JP5521461B2 - Recording medium supply apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a recording medium supply device that supplies a sheet-like recording medium, and an image forming apparatus including the recording medium supply device.

  2. Description of the Related Art In image forming apparatuses such as copying machines, printers, facsimiles, and multifunction machines of these, paper feeding apparatuses that supply paper, OHP films, etc. one by one are known. In the paper feeder, air is blown onto the bundle of paper stacked on the tray to float the paper (recording paper) and separate it from each other, and the uppermost paper is attracted to the suction belt by suction and conveyed. There is an air separation paper feeder. Examples of conventional air separating and feeding apparatuses include those described in Patent Document 1 (Japanese Patent No. 4003073) and Patent Document 2 (Japanese Patent Laid-Open No. 7-101575).

FIG. 16 shows a schematic configuration of the air separation sheet feeding device.
The air separating and feeding apparatus shown in FIG. 16 sucks and conveys the stacked sheets P one by one, a tray 100 for stacking a plurality of sheets P, a blower 200 that blows air on the stacked sheets P, and the stacked sheets P. A suction belt 300 is provided. In order to supply paper with this air separation paper feeder, first, air is blown from the blower 200 toward a bundle of paper P stacked on the tray 100, and air is sent between the papers P by this air to feed the paper P. The suction belt 300 is lifted up to a height h. Then, the uppermost sheet P of the floated paper P is attracted to the suction belt 300, and the suction belt 300 rotates, whereby the paper P is conveyed to an image forming unit (not shown) and image formation is performed.

  16 is provided with an end fence 400 for positioning the rear end of the bundle of sheets stacked on the tray 100 in the conveyance direction. Thus, the paper P is prevented from being moved backward by the air blown from the blower 200, and the double feeding or non-feeding of the paper P is prevented.

  In addition, some of the end fences are configured to be movable in accordance with the paper size to be loaded. In this case, when the end fence is arranged with a margin with respect to the rear end of the paper, the back of the end fence 400 and the paper P is combined as shown in FIG. A gap S is formed between the ends. When air is blown from the blower 200 in this state, as shown in FIG. 17, the first sheet P <b> 1 in the uppermost position is retracted by the air and the second sheet P <b> 2 is sucked from the suction belt 300. Is attracted to the suction belt 300 under the influence of the above. As a result, a double feed occurs in which the first sheet P1 and the second sheet P2 are conveyed together.

  Further, if the sheets are stacked on the tray several times, the trailing ends of the sheets P may be stacked without being aligned as shown in FIG. In this case, even if the end fence 400 is disposed in contact with the rear end of the sheet bundle, a gap S is formed between the rear end of some sheets P and the end fence 400. In this state, when air is blown from the blower 200, the first sheet P1 at the uppermost position moves backward, and the second sheet P2 is sucked by the suction belt 300 and is double-feeded, as described above. Will occur.

  In the double feed in which two or more sheets are conveyed together as described above, not only white paper is mixed into the printed matter but also wasteful consumption of the sheets, so that the quality of the apparatus is remarkably deteriorated. .

  SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a recording medium supply apparatus capable of supplying a sheet-like recording medium such as paper in a good and stable manner while preventing double feeding, and an image forming apparatus including the recording medium supply apparatus. It is something to be offered.

According to a first aspect of the present invention, there is provided a stacking unit capable of stacking a plurality of sheet-like recording media, and air jetting means for blowing air onto the recording media stacked on the stacking unit to separate the recording media from each other. A recording medium supply comprising: a conveying unit that conveys the recording medium separated by the air ejecting unit one by one; and an end fence for positioning a rear end of the recording medium loaded in the stacking unit in the conveying direction. In the apparatus, the recording medium that is provided on the end fence so as to be able to protrude and house and presses the rear end in the transport direction of a plurality of recording media disposed on the transport unit side among the recording media stacked on the stacking unit. A pressing member having rigidity that is not deformed by the pressing, and an elastic member that urges the pressing member forward in the conveyance direction of the recording medium are provided .

Even if there is a gap between the end fence and the stacked recording medium, the rear end in the conveyance direction of the recording medium can be elastically pressed and positioned by the pressing member. Thereby, it is possible to prevent the recording medium from moving backward by the air ejected from the air ejecting means, and it is possible to prevent double feeding of the recording medium. In addition, since the pressing member can elastically press, the pressing member presses the recording medium with an appropriate pressing force even if the size of the gap between the rear end in the recording medium conveyance direction and the end fence changes. can do.
By the way, when a pressing member is used to press a wide range from the top to the middle layer of the stacked recording media, the pressing member may be rearward depending on the pressing force setting of the pressing member. Therefore, a gap may be generated between the rear end of the recording medium in the conveyance direction and the end fence. Therefore, as described in the present invention, the above-mentioned problem can be prevented by pressing the rear end in the transport direction of a plurality of recording media arranged on the transport means side among the stacked recording media. can do. Further, in this case, the arrangement position of the pressing member can be limited to a place necessary for preventing the double feeding of the recording medium, so that the compactness and the cost of parts can be reduced.

The invention of claim 2 is the recording medium supply apparatus according to claim 1 , wherein the recording medium supply apparatus is configured to stack the recording medium from above the stacking unit, and is provided above the pressing member. An inclined surface that is inclined downward toward the front in the conveyance direction of the recording medium is formed.

  By forming the inclined surface above the pressing member, when the recording medium is stacked on the stacking portion, the recording medium is lowered along the inclined surface (on the stacking portion of the stacking portion) without being caught by the upper portion of the pressing member. To the bottom). For this reason, it is possible to smoothly load the recording medium on the stacking unit.

According to a third aspect of the present invention, there is provided the recording medium supply device according to the first or second aspect , wherein when the recording medium stacked on the stacking unit decreases with the supply of the recording medium by the conveying means, the stacked medium is loaded. A recording medium supply device provided with a pushing-up means for raising the recording medium to a predetermined position, wherein an inclined surface is formed on the lower part of the pressing member, the surface being inclined upward in the recording medium conveyance direction. It is.

  In this case, the recording medium pushed up by the pushing-up means is moved forward in the transport direction along the inclined surface formed at the lower part of the pressing member. As described above, since the inclined surface is formed in the lower portion of the pressing member, it is possible to prevent the recording medium pushed up by the lifting means from being caught by the lower portion of the pressing member, and thus it is possible to prevent the recording medium from being unfed. In addition, since the recording medium disposed at a position retracted from the predetermined position can be moved forward in the transport direction by the inclined surface, occurrence of double feeding of the recording medium can be prevented.

According to a fourth aspect of the present invention, in the recording medium supply device according to any one of the first to third aspects, the pressing member can be accommodated in the end fence so as not to protrude.

  When the end fence is disposed so as to come into contact with the rear end in the conveyance direction of the recording medium, the pressing member is accommodated in the end fence so as not to protrude, so that the pressing member can be used when the recording medium is stacked. It is possible not to get in the way of loading work.

According to a fifth aspect of the present invention, in the recording medium supply device according to any one of the first to fourth aspects, the contact surface of the pressing member with the recording medium is formed of a smooth and highly wear-resistant material. It is a thing.

  If the pressing member is worn due to contact with the recording medium, the recording medium may be caught by the pressing member, and the recording medium may not be fed or the recording medium may be damaged. Therefore, it is possible to suppress wear of the pressing member by forming the contact surface of the pressing member with the recording medium with a material having high wear resistance. Furthermore, by forming the contact surface of the pressing member smoothly, it is possible to suppress the recording medium from being caught on the pressing member, and to prevent damage to the recording medium that has not been fed.

A sixth aspect of the present invention is an image forming apparatus comprising the recording medium supply device according to any one of the first to fifth aspects.

Since the image forming apparatus includes the recording medium supply device according to any one of claims 1 to 5 , the above-described effects of these recording medium supply devices can be obtained.

  According to the present invention, even if there is a gap between the end fence and the stacked recording medium, the rear end of the recording medium can be elastically pressed and positioned by the pressing member. Thereby, it is possible to prevent the recording medium from moving backward by the air ejected from the air ejecting means, and it is possible to prevent double feeding of the recording medium.

1 is an external view showing an embodiment of an image forming apparatus provided with a sheet feeding device of the present invention. 1 is a schematic configuration diagram of an image forming apparatus main body. 1 is a schematic configuration diagram of an entire sheet feeding device. It is a perspective view which shows the internal structure of a paper feeder. It is a perspective view which shows the internal structure of a paper feeder. It is a perspective view which shows the internal structure of a paper feeder. It is a schematic block diagram of the upper part of an end fence. It is a figure for demonstrating sheet feeding operation | movement. It is a figure for demonstrating sheet feeding operation | movement. It is a figure for demonstrating sheet feeding operation | movement. It is a figure for demonstrating sheet feeding operation | movement. FIG. 6 is a diagram illustrating a state where sheets are stacked on a sheet feeding tray without aligning the trailing ends of the sheets. It is a figure which shows the state arrange | positioned in contact with the rear end of the sheet | seat with which the end fence was loaded. FIG. 6 is a diagram illustrating a state in which stacked paper is pushed up. It is a figure which shows embodiment at the time of arrange | positioning a press member over the lower layer from the upper layer of a paper bundle. It is a schematic block diagram of the conventional air separation paper feeder. It is a figure for demonstrating the subject of the conventional air separation paper feeder. It is a figure for demonstrating the subject of the conventional air separation paper feeder.

  Hereinafter, the present invention will be described with reference to the accompanying drawings. In the drawings for explaining the present invention, components such as members and components having the same function or shape are denoted by the same reference numerals as much as possible, and once described, the description will be given. Omitted.

FIG. 1 is an external view showing an embodiment of an image forming apparatus provided with a sheet feeding device of the present invention.
As shown in FIG. 1, the image forming apparatus 1 includes an image forming apparatus main body 2 and a paper feeding device 3 connected to one side surface of the image forming apparatus main body 2.

FIG. 2 is a schematic configuration diagram of the image forming apparatus main body.
As shown in FIG. 2, the image forming apparatus main body 2 includes four process units 4Y, 4C, 4M, and 4Bk. Each process unit 4Y, 4C, 4M, 4Bk is configured to be detachable from the image forming apparatus main body 2. The process units 4Y, 4C, 4M, and 4Bk have the same configuration except that toners of different colors of yellow, cyan, magenta, and black corresponding to the color separation components of the color image are accommodated.

  Specifically, each of the process units 4Y, 4C, 4M, and 4Bk includes a photosensitive member 5 as an electrostatic latent image carrier, a charging roller 6 as a charging unit that charges the surface of the photosensitive member 5, and the photosensitive member 5. A developing device 7 as a developing means for forming a toner image on the surface of the photosensitive member 5 and a cleaning blade 8 as a cleaning means for cleaning the surface of the photoreceptor 5.

  In FIG. 1, an exposure device 9 as exposure means is disposed above each process unit 4Y, 4C, 4M, 4Bk. The exposure device 9 is configured to irradiate the photoconductor 5 of each process unit 4Y, 4C, 4M, 4Bk with laser light. On the other hand, a transfer device 10 is disposed below the process units 4Y, 4C, 4M, and 4Bk. The transfer device 10 includes an intermediate transfer belt 15 formed of an endless belt that is stretched around a plurality of rollers 11 to 14. The intermediate transfer belt 15 is configured to be able to run in the direction indicated by the arrow in the drawing when one of the rollers 11 to 14 rotates as a driving roller.

  Four primary transfer rollers 16 as primary transfer means are disposed at positions facing the four photoconductors 5. Each primary transfer roller 16 presses the inner peripheral surface of the intermediate transfer belt 15 at each position, and a primary transfer nip is formed at a place where the pressed portion of the intermediate transfer belt 15 and each photoconductor 5 are in contact with each other. ing. In addition, a secondary transfer roller 17 as a secondary transfer unit is disposed at a position facing one roller 14 that stretches the intermediate transfer belt 15. The secondary transfer roller 17 presses the outer peripheral surface of the intermediate transfer belt 15, and a secondary transfer nip is formed at a location where the secondary transfer roller 17 and the intermediate transfer belt 15 come into contact with each other.

  In the image forming apparatus main body 2, a conveyance path R for guiding the paper supplied from the paper feeding device 3 through the secondary transfer nip to a paper discharge tray 18 provided outside the apparatus is disposed. . In the transport path R, a registration roller 19 is disposed upstream of the position of the secondary transfer roller 17 in the paper transport direction. In addition, a fixing device 20 is disposed downstream of the position of the secondary transfer roller 17 in the sheet conveyance direction. Further, a pair of paper discharge rollers 21 are disposed on the downstream side of the fixing device 20 in the paper conveyance direction. The fixing device 20 includes a heating roller 20a having a heating source therein, and a pressure roller 20b that pressurizes the heating roller 20a. The heating roller 20a and the pressure roller 20b are in pressure contact with each other, and a fixing nip is formed at the pressure contact portion.

The basic operation of the image forming apparatus will be described below with reference to FIG.
The photoconductors 5 of the process units 4Y, 4C, 4M, and 4Bk are rotationally driven counterclockwise in the drawing, and the surface of each photoconductor 5 is uniformly charged to a predetermined polarity by the charging roller 6. Based on image information of a document read by a reading device (not shown), the surface of each photoconductor 5 charged from the exposure device 9 is irradiated with laser light, and an electrostatic latent image is formed on the surface of each photoconductor 5. Is done. At this time, the image information to be exposed on each photoconductor 5 is single-color image information obtained by separating a desired full-color image into color information of yellow, cyan, magenta, and black. As the toner is supplied to the electrostatic latent image formed on the photosensitive member 5 by each developing device 7 in this manner, the electrostatic latent image is visualized as a toner image.

  One of the rollers that stretch the intermediate transfer belt 15 is driven to rotate, causing the intermediate transfer belt 15 to run in the direction of the arrow in the figure. In addition, a constant voltage having a polarity opposite to the charging polarity of toner or a voltage controlled by a constant current is applied to each primary transfer roller 16, so that the primary transfer nip between each primary transfer roller 16 and each photoconductor 5. A transfer electric field is formed. Then, the toner images of the respective colors formed on the respective photoreceptors 5 are sequentially superimposed and transferred onto the intermediate transfer belt 15 by the transfer electric field formed in the primary transfer nip. Thus, the intermediate transfer belt 15 carries a full-color toner image on its surface. Further, the toner that could not be transferred to the intermediate transfer belt 15 remains on the surface of each photoconductor 5 after the transfer. The toner remaining on the photoreceptor 5 is removed by the cleaning blade 8.

  Further, the sheet is carried out from the sheet feeding device 3 shown in FIG. The unloaded paper is timed by a registration roller 19 and sent to a secondary transfer nip between the secondary transfer roller 17 and the intermediate transfer belt 15. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the intermediate transfer belt 15 is applied to the secondary transfer roller 17, and a transfer electric field is formed in the secondary transfer nip. Then, the toner image on the intermediate transfer belt 15 is collectively transferred onto the sheet by the transfer electric field formed in the secondary transfer nip.

  The sheet on which the toner image is transferred is conveyed to the fixing device 20. In the fixing device 20, the paper is sandwiched between the heating roller 20a and the pressure roller 20b and heated and pressurized, and the toner image is fixed on the paper. Thereafter, the paper is discharged to the paper discharge tray 18 by the pair of discharge rollers 21.

  The above description is an image forming operation when a full-color image is formed on a sheet. A single-color image is formed using any one of the four process units 4Y, 4C, 4M, and 4Bk. Alternatively, it is possible to form two-color or three-color images using three process units.

  Next, the paper feeding device of the present invention will be described with reference to FIGS.

FIG. 3 is a schematic configuration diagram of the entire sheet feeding device. 4, 5 and 6 are perspective views showing the internal structure of the paper feeding device.
A sheet feeding device 3 shown in FIG. 3 includes a sheet feeding tray 30 as a stacking unit on which a plurality of sheets P can be stacked, and a suction belt unit 40 having a suction belt 41 as a conveying unit that conveys the sheets P. ing. The paper P includes thick paper, postcard, envelope, plain paper, thin paper, coated paper (coated paper, art paper, etc.), tracing paper, and the like. The paper feeding device (recording medium supply device) according to the present invention is configured to be able to supply an OHP sheet or an OHP film as a sheet-like recording medium other than paper.

  As shown in FIG. 4, the paper feed tray 30 positions the bottom plate 31, the front fence 36 for positioning the front end of the sheet bundle stacked on the bottom plate 31 in the conveyance direction, and both ends of the sheet bundle in the width direction. A pair of side fences 32 and an end fence 33 for positioning the rear end of the sheet bundle in the transport direction.

  In FIG. 3, the suction belt 41 is disposed above the paper P stacked on the paper feed tray 30. The suction belt 41 is provided with a plurality of suction ports, and the sheet is sucked onto the lower surface of the suction belt 41 by air sucked from each suction port. Further, the suction belt 41 is stretched by a plurality of rollers, and when one of the rollers is driven to rotate, the suction belt 41 rotates in the direction of the arrow in the figure. In addition, a pair of transport rollers 50 that transport the paper P and a paper detection sensor 60 that detects the transported paper P are sequentially disposed downstream of the suction belt 41 in the paper transport direction.

  Above the paper feed tray 30, there is provided an upper surface position detection device 70 for detecting the position of the upper surface of the sheet bundle stacked on the paper feed tray 30. The upper surface position detection device 70 includes an actuator 71 configured to be in contact with the upper surface of the sheet bundle and swingable, and a swing detection sensor 72 that detects the swing of the actuator 71. The sheet is supplied from the sheet bundle, and the actuator 71 swings as the height of the sheet bundle decreases. Then, the swing detection sensor 72 detects the swing amount of the actuator 71, and the push-up means (not shown) raises the bottom plate 31 of the paper feed tray 30 based on the detection signal at that time, so that the top surface of the sheet bundle is lifted. The height h (distance) to the suction belt 41 is controlled to be constant.

  A blower 80 is provided in front of the sheet feeding direction of the sheet feeding tray 30 as air blowing means for blowing air onto the sheets P stacked on the sheet feeding tray 30. Further, a restricting member 34 is provided at the upper end portion of the front fence 36 of the paper feed tray 30 to restrict the movement of the sheets other than the uppermost sheet (second and subsequent sheets from the uppermost position) in the transport direction. . The restricting member 34 is disposed so as to protrude upward from the uppermost position of the sheet bundle loaded on the sheet feeding tray 30.

  As shown in FIG. 5, the blower 80 has a floating nozzle 81 that blows out air to float the paper, and an air to separate the uppermost sheet and the second and subsequent sheets below it. And a separation nozzle 82 for ejecting the gas. The separation nozzle 82 is disposed corresponding to the center portion in the sheet width direction, and the flying nozzle 81 is disposed corresponding to both end portions in the sheet width direction. In addition, the regulating member 34 is disposed at a position facing the separation nozzle 82.

  As shown in FIG. 3, a pressing member 35 that protrudes from the end fence 33 to the side of the stacked paper P is provided above the end fence 33. In the embodiment shown in FIG. 6, two pressing members 35 are provided, but the number of pressing members 35 may be one, or three or more.

FIG. 7 is a schematic configuration diagram of an upper portion of the end fence.
As shown in FIG. 7, the pressing member 35 is configured to be able to protrude and house with respect to the end fence 33. The pressing member 35 is urged to the left side of the drawing by a coil spring (not shown) provided in the end fence 33, so that the pressing member 35 is normally disposed in a state of protruding from the end fence 33. On the other hand, when a force against the urging force of the spring acts on the pressing member 35, the pressing member 35 is configured to be displaceable on the right side of the drawing. As a biasing means for biasing the pressing member 35, an elastic member such as a leaf spring, rubber, or sponge can be used in addition to the coil spring . Also, in this embodiment, the pressing member 35 is configured so as to be completely housed within the end fence 33 does not protrude. That is, when the pressing member 35 is completely accommodated in the end fence 33, the pressing surface 35a for pressing the paper of the pressing member 35 is the same as the contact surface 33a that can contact the paper of the end fence 33 from the protruding state. It is moved to the position (on the same plane).

  As shown in FIG. 7, the pressing member 35 has an inclined surface 35b formed at the upper portion and an inclined surface 35c formed at the lower portion. The inclined surface 35b formed at the upper portion is disposed so as to be inclined downward toward the front in the sheet conveying direction, and the inclined surface 35c formed at the lower portion is inclined upward toward the front in the sheet conveying direction. It is arranged like this.

Hereinafter, the paper feeding operation of the paper feeding device of the present invention will be described.
When a paper feed command is issued from the image forming apparatus main body, as shown in FIG. 8, air is blown from the blower 80 to the upper front side of the stacked paper stack. At the same time, air suction of the suction belt 41 is started. As a result, the first sheet P1 at the uppermost position of the stacked sheet bundle floats up to the height h of the suction belt 41 and is attracted to the lower surface of the suction belt 41.

  The air blown from the blower 80 includes air jetted from the levitation nozzle 81 and air jetted from the separation nozzle 82 shown in FIG. Specifically, first, air is ejected from the flying nozzle 81 toward both ends of the sheet, and the plurality of sheets positioned in the upper layer of the sheet bundle are floated while being separated from each other. In this state, when the suction by the suction belt 41 is started, the uppermost first sheet P1 is raised and sucked by the suction belt 41. Next, air is jetted from the separating nozzle 82 to the center of the sheet, and the second and subsequent sheets are pushed downward by the air. As a result, the first sheet P1 and the second sheet P2 are completely separated.

  Then, in a state where the first sheet P1 is attracted to the suction belt 41, as shown in FIG. 9, the rotation of the suction belt 41 and the transport roller 50 is started, and the first sheet P1 is transported. Thereafter, as shown in FIG. 10, when the first sheet P1 reaches the sheet detection sensor 60 and is detected, the rotation of the suction belt 41 is stopped. On the other hand, the transport roller 50 continues to transport the paper P1 with the suction belt 41 stopped. Then, as shown in FIG. 11, immediately after the first sheet P1 passes through the suction area of the suction belt 41, the second sheet P2 floats by the air blown from the blower 80 and is sucked by the suction belt 41. . Thereafter, the rotation of the suction belt 41 is resumed according to a preset paper feed interval, and the second sheet P2 is conveyed. Thereafter, the paper is sequentially supplied to the image forming apparatus main body by repeatedly performing the same paper feeding operation.

  Further, in the state shown in FIGS. 8 to 11, the end fence 33 is arranged with a margin with respect to the rear end in the conveyance direction of the stacked paper (hereinafter simply referred to as “rear end”). A gap S is generated between the rear end of the stacked paper P and the end fence 33. Thus, in the state where the gap S is generated between the end fence 33 and the rear end of the paper P, the rear end position of the paper P cannot be positioned by the end fence 33. However, in the present invention, since the pressing member 35 is provided on the end fence 33, it is possible to press the rear end of the sheet P in the upper layer of the sheet bundle by the pressing member 35. Thereby, it is possible to prevent the uppermost sheet P1 from being retracted by the air blown from the blower 80, and it is possible to prevent the sheets from being double-fed.

  FIG. 12 shows a state in which the trailing edge of the paper P is stacked on the paper feed tray 30 without being aligned. Also in this case, a gap S is generated between the rear end of the stacked paper P and the end fence 33, but the rear end of the paper P in the upper layer of the paper bundle is pressed by the pressing member 35 provided on the end fence 33. Is possible. Accordingly, similarly to the above, it is possible to prevent the uppermost sheet P1 from being retracted by the air blown from the blower 80, and it is possible to prevent the sheets from being double-fed.

The pressing member 35 elastically presses the rear end of the paper P by the urging force of an elastic member such as a coil spring. For this reason, even if the size of the gap S between the rear end of the paper P and the end fence 33 changes, the pressing member 35 presses the paper P with an appropriate pressing force by elastically deforming the elastic member. It is possible to prevent the sheet P from being excessively pressed .

  In the embodiment of the present invention, when the rear end of the uppermost sheet P1 is received by the inclined surface 35c (see FIG. 7) formed on the upper portion of the pressing member 35, the rear end of the sheet P1 extends along the inclined surface 35b. There is a risk of retreating. Therefore, in order to reliably prevent the uppermost sheet P1 from retreating, the pressing surface 35a extends to a position above the rear end of the uppermost sheet P1 in a state where air is blown and floated. It is necessary to arrange.

  FIG. 13 shows a state where the end fence 33 is in contact with the rear end of the stacked paper P. In this case, the pressing member 35 is accommodated in the end fence 33 so as not to protrude. As described above, when the end fence 33 is disposed so as to contact the rear end of the sheet P, the pressing member 35 is prevented from protruding from the end fence 33 so that the pressing member 35 can be used when the sheets are stacked. It does not get in the way of loading paper.

  In addition, since an inclined surface 35b is formed on the upper portion of the pressing member 35 so as to be inclined downward toward the front in the sheet conveyance direction (see FIG. 7), the pressing member is used when the sheets are stacked on the sheet feeding tray 30. Even when 35 protrudes, the sheet can be guided downward (the bottom plate 31 of the sheet feeding tray 30) along the inclined surface 35b. Thus, by forming the inclined surface 35b on the upper portion of the pressing member 35, the paper can be prevented from being caught on the upper portion of the pressing member 35, and the paper can be stacked smoothly.

  As shown in FIG. 14, when the number of stacked sheets decreases as the sheets are supplied, the upper surface detecting device 70 detects that the upper surface position of the sheet bundle is lowered, and pushes up (not shown) The means raises the bottom plate 31 of the paper feed tray 30. At this time, the sheet P to be pushed up is moved forward in the transport direction along the inclined surface 35 c formed at the lower part of the pressing member 35. In this way, by forming the inclined surface 35c at the lower portion of the pressing member 35, it is possible to prevent the pushed-up paper from being caught by the lower portion of the pressing member 35, and thus it is possible to prevent the occurrence of non-feed of the paper. Further, since the paper P disposed at a position retracted from the predetermined position can be moved forward in the transport direction by the inclined surface 35c, occurrence of double feeding of the paper can be prevented.

  Further, when the sheets are stacked or when the sheets are pushed up by the push-up means, the sheets are brought into sliding contact with the pressing member 35. As a result, when the pressing member 35 is worn, the paper is caught by the pressing member 35, and there is a possibility that the paper is not fed or the paper is damaged. For this reason, the contact surface of the pressing member 35 with the sheet (for example, the pressing surface 35a, the upper inclined surface 35b, and the lower inclined surface 35c shown in FIG. 7) is made of a material having high wear resistance. Wear of the member 35 can be suppressed. Furthermore, by forming the contact surface of the pressing member 35 smoothly, the paper can be prevented from being caught on the pressing member 35, and the non-feeding of the paper and the damage of the paper can be prevented.

  FIG. 15 shows a case where the pressing member 35 is disposed not only on the upper layer of the sheet bundle but also on the middle layer and the lower layer. In this case, if the rear end of the paper P is not aligned, depending on the setting of the pressing force of the pressing member 35, the pressing member 35 is maintained at the rear end position of the middle-layer paper P protruding backward, and is arranged on the upper layer. There may be a gap S between the rear end of the provided paper P and the pressing member 35. In this state, when air is ejected from the blower 80, the uppermost sheet P1 moves backward, so that the second sheet P2 is attracted to the suction belt 41, and double feeding of the sheets occurs. Also, if the pressing force of the pressing member 35 is increased and the middle layer and lower layer paper P is moved forward by the pressing member 35 so that the rear end positions of all the papers P are aligned, the problem of double feeding of the paper can be solved. However, when the pressing force of the pressing member 35 is increased, when the number of stacked sheets P decreases, the sheet P is pressed by the pressing member 35 and bent or curved, resulting in a conveyance failure. It is possible. As described above, when the pressing member 35 is disposed from the upper layer to the lower layer of the sheet bundle, there is a possibility that the above-described problems may occur.

  On the other hand, in the embodiment shown in FIG. 3, the pressing member 35 presses a plurality of sheets (from the topmost sheet to several sheets below) disposed in the upper layer of the sheet bundle on the suction belt 41 side. Therefore, it is possible to prevent the occurrence of the above-described problem caused by pressing the range from the upper layer to the middle layer or the lower layer of the sheet bundle. Further, in this case, the arrangement position of the pressing member 35 can be limited to a position necessary for preventing the double feeding of the paper, and there is an advantage that the size reduction and the cost reduction of parts can be achieved.

  The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention. In the above-described embodiment of the present invention, the configuration of the present invention is applied to a paper feeding device that blows air on a sheet bundle to separate the uppermost sheet from the lower sheet. The configuration of the present invention can also be applied to a paper feeding device (for example, a paper feeding device described in Japanese Patent Laid-Open No. 11-139600) that sprays and separates the lowermost paper and the paper above it. In addition, the paper feeding device (recording medium supply device) according to the present invention is not limited to the color image forming device shown in FIG. 1, but a monochrome image forming device, other copying machines, printers, facsimiles, or complex machines thereof. It can also be provided.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 3 Paper feeding apparatus (recording medium supply apparatus)
30 Paper tray (stacking section)
33 End fence 35 Press member 35a Press surface 35b Inclined surface 35c Inclined surface 41 Adsorption belt (conveying means)
80 Blower (Air jetting means)
P paper (recording medium)

Japanese Patent No. 4003073 JP-A-7-101575

Claims (6)

A stacking unit capable of stacking a plurality of sheet-like recording media, an air ejection unit for blowing air onto the recording medium stacked on the stacking unit to separate the recording media from each other, and the air ejection unit In a recording medium supply apparatus comprising transport means for transporting the separated recording media one by one and an end fence for positioning the rear end in the transport direction of the recording media stacked on the stacking unit,
The recording medium that is provided on the end fence so as to be able to protrude and house and presses the rear end in the transport direction of a plurality of recording media disposed on the transport means side among the recording media stacked on the stacking unit, and the pressing According to another aspect of the present invention, there is provided a recording medium supply apparatus comprising: a pressing member having rigidity that is not deformed depending on the recording medium; A recording medium supply device configured to stack a recording medium from above the stacking unit,
The recording medium supply apparatus according to claim 1, wherein an inclined surface that is inclined downward toward the front in the conveyance direction of the recording medium is formed on an upper portion of the pressing member . A recording medium supply device comprising a push-up means for raising the stacked recording medium to a predetermined position when the recording medium loaded on the stacking portion decreases as the recording medium is supplied by the conveying means. There,
The recording medium supply device according to claim 1, wherein an inclined surface that is inclined upward toward the front in the conveyance direction of the recording medium is formed at a lower portion of the pressing member . The recording medium supply apparatus according to any one of claims 1 to 3, wherein the pressing member is configured to be accommodated in the end fence so as not to protrude . The recording medium supply apparatus according to any one of claims 1 to 4, wherein a contact surface of the pressing member with the recording medium is formed of a smooth and highly wear-resistant material . An image forming apparatus comprising the recording medium supply device according to claim 1 .

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