. .

  The auxiliary feeding roller 61 is disposed in the casing 31 so as to be located slightly upstream from the rear end in the sheet feeding direction of the small size sheets stacked on the stacking tray 36. As in the first embodiment, the auxiliary feeding roller 61 is rotatably supported at the tip of a bracket 63 that is rotatably supported around a shaft 62 that extends in the sheet width direction in the housing 31. Yes. A second paper feed motor M3 is provided in the casing 31, and rotationally drives the auxiliary feeding roller 61 via a plurality of gears and timing belts not shown.

  Further, the auxiliary feeding roller 61 is located between an operating position that contacts the upper surface of the large-sized sheet in the area of the large-sized sheet that protrudes from the area of the small-sized sheet on the stacking tray 36 and a standby position that is spaced upward from the upper surface. Thus, it can be moved around the shaft 62. In the present embodiment, similarly to the main feeding roller 45 described above, by switching the operation and stop of the solenoid 65, the bracket 63 is rotated around the shaft 62, and the auxiliary feeding roller 61 is moved between the operating position and the standby position. Move between.

  Since the configurations of the main feeding roller 45 and the auxiliary feeding roller 61 are the same as those in the first embodiment, detailed description thereof is omitted here.

  The control device 35 includes a sheet information acquisition unit 35a, a stacking tray control unit 35b, a height position setting unit 35c, a lower limit position setting unit 35d, and a paper feed control unit 35e. The sheet information acquisition unit 35a acquires information regarding the type of sheets stacked on the stacking tray 36, the stacking tray control unit 35b controls the raising / lowering operation of the stacking tray 36, and the sheet feeding control unit 35e is a separation sheet feeding mechanism. 34 is controlled. Further, the height position setting unit 35c sets the height position at which the stacking tray is stopped when a sheet is newly stacked on the stacking tray 36 based on the sheet type acquired by the sheet information acquiring unit 35a. The lower limit position setting unit 35d sets the lower limit position of the lifting / lowering range of the stacking tray 36 based on the sheet type acquired by the sheet information acquisition unit 35a.

  In the stacking tray control unit 35b, for example, the storage case 33 is placed in the casing 31 in a state in which no sheet is detected by the sheet detector 56 provided on the stacking tray 36 (that is, no sheet is stacked on the stacking tray 36). Set by the height position setting unit 35c when a new sheet is stacked on the stacking tray 36, such as when it is stored inside or when the storage case 33 is pulled out from the housing 31 for sheet replenishment. The loading tray 36 is moved to the loaded loading preparation position. In addition, when the stacking tray 36 reaches the lower limit position set by the lower limit position setting unit 35d when the stacking tray 36 is lowered, the stacking tray control unit 35 stops the lowering of the stacking tray 36.

  In the sheet feeding device 5 ′ of the second embodiment shown in the figure, the sheet information acquisition unit 35 a of the control device 35 has a predetermined size of sheets stacked on the stacking tray 36 from the control panel 25 of the image forming device 2. Information about the sheet type, such as whether the following small size sheet or a large size sheet larger than a predetermined size, is acquired. The sheet information acquired by the sheet information acquisition unit 35a may be acquired from the operation button 44 or other means. If it is information on the sheet size and the sheet length, the positions of the side end regulating member and the rear end regulating member can be detected and obtained from the detection result.

  Further, in the illustrated sheet feeding device 5 ′ of the second embodiment, in the case of a small size sheet, the lower limit position setting unit 35 d selects the first tray detector 57, and the first tray detector The height position (minimum lower limit position) of the stacking tray 36 detected by 57 is set as the lower limit position, and the height position setting unit 35c detects the height position of the stacking tray 36 detected by the first tray detector 57. Is set as the loading preparation position. As a result, the stacking tray control unit 35b lifts the stacking tray 36 by a predetermined amount from the upper limit position (height position at which the sheet on the stacking tray 36 is detected by the first upper surface detector 39) for a small size sheet. Position) and the lower limit position detected by the first tray detector 57, the stacking tray 36 is moved up and down. Further, when the stacking tray control unit 35b newly replenishes and stacks small size sheets on the stacking tray 36, the stacking tray 36 is detected by the first tray detector 57 as shown in FIG. The stacking tray 36 is moved to the lower limit position.

  On the other hand, in the case of a large size sheet larger than the small size sheet, the lower limit position setting unit 35d selects the second tray detector 58 and the height of the stacking tray 36 detected by the second tray detector 58. The position is set as the lower limit position, and the height position setting unit 35c sets the height position of the stacking tray 36 detected by the second tray detector 58 as the stacking preparation position. As a result, the stacking tray control unit 35b lifts the stacking tray 36 by a predetermined amount from the upper limit position (the height position at which the sheet on the stacking tray 36 is detected by the first upper surface detector 39) when the sheet is a large size sheet. Position) and the lower limit position where the stacking tray 36 is detected by the second tray detector 58, the stacking tray 36 is moved up and down. Further, when the stacking tray 35 controller b newly stacks a large size sheet on the stacking tray 36, the stacking tray 36 is detected by the second tray detector 58 as shown in FIG. The stacking tray 36 is moved to the lower limit position.

  Large-size sheets are larger and heavier than small-size sheets. Therefore, when the same number of sheets as small-size sheets are stacked on the stacking tray 36, a larger output is produced compared to the case where only small-size sheets are supported. Forty elevating motors M1 are required. However, in the sheet feeding device 5 ′ of the second embodiment, when a small-size sheet is newly stacked, as illustrated in FIG. 13, the stacking height is h <b> 1. While the stacking tray 36 is lowered to the preparation position, when a large size sheet is newly stacked, as shown in FIG. 14, the height at which the sheet can be stacked becomes h2 smaller than h1. The loading tray 36 is lowered only to the loading preparation position. Further, the lower limit position of the raising / lowering range of the stacking tray 36 is similarly determined. As a result, the maximum amount of large size sheets that can be stacked on the stacking tray 36 is smaller than in the case of small size sheets, so the maximum stacking weight of large size sheets to be stacked can be reduced, and only small size sheets can be reduced. It is possible to handle a large size sheet by using the same lift motor M1 as in the case of handling the sheet.

  In the sheet feeding device 5 ′ of the second embodiment, the processing and feeding operation performed at the time of feeding each of the small size sheet and the large size sheet are the normal size in the sheet feeding device 5 of the first embodiment. Since it is the same as that of the sheet and the long sheet, the description is omitted here.

  Hereinafter, with reference to FIG. 15, a procedure for changing the type of sheet stored in the sheet feeding device 5 ′ of the second embodiment will be described.

  First, the setting of the sheet type (here, the sheet size) based on the sheet size, material, and the like is changed by the control panel 25 and the operation button 44, and the sheet information acquisition unit 35a of the control device 35 changes the sheet information. Information on the type is acquired (step S51). Next, the storage case 33 is pulled out from the casing 31 of the paper feeding device 5 to the front side (front side in FIG. 12) (step S52), and if sheets remain on the stacking tray 36 in the storage case 33, The remaining sheets are removed from the stacking tray 36 (step S53).

  When the lock of the storage 33 is released before the storage 33 is pulled out, the stacking tray 36 is moved to the stacking preparation position corresponding to the sheet type set before the setting change. In the sheet feeding device 5 ′ of the second embodiment shown in the figure, the stacking tray 36 is detected by the first tray detector 57 when the sheet type set before the setting change is a small size sheet. When the stacking tray 36 is moved to the lower limit position shown in FIG. 13 and the sheet type set before the setting change is a large size sheet, the stacking tray 36 is detected by the second tray detector 58. The stacking tray 36 is moved to the lower limit position shown in FIG.

  When there is no sheet on the stacking tray 36, the storage 33 is closed and stored in the housing 31 (step S54). When the storage case 33 is closed, the sheet detector 56 recognizes that there is no sheet on the stacking tray 36. Accordingly, based on the sheet type information acquired by the sheet information acquisition unit 35a, the height position setting unit 35c sets the height position according to the sheet type as the stacking preparation position, and the lower limit position setting unit 35d. The height position corresponding to the type of sheet is set as the lower limit position.

  In the sheet feeding device 5 ′ of the second embodiment shown in the figure, in the case of a small size sheet, the lower limit position setting unit 35 d selects the first tray detector 57, and uses the first tray detector 57. The detected height position (lowest limit position) of the stacking tray 36 is set as the lower limit position, and the height position setting unit 35c loads the height position of the stacking tray 36 detected by the first tray detector 57. Set as preparation position. In the case of a large size sheet, the lower limit position setting unit 35d selects the second tray detector 58, sets the height position of the stacking tray 36 detected by the second tray detector 58 as the lower limit position, The height position setting unit 35c sets the height position of the stacking tray 36 detected by the second tray detector 58 as the stacking preparation position. As a result, the stacking tray control unit 35b moves the stacking tray 36 up and down to the stacking preparation position set by the height position setting unit 35c according to the sheet type (step S55).

  When the raising / lowering of the stacking tray 36 to the stacking preparation position is completed, the storage 33 is pulled out again from the casing 31 of the sheet feeding device 5 '(step S56), and the type of sheet set in step S51 is stacked on the stacking tray 36. Then, it is set at a predetermined position (step S57), and when loading is completed, the storage 33 is closed again and stored in the housing 31 (step S58). The sheets on the stacking tray 36 move a side end regulating member (not shown) and a trailing end regulating member 42 to predetermined positions so that both side edges of the sheet come into contact with the side end regulating member and the sheet is fed. The rear end in the paper direction is brought into contact with the rear end regulating member 42 to be disposed at a predetermined position.

  When the storage case 33 is pushed into the casing 31 and closed, the stacking tray control unit 35b follows the steps S17 to S20 shown in FIG. 8 as in the case of the first embodiment. The upper surface of the uppermost sheet on 36 is arranged at the feeding position, and the preparation for feeding is completed.

  In the sheet feeding devices 5 and 5 ′ in the above embodiments, the types of sheets supplied to the image forming apparatus 2 are classified based on the sheet size, and the auxiliary feeding roller 61 that cooperates with the main feeding roller 45 is selectively driven. doing. However, in the present invention, the sheet type other than the sheet size, that is, sheet thickness (weight), material (plain paper, glossy paper, recycled paper, plastic sheet, etc.), properties (hardness, stiffness, surface smoothness) Etc.), and various types of processed products according to the application. Regardless of the type of sheet, according to the present invention, by cooperating the main feeding roller and the auxiliary feeding roller, the sheet always has a sufficient sheet conveying force without causing damage such as roller marks on the sheet. It can be demonstrated and can be fed out and supplied reliably and smoothly from the stacking tray.

  Also in other configurations, the present invention is not limited to the illustrated embodiment, and can be implemented with various changes and modifications within the technical scope thereof. For example, in the above-described embodiment, the sheet feeding devices 5 and 5 ′ are disposed adjacent to the image forming apparatus 2, but can be incorporated into the image forming apparatus 2 similarly to the sheet feeding cassette 7. Further, a control device (control means) 35 for controlling the paper feeding devices 5 and 5 ′ including raising and lowering of the stacking tray 36 and the operation of the separation paper feeding mechanism is either inside or outside the housing of the paper feeding devices 5 and 5 ′. You may install in. For example, the control device 35 can be disposed in the image forming apparatus 2 of the paper feeding device 5 or 5 ′, and an actuator such as the lifting motor M <b> 1 can be driven and controlled from the image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Image forming system 2 Image forming apparatus 5 Paper feeder 31 Case 31a Case main-body part 31b Case extension part 33 Storage 35 Control part 36 Stack tray 38 Stack tray lower limit sensor 39 1st upper surface detector 42 Rear end regulation member 45 Main feeding roller 50 Extension tray 54 Extension tray lower limit sensor 56 Sheet detector 57 First tray detector 58 Second tray detector 61 Auxiliary feeding roller 66 Second upper surface detector

Claims (13)

A sheet stacking tray for stacking sheets;
A main feeding roller for feeding out the sheets on the sheet stacking tray in the sheet supply direction;
An auxiliary feeding roller disposed upstream of the main feeding roller in the sheet feeding direction in order to feed the sheet on the sheet stacking tray in the sheet feeding direction;
Driving means for driving the main feeding roller and the auxiliary feeding roller,
The driving means drives the main feeding roller to feed the sheets on the sheet stacking tray without driving the auxiliary feeding roller corresponding to the type of the sheet on the sheet stacking tray. A sheet supply mechanism that selectively executes a feeding operation and a second feeding operation of driving the main feeding roller and the auxiliary feeding roller to feed out the sheets on the sheet stacking tray.   The sheet feeding mechanism according to claim 1, wherein the driving unit drives the auxiliary feeding roller so as to cooperate with the main feeding roller in the second feeding operation.   The type of the sheet is a length of the sheet, and when the length of the sheet is longer than a predetermined length, the driving unit performs the second feeding operation. The sheet supply mechanism according to 1 or 2.   The sheet supply mechanism according to claim 3, further comprising a long sheet detecting unit that detects that the length of the sheet on the sheet stacking tray is longer than the predetermined length.   The sheet feeding mechanism according to claim 4, wherein the long sheet detecting unit detects a position of the auxiliary feeding roller that is in contact with an uppermost surface of the sheet on the sheet stacking tray.   The sheet supply mechanism according to claim 1, further comprising an input unit configured to input a type of the sheet on the sheet stacking tray.   The auxiliary feeding roller is disposed at a position that does not overlap the main feeding roller in a sheet width direction perpendicular to the sheet feeding direction along the sheet feeding direction. The sheet supply mechanism according to 1.   8. The apparatus according to claim 1, further comprising an extension tray for stacking and supporting a portion of the sheet on the sheet stacking tray that protrudes upstream of the predetermined length in the sheet supply direction. The sheet supply mechanism described.   The sheet supply mechanism according to claim 8, wherein the extension tray is detachably provided on the sheet stacking tray.   The sheet supply mechanism according to claim 1, further comprising a control unit that controls the driving unit such that the driving unit executes the first and second feeding operations.   2. The sheet feeding mechanism according to claim 1, wherein the driving unit includes a first driving unit that drives the main feeding roller and a second driving unit that drives the auxiliary feeding roller. 3.   A sheet supply apparatus comprising the sheet supply mechanism according to any one of claims 1 to 11, for supplying sheets on the sheet stacking tray in the sheet supply direction.   An image forming apparatus comprising the sheet supply mechanism according to any one of claims 1 to 11 or the sheet supply device according to claim 12, in order to supply a sheet on the sheet stacking tray to an image forming unit.

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