JPH0986699A - Sheet feeder and image forming device provided with the sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeder capable of performing a sure sheet feed by eliminating generation of an improper paper feed regardless of sheet size, sheet kind (weighing amount, thickness) and presence of a curl on a sheet feed direction tip end side, without regulating the feed direction rear end of a sheet loaded on a sheet tray. SOLUTION: Of a plurality of sheets S loaded on a sheet tray 100, the sheet in the lowermost part is fed in a condition vacuum sucked by a feed belt 104 provided with a plurality of through holes. Here, a position on a width direction side-surface side of the sheet on the sheet tray 100 is regulated by regulating means 120, 121. In the sheet on the sheet tray 100, a flow of air from the one width direction side-surface side toward the other is injected from a nozzle 105. The sheet sucked to the feed belt 104 is separated from the other sheet by injection air from this nozzle 105.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an image forming apparatus such as a copying machine, a printer or a facsimile, and separates a plurality of sheets such as a plurality of originals or recording sheets stacked on a sheet stacking unit one by one. The present invention relates to a sheet feeding device for feeding.

[0002]

2. Description of the Related Art A recycle type automatic document feeder (RDH) for reading an image of a sheet-like document sent from a sheet stacking unit and returning the document to the top of the sheet on the sheet stacking unit again. An image forming apparatus such as a copying machine or other various printing devices and printing devices provided with the above-mentioned copying machine includes sheets of originals and recording sheets stacked on the sheet stacking unit.
A sheet feeding device that feeds the sheets located on the lowermost surface separately from other sheets one by one and feeds the sheets.

In such a sheet feeding apparatus, as means for separating sheets one by one, a separation method by air jetting, a separation method by a separation claw, a separation method by a roller rotating in the reverse direction to the sheet feeding direction, and the like are used. is there.

Among these, a sheet feeding apparatus adopting a separation method by air injection is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-27.
A "sheet feeding apparatus" disclosed in Japanese Patent No. 2932 is generally known. Also, as a configuration similar to this, U.S. Pat. No. 3,198,514 (corresponding Japanese application; Japanese Patent Publication No. 55-19857) is known.

FIG. 6 is a side view showing the structure of the conventional sheet feeding apparatus. Further, FIG. 7 is a plan view of a main part of the sheet feeding apparatus. Further, FIG. 8 is a perspective view of the support tray 3 as a sheet stacking unit on which the recording sheets 2 are stacked in this sheet feeding apparatus. As described above, the sheet feeding device shown in these figures has a configuration in which the recording papers 2 on the lowermost surface of the recording papers 2 stacked on the sheet stacking unit are separated and fed one by one. To be adopted.

The sheet feeding apparatus shown in these figures has a support tray (sheet stacking means) 3 on which recording sheets 2 are stacked.
It has. Then, on the support tray 3, there are provided a lateral regulating member (not shown) for regulating a side surface position (widthwise position) orthogonal to the feeding direction of the stacked recording papers 2, and a rear end position of the recording papers 2. A rear end regulating member 11 for regulating is provided. A cutout 4 is formed on the downstream side of the support tray 3 in the feeding direction of the recording paper 2 (arrow G side in FIG. 6) and near the center of the support tray 3 in the width direction.

As shown in FIG. 6, a pair of feed belts 7 having a large number of through holes are arranged below the support tray 3 so that the feed belts 7 are exposed from the cutouts 4. It is stretched around the rotating rollers 5 and 6.

An intake duct 8 facing the notch 4 via the feeding belt 7 is arranged between the rotating rollers 5 and 6. Then, the recording paper 2 on the support tray 3 is vacuum-sucked to the feeding belt 7 by its suction duct 8, and the recording paper 2 is moved in the feeding direction by the feeding belt 7 which is driven and driven by the rotating rollers 5 and 6. It is fed in the direction G in FIG. 6).

On the other hand, a plurality of recording papers 2 on the support tray 3 may be simultaneously adsorbed by the feeding belt 7, and the adsorbed plural sheets may be simultaneously fed by the feeding belt 7. . Therefore, as shown in FIG. 7, the air injection duct 9 is provided at a predetermined position above the support tray 3 on the downstream side in the feeding direction.
And a nozzle 10 parallel to the feeding direction (vertical direction in the drawing)
b to 10e and the plurality of nozzles 10a and 10f heading toward the center in the width direction are provided so as to communicate with each other. As shown in FIG. 8, the support tray 3 includes a base portion 14 extending from the downstream side to the upstream side in the feeding direction, and side blades formed diagonally upward from both widthwise side portions of the base portion 14. Parts 15 and 16.

The air injection duct 9 and the support tray 3 of this conventional example are arranged in a positional relationship as shown in FIG. 7, and the nozzles 10a to 10f generate a planar air flow near the center position of the support tray 3 in the width direction. I try to concentrate. The state of distribution of the air flow by the air injection duct 9 is as shown by the hatched portion in FIG.

[0011]

In such a conventional sheet feeding apparatus, air is jetted in the direction opposite to the feeding direction of the recording papers 2 stacked on the support tray 3, so that the loaded recording papers 2 are ejected. The rear end regulating member 11 that regulates the rear end position is essential (see FIG. 6). Therefore, different size recording paper 2
When the sheet is fed, the trailing edge regulating member 11 has to be moved according to the size of the recording paper 2, which makes the apparatus large and complicated.

Further, when a recording paper or an original having a curl (upper and lower) on the leading end side in the paper feeding direction is fed, an air flow caused by air jet hits the curl portion, which may cause separation failure or feeding failure. was there.

Further, when the recording paper 2 is fed in the longitudinal direction (longitudinal length of A3, B4 size), the air jetted from the air jet duct 9 does not reach the rear end portion of the recording paper 2 and is heavy. Sending is likely to occur. In order to prevent this double feed, it is conceivable to increase the wind pressure and air volume of the air flow of the air injection. However, when wind pressure and air volume increase,
The number of rotations of the blower for generating air flow increases,
It causes a problem that the noise becomes loud.

Therefore, according to the present invention, the sheet size or the type of sheet (basis weight, thickness), the sheet leading end side in the sheet feeding direction of the sheet stacked on the support tray is not regulated, and the trailing end in the sheet feeding direction is controlled. An object of the present invention is to provide a sheet feeding apparatus that can reliably feed a sheet without causing a paper feeding failure regardless of the presence or absence of curl, and an image forming apparatus including the sheet feeding apparatus.

[0015]

A sheet feeding apparatus according to the present invention includes a sheet stacking unit having a sheet stacking surface for stacking a plurality of sheets, and a direction orthogonal to a sheet feeding direction on the sheet stacking unit. Side regulating means for regulating the position of the sheet stacking means, feeding means for vacuum-sucking and conveying the lowermost sheet among the sheets stacked on the sheet stacking means, and a side surface side of the sheet on the sheet stacking means. Separation means for injecting air and separating the sheet vacuum-adsorbed by the feeding means from other sheets.

Further, in the sheet feeding apparatus of the present invention, the sheet stacking means is provided with a recess for guiding the air jetted from the separating means to the lower surface side of the sheets stacked on the sheet stacking surface. Is characterized by.

Further, in the sheet feeding apparatus of the present invention, the recess of the sheet stacking means is 2 mm to 5 mm with respect to the sheet stacking surface.
It is characterized in that a sloped surface that rises from the maximum depth of mm toward the downstream side in the sheet feeding direction is provided, and the end of the sloped surface is formed above the sheet stacking surface.

Further, in the sheet feeding device of the present invention, a cutout portion is formed on the slope, and the cutout is formed so that the portion of the feeding means for vacuum-sucking the sheet is substantially flush with the slope. It is characterized in that the feeding means is exposed from the section.

Further, in the sheet feeding device of the present invention, the side regulating means has a pair of side regulating members for regulating the position of the sheet in a direction orthogonal to the sheet feeding direction, and the pair of side regulating members. One of the side regulating members on the side facing the separating means includes a holding member that abuts on one side surface of the sheet to apply resistance, and the other side regulating member is a part of the other side surface of the sheet. It is characterized in that it is provided with a convex portion that abuts against.

Further, in the sheet feeding device of the present invention, the separating means injects air so as to cross the sheet feeding direction obliquely from the upstream side in the sheet feeding direction to the downstream side in the sheet feeding direction. It is characterized by doing.

Further, in the sheet feeding apparatus of the present invention, the separating means is located at a position 10 mm to 50 mm apart from the side end portion of the sheets stacked on the sheet stacking means and with respect to the sheet stacking surface. The air ejected at an angle of 30 to 60 degrees is arranged at a position where the air is introduced into the recess.

Further, the image forming apparatus of the present invention is provided with any one of the above-mentioned sheet feeding device and an image forming means for forming an image on a sheet fed from the sheet feeding device. I am trying.

(Operation) In the sheet feeding apparatus of the present invention, the sheets stacked on the sheet stacking means are held by the side regulating means, and the separating means ejects air toward one side surface of the sheet to feed the sheets. The lowermost sheet adsorbed by the means is separated from other sheets regardless of the type of sheet (size, basis weight, thickness), and the separated lowermost sheet is reliably fed by the feeding means.

Further, in the sheet feeding apparatus of the present invention, the air jetted from the separating means is guided to the lower surface side of the sheet by the concave portion, and the other sheets except the lowermost sheet adsorbed by the feeding means are floated, The bottom sheet and other sheets are easily separated.

Further, in the sheet feeding apparatus of the present invention, the end portion of the inclined surface forming the recess is located above the sheet stacking surface, imparts resistance to the sheet feeding direction to the sheet, and moves (takes out) the bundle of sheets. Block.

Further, in the sheet feeding apparatus of the present invention, the notch is formed on the slope forming the concave portion so that the sheet suction portion of the feeding means is substantially flush with the slope. The portion of the means for adsorbing the sheet is exposed from the cutout portion, and the feeding means reliably adsorbs and feeds the sheet on the lowermost surface.

Further, in the sheet feeding device of the present invention, the holding member provided on one side regulating member on the side facing the separating means is brought into contact with one side surface of the sheet, and the air jetted from the separating means is used. The sheet bundle is prevented from moving in the feeding direction. Further, the convex portion provided on the other side regulating member is brought into contact with the other side surface of the sheet to turn up the side surface of the sheet, and the air jetted from the separating means easily flows between the sheets.

Further, the sheet feeding device of the present invention ejects air from the separating means so as to cross the sheet feeding direction obliquely from the upstream side in the sheet feeding direction to the downstream side in the sheet feeding direction. Therefore, air is sent to the leading end side of the sheet in the feeding direction, and the lowermost sheet adsorbed by the feeding means and the leading end side of other sheets are easily separated.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment of the Invention) FIG. 1 is a perspective view of a sheet feeding apparatus 110 showing a first embodiment of the present invention.
Further, FIG. 2 is a side sectional view of the sheet feeding apparatus 110. 3 is a front view of the sheet feeding device 110 (a front view seen from the right direction (paper feeding direction) in FIG. 2). Further, FIG. 4 is a plan view of the sheet feeding device 110.

In these figures, the sheet feeding device 11
0 is a sheet tray (sheet stacking unit) 100 on which the sheets S are stacked, and is arranged on the upstream side of the lower surface of the sheet tray 100 in the feeding direction, and the lowermost sheet S of the stacked sheets S is arranged.
A sheet feeding means 101 for adsorbing and conveying 1 and a sheet tray 10.
Nozzles (separating means) 105 for injecting air toward the width direction (direction orthogonal to the feeding direction) side end surface of the sheet S stacked on 0, and the width direction side end surface (side surface) of the stacked sheets S
And a pair of side regulating members 120 and 121 as side regulating means for regulating the.

The feeding means 101 includes a plurality of rotating rollers 103a, 103b, 103 on the lower surface side of the sheet tray 100.
c is arranged, and the rotating rollers 103a, 103b, 10
A feeding belt 104 having a large number of through holes is stretched around 3c. Then, the rotating rollers 103a and 103
An intake duct 102 having an opening that opens upward in FIG. 2 is arranged in the space between b. The intake duct 102 vacuum-adsorbs the lowermost sheet S1 of the sheets stacked on the sheet tray 100 through a large number of through holes of the feeding belt 104. As a result, the sheet vacuum-adsorbed on the feeding belt 104 is fed and conveyed by the rotational driving of the rotating roller 103a.
The rotating roller 103a is connected to a driving means such as a motor (not shown). Further, the intake duct 102 is connected to a compressor or the like (not shown).

The sheet tray 100 has a sheet stacking surface 100c on which sheets S are stacked and an inclined surface 100a inclined downward in FIG. 2 from an end of the sheet stacking surface 100c in the sheet feeding direction.
And from the lowermost end of the slope 100a to the downstream side in the feeding direction (see FIG.
It is configured with a slope 100b that rises toward the middle right side). It should be noted that it is desirable that the tip of the slope 100b (the right end in FIG. 2) be higher than the horizontal plane of the sheet tray stacking surface 100c.

The purpose of making the tip of the above-mentioned slope 100b higher than the sheet stacking surface 100c is to feed the lowermost sheet S1 while the lowermost sheet S1 is being fed and to feed the lowermost sheet S1. Is to prevent the sheet from moving downstream in the feeding direction. That is, the stacked sheets S
Is to prevent the sheet tray slope 100b from moving downstream in the feeding direction.

The sheet tray 100 has a slope 10
0a and the slope 100b, the recess 100 _{1 on the} sheet stacking surface.
Is formed. The recess 100 ₁ maximum deep part 2mm~5mm lowered with respect to the sheet stacking surface 100c (FIG. 2
It is formed so as to be positioned in the middle lower part), thereby stabilizing the sheet separating and feeding operations.

Here, the maximum depth of the recess 100 ₁ means the intersection of the slope 100a and the slope 100b. Further, the stable separation and feeding operation of the sheets means that the lowermost sheet S1 of the stacked sheets S is peeled off from the other stacked sheets S when the lowermost sheet S1 of the stacked sheets S is attracted by the feeding means 101, and the peeling is performed. The lowermost sheet S1 thus formed is the sheet tray 1
00 to be closely attached to the concave portion 100 ₁ formed on the stack sheet S
And a space is formed between the lowermost sheet S1. When air is ejected from the nozzles 105 toward this space, the stacked sheets S float, and the friction between the stacked sheets S and the lowermost sheet S1 is reduced, so that the lowermost sheet S1 can be easily fed and conveyed. can do.

Further, the slope 100b upstream of the sheet tray 100 in the feeding direction is provided with a cutout portion 100d which faces (exposes) the feeding belt 104 of the feeding means 101 described above. The relationship between the slope 100b of the sheet tray 100 and the feeding belt 104 is that the feeding belt 104 has the slope 100b.
It is preferable that the feeding belt 104 is parallel to b and is at least substantially on the same plane as the inclined surface 100b (preferably, it is projected from the same plane to about 2 mm).

Further, as shown in FIG. 2, the feeding belt 104 is wound around the rotating rollers 103a, 103b, 103c in a substantially "V" shape so that the right end portion of the feeding belt 104 is closer to the tip end side of the slope 100b. Is also located below and functions to form a separated space between the front end surface (the right end in FIG. 2) of the stacked sheets S and the lowermost surface sheet S1. By exhausting the air jetted from the nozzle 105, this space exerts a rectifying effect on the air and prevents flapping of the sheet due to the blown air.

Furthermore, the positional relationship between the feeding belt 104 and the side end surface of the sheet S is as shown in FIG.
On the side where the is arranged (the left side in FIG. 3), the distance l from the side end surface of the sheet S to the side edge of the feeding belt 104 is 3 m.
It is desirable to set it to m to 10 mm. This feeding belt 10
4 and the side end surface of the sheet S are the lowermost sheet S
When 1 is adsorbed on the feeding belt 104, the nozzle 105
The range in which the sheet S1 does not flap due to the air jetted from

Next, the side regulating means provided on the sheet tray 100 will be described.

The side regulating member 121 as the side regulating means is provided at a position facing the air injection nozzle 105.
The side edges of the stacked sheets S are regulated. A holding member 123 that holds the stacked sheets is provided substantially at the center of the side regulating member 121. The holding member 123 is made of, for example, an elastic member such as a sponge, and presses the side end surface of the stacked sheets S to apply resistance, thereby preventing movement of the sheets S in a bundle in the feeding direction, double feeding, and removal. To do. In addition, the side regulating member 121, depending on the sheet size to be fed,
It is attached to the sheet tray 100 so that the position of the sheet in the width direction (direction orthogonal to the sheet feeding direction) can be adjusted.

On the other hand, the side regulating member 120 as a side regulating means located on the air injection nozzle 105 side is provided with a convex portion 124 which is fixed at a predetermined position on the tray 100 and abuts against a part of the stacked sheets S. There is. The convex portion 124 is
For example, a rib-shaped member punched from the side regulating member 120 may be used. The convex portions 124 are provided so as to lift up the side edges of the stacked sheets S and to facilitate the air flow from the air injection nozzle 105 to enter the lower surface side of each rolled up sheet S.

Next, the air injection nozzle 105 will be described with reference to FIGS.

The air injection nozzle 105 has a predetermined distance (10 mm to 50 mm) from the side end (the left end in the drawing) of the stacked sheets S.
mm) away from each other, an air injection opening is provided. As shown in FIG. 3, the air injection nozzle 105 has an angle θ (3
(0 ° -60 °), the jetted airflow is blown onto the surface of the sheet tray 100 as indicated by an arrow in the figure, and then the blown airflow is fed to the sheet S.
It goes to the side edge of. Therefore, the rectified airflow hits the stacked sheets S, and the sheets S are reliably separated one by one.

Further, as shown in FIG. 4, the air jet nozzle 105 has the air flow jet opening portion (the direction of the jetted air stream) from the upstream side of the sheet feeding direction with respect to the sheet feeding direction. It is arranged at an angle α so as to cross diagonally toward the downstream side in the direction. In this way, by inclining the nozzle 105 by the angle α, the airflow ejected from the nozzle 105 flows from the central portion of the sheet feeding apparatus 110 to the downstream side in the feeding direction. Therefore, it is possible to prevent the sheets S stacked on the sheet tray 100 from locally lifting and also to prevent the sheets S from flapping.
It is possible to reliably separate and feed sheets. (Image Forming Apparatus) Next, an image forming apparatus (copier) including the above-described sheet feeding apparatus 110 of the present invention will be described with reference to the sectional view of FIG.

As shown in the figure, the image forming apparatus main body 200 is provided with a document placing table 206, a light source 207, an optical system 208, a sheet feeding section 209, an image forming section (image forming means) 202 and the like. The paper feed unit 209 includes a paper feed tray 210, a cassette 211, and a paper deck 213.
The image forming unit 202 includes a photoconductor 214, a developing device 215 containing toner, a transfer charger 216, and a separation charger 21.
7, a cleaner 218, a primary charger 219, etc. are arranged respectively. Downstream of the image forming unit 202, a conveying unit 220, a fixing device 204, a discharge roller 205, and the like are provided.

In this image forming apparatus, when a sheet feeding signal is output from a controller (not shown) provided in the apparatus main body 200, the sheet S is fed from the sheet feeding tray 210, the cassette 211 or the paper deck 213. It On the other hand, the light radiated from the light source 207 to the original placed on the original placing table 206 and reflected is condensed on the photoconductor 214 via the optical system 208. The photoconductor 214 is charged in advance by a primary charger 219, and an electrostatic latent image is formed by light reflected from a document, and then a toner image is formed by a developing device 215.

The sheet S fed from the paper feeding unit 209 is
The skew feeding is corrected by the registration roller 201, and the timing is adjusted to be sent to the image forming unit 202. In the image forming unit 202, the transfer charger 216 transfers the toner image on the photoconductor 214 to the sent sheet S, and the transferred sheet S is separated from the transfer charger 216 by the separation charger 217. Photosensitive member 2 charged with polarity
Separated from 14.

Then, the separated sheet is conveyed by the conveying device 2
The sheet 20 is conveyed to the fixing device 204, and the fixing device 204 permanently fixes the unfixed transferred image. The sheet S on which the image has been fixed is discharged out of the apparatus main body 200 by the discharge roller 205.

On the other hand, in the case of double-sided copying or multiplex copying, the sheet copied on one side is discharged in the direction of arrow F on the sheet tray 100 of the sheet feeding device 110 according to the above-described embodiment. Then, the sheet tray 100
As described above, the sheets stacked on the sheet are reliably separated one by one from the lowest sheet, re-fed, and sent from the registration roller 201 to the image forming unit 202 to be copied again. . As a result, first, the paper feeding unit 209
The sheet S fed from is subjected to double-sided copying or multiple copying and is discharged to the outside of the apparatus main body 200. (Other Embodiments) The present invention is not limited to the above embodiment, and may be applied to, for example, an automatic document feeder (ADF) for automatically feeding a document.

As this automatic document feeder, for example, as shown in FIG. 5, a document tray 3 on which a document is placed is placed.
00, a sheet feeding device 301 to which the present invention is applied,
A transport belt 302 for transporting the document sent from the document tray 300 by the sheet feeding device 301 by sandwiching the document between the document placing table 206, a light source 207, and an optical system 2;
There is one that is roughly configured by a discharge tray 303 for stacking a document whose image is read by a document reading unit configured by 08 and the like.

[0051]

As described above, in the sheet feeding device of the present invention, the sheets stacked on the sheet stacking means are held by the side regulating means, and the separating means injects air toward one side surface of the sheet. The sheet (size,
It is possible to separate the sheet on the lowermost surface by the sheet feeding means without fail, regardless of the type, and it is not necessary to provide a member for regulating the rear end position of the sheet. It is possible to effectively prevent downsizing and complication of the device.
Further, in the sheet feeding device of the present invention, the separating means injects air toward one side surface of the sheet to separate the lowermost sheet adsorbed by the feeding means from other sheets. Therefore, even if the leading edge of the sheet is deformed such as curl, the lowermost sheet can be reliably separated from the other sheets, and the double feeding of the sheets can be effectively prevented. Further, in the sheet feeding apparatus of the present invention, the separating means injects air toward the one side surface of the sheet to surely separate the lowermost sheet adsorbed by the feeding means from other sheets. Therefore, it is not necessary to increase and change the air pressure and the air volume of the separating means according to the stacking amount of sheets, and it is possible to prevent the generation of noise due to the increase in the capacity of the separating means and to improve the quietness of the apparatus.

Further, in the sheet feeding apparatus of the present invention, the air jetted from the separating means is guided to the lower surface side of the sheet by the concave portion, and the other sheets except the lowermost sheet adsorbed by the feeding means are floated, Since it is possible to easily separate the lowermost sheet from other sheets, it is possible to more effectively prevent defective feeding such as double feeding of the sheets.

Further, in the sheet feeding apparatus of the present invention, the end portion of the slope forming the concave portion is located above the sheet stacking surface, imparts resistance to the sheet feeding direction to the sheet, and moves (takes out) the sheet bundle. Since it is possible to prevent it, it is possible to more effectively prevent the seat from being taken out.

Further, in the sheet feeding apparatus of the present invention, the notch is formed on the slope forming the concave portion, and the sheet is adsorbed so that the sheet suction portion of the feeding means is substantially flush with the slope. The sheet adsorbing portion of the means is exposed from the cutout portion, and the feeding means can surely adsorb and feed the lowermost sheet, so that the reliability of the apparatus can be significantly improved. .

Further, in the sheet feeding apparatus of the present invention, the holding member provided on one side regulating member on the side facing the separating means is brought into contact with one side surface of the sheet, and the air jetted from the separating means is used. The sheet bundle is prevented from moving in the feeding direction. Further, the convex portion provided on the other side regulating member is brought into contact with the other side surface of the sheet to turn up the side surface of the sheet, and the air jetted from the separating means easily flows between the sheets. Therefore, according to the sheet feeding apparatus of the present invention, the separating performance of the sheet is further improved, and the effect of preventing the sheet from being taken out can be increased.

Further, the sheet feeding apparatus of the present invention ejects air from the separating means so as to cross the sheet feeding direction from the upstream side in the sheet feeding direction to the downstream side in the sheet feeding direction obliquely. Therefore, air can be sent to the leading end side of the sheet in the feeding direction, and the separation of the lowermost sheet adsorbed by the feeding means and the leading end side of other sheets can be facilitated, so that the separating performance of the sheet is improved, It is possible to more effectively prevent defective feeding such as double feeding of sheets.

Further, since the image forming apparatus of the present invention is equipped with the sheet feeding apparatus as described above, the image can be surely formed on the sheet, and the reliability of the image forming apparatus is remarkably improved. The image forming apparatus can be downsized, and the quietness can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a side sectional side view of the sheet feeding device.

FIG. 3 is a front view (front view) of the sheet feeding device.

FIG. 4 is a plan view (top view) of the sheet feeding device.

FIG. 5 is a cross-sectional view of an image forming apparatus including a sheet feeding device according to the present invention.

FIG. 6 is a side sectional view of a conventional sheet feeding device.

FIG. 7 is a plan view (top view) of a main part of a conventional sheet feeding device.

FIG. 8 is a perspective view of a tray in a conventional sheet feeding device.

FIG. 9 is an explanatory diagram of air flow distribution in the conventional sheet feeding apparatus.

[Explanation of symbols]

100 Sheet Tray (Sheet Stacking Means) 100b Slope 100c Sheet Stacking Surface 100d Cutouts 100 ₁ Recesses 101 Feeding Means 105 Nozzles (Separating Means) 110 Sheet Feeding Devices 120 Side Restricting Members (Side Restricting Means) 121 Side Restricting Members ( Side regulating means) 123 holding member 124 regulating member 202 image forming portion (image forming means) S sheet S1 lowermost sheet

Claims (8)

[Claims] 1. A sheet stacking means having a sheet stacking surface for stacking a plurality of sheets, a side restricting means for restricting a position of the sheet stacking means in a direction orthogonal to a sheet feeding direction, and the sheet stacking means. A sheet feeding means for vacuum-adsorbing and transporting the lowermost sheet among the sheets stacked on the sheet stacking means, and air is jetted to the side surface side of the sheet on the sheet stacking means so that the sheet is vacuum sucked up A sheet feeding device, comprising: a separating unit that separates the separated sheet from other sheets. 2. The sheet stacking means is formed with a recess for guiding the air jetted from the separating means to the lower surface side of the sheets stacked on the sheet stacking surface. Sheet feeding device. 3. The recess of the sheet stacking means is provided with a slope that rises from a maximum depth of 2 mm to 5 mm with respect to the sheet stacking surface toward the downstream side in the sheet feeding direction, and the end of the slope is the sheet stacking surface. The sheet feeding device according to claim 2, wherein the sheet feeding device is formed so as to be positioned above the sheet feeding device. 4. A notch is formed in the slope, and the feeder is exposed from the notch so that the portion of the feeder that vacuum-sucks the sheet is substantially flush with the slope. The sheet feeding device according to claim 3, wherein 5. The side regulating means has a pair of side regulating members for regulating the position of the sheet in a direction orthogonal to the sheet feeding direction, and faces the separating means of the pair of side regulating members. One side regulating member on one side includes a holding member that abuts on one side surface of the sheet to apply resistance, and the other side regulating member includes a convex portion that abuts on a part of the other side surface of the sheet. The sheet feeding device according to claim 1. 6. The separating device injects air so as to traverse obliquely from the upstream side of the sheet feeding direction toward the downstream side of the sheet feeding direction with respect to the sheet feeding direction. The sheet feeding device described. 7. The separating means is located at a position separated by 10 mm to 50 mm from a side end portion of the sheets stacked on the sheet stacking means, and at an angle of 30 degrees to 60 degrees with respect to the sheet stacking surface. The sheet feeding device according to claim 1, wherein the jetted air is arranged at a position where the air is introduced into the recess. 8. The method according to claim 1, wherein
An image forming apparatus, comprising: the sheet feeding device according to the item 1; and an image forming unit that forms an image on a sheet fed from the sheet feeding device.