JPH1120958A - Sheet feeding device and picture image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separately feed sheets without failure by providing a guide, which guides a plurality of stacked sheets to a separation feeding means by gradually sliding the sheet ends sheet by sheet towards the feeding direction, in the upstream of the separation feeding means. SOLUTION: A guide for guiding a plurality of sheets to a separation feeding means by sliding the sheet ends sheet by sheet towards the feeding direction is composed by providing a feeding guide surface 201 for guiding sheets being fed by a feeding roller 101 and a separation pad 102, which are the separation feeding means, a conveyance guide surface 104 for sheets to be conveyed from a sheet stack, and a bent surface 202 for guiding sheets by respectively connecting smoothy the feeding guide surfaces 201, 204. The guide is arranged in the upstream of the separation feeding means. Thus sheets can be separately fed without failure and without the separation feeding means shouldering a burden.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus for reading an image of a document or forming an image on a sheet, such as an image scanner, a copying machine, a printer, or a facsimile apparatus. The present invention relates to a sheet feeding device provided in these devices for feeding a sheet.

[0002]

2. Description of the Related Art Conventionally, as this type of image processing apparatus, there are, for example, an image scanner, a copying machine, a printer, and a facsimile apparatus.

An image scanner is provided with a reading device for reading a document image, and is a device for sending read image information to a computer, a printer, or the like.

A copying machine has functions of an image forming apparatus and an image reading apparatus, and generally has a function of reading an image of a document or the like, and forms an image on a sheet based on the read image information. In recent years, however, there has been a copying machine having a communication function or the like and a function of inputting image information sent from the outside.

A printer has a function as an image forming apparatus, and generally forms an image on a sheet based on image information sent from an external device such as a computer. .

[0006] The facsimile apparatus has functions as an image forming apparatus and an image reading apparatus, and generally has a function of reading an image of an original or the like and a communication function, and sends read image information to the outside. Also, an image is formed on a sheet based on information sent from outside.

These image processing apparatuses are provided with a sheet feeding device for feeding a sheet to an image reading unit or for feeding a sheet to an image forming unit.

Hereinafter, these image processing apparatuses will be described with reference to FIG.
This will be briefly described with reference to FIG.

FIG. 10 is a schematic perspective view of the configuration of the image processing apparatus.

[0010] As shown in the figure, the image processing apparatus is provided with regulating members 601 and 602 for regulating the position in the width direction in accordance with the size of the sheet width, and for stacking the sheets.
And plate-like member 60 for guiding sheet conveyance
A plurality of sheet materials (hereinafter, abbreviated as paper or paper bundles as a general name as needed) S are set in a sheet material placing means (hereinafter, abbreviated as a paper feed tray) composed of 3,606, and fed. Aircraft 6 one by one from paper slot 604 in the direction of arrow A
07, performs predetermined image processing (image reading, image formation, and the like), and sequentially discharges paper in the direction of arrow B from the paper discharge port 605.

Next, the image processing apparatus according to the prior art, in particular, the feeding will be described with reference to FIG.

FIG. 11 is a schematic sectional view of a conventional image processing apparatus.

In FIG. 11, reference numerals 706 and 707 denote constituent members of a paper feed tray. Reference numeral 701 denotes a paper separating mechanism (hereinafter, abbreviated as a separating pad) which constitutes a friction type separating / feeding unit. A member 703 is a pressure spring that urges the separation pad 702 toward the feeding roller 704.

Reference numeral 709 denotes a stopper for adjusting the position of the leading end of the paper when setting the paper.

Reference numeral 705 denotes an image processing unit for performing predetermined image processing (image reading and image formation). The sheet bundle S set in the apparatus is separated one by one into the image processing unit 705 by a feed roller 704 and a separation pad 701. After being fed and subjected to predetermined image processing, it is discharged out of the machine from the paper discharge port 708.

As described above, in the prior art, the separation of the paper bundle is performed only by the friction member of the separation pad, and the conditions such as the pressure of the separation pad, the contact angle with respect to the paper transport direction, and the hardness of the roller are determined. Had been optimized.

[0017]

However, in the case of the above-described prior art, the following problems have occurred.

As described above, in the prior art, the paper separating function all depends only on the pressing force and friction characteristics of the separating pad.

In such a case, particularly when the sheet is conveyed in the vertical direction as in the configuration shown in FIG. 7 (when the sheet is conveyed along the conveying path by its own weight).
, It is necessary to separate the sheets one by one after supporting the weight of the paper bundle S with the separation pad 701. For this reason, the separation pad 701 loses the weight of the paper bundle S and separates from the feeding roller 704. When the paper bundle S at the time of paper feeding flows into the separation pad 701, it becomes extremely difficult to normally separate the paper, and the weight per unit area of the paper increases depending on the type of paper (sheet). However, there has been a problem that image processing cannot be performed at all due to frequent double feeding.

On the other hand, it is often practiced to increase the urging force of the separation pad 702, but in such a case, the urging force of the separation pad 702 is reduced by the image processing unit. Since it acts as a reaction force (back tension) with respect to the paper conveyance force of 705, the image after image processing may be extended to a level that is not practically acceptable.

On the other hand, the image processing unit 705
Roller 7 of the image processing unit 705 to increase the conveying force of
In some cases, the pressure is increased by increasing the pressing force of the pressure plate 11, but in this case, the rigidity of the device structure itself is increased so as not to stay around the separation pad 701 so as to withstand a large acting force. It was necessary, and the device was oversized.

Further, it is necessary to increase the operation force of each part of the mechanism more than necessary, and the practical operability has been seriously reduced.

On the other hand, in order to avoid these problems, it has been practiced to limit the number of stacked paper bundles in advance and to limit the types of paper (sheets) that can be handled. It was not always satisfactory for the users who used it in the field.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a highly reliable sheet feeding apparatus capable of reliably separating and feeding sheets with a simple configuration. An object of the present invention is to provide a feeding device and an image processing device.

[0025]

In order to achieve the above object, in a sheet feeding apparatus according to the present invention, a stacking section for stacking a plurality of sheets, and a sheet stacked on the stacking section are arranged one by one. In a sheet feeding apparatus having separation feeding means for separating and feeding, a guide for guiding the leading end of a plurality of stacked sheets to the separation feeding means by gradually shifting the leading end of the stacked sheets one by one in the feeding direction is provided. It is characterized by being provided on the upstream side of the separation feeding means.

Therefore, the sheet is separated and fed one by one by the separating and feeding means after the leading edge of the sheet is gradually shifted by the guide and fed, so that the sheet can be separated and fed with a simple configuration.

[0027] It is preferable that the separating and feeding means has a roller and a friction member biased in the direction of the roller.

Further, the separating and feeding means includes a friction member,
And a roller having a flexible surface arranged so as to be in contact with the surface of the friction member.

It is preferable that a pressing means for pressing the leading end of the sheet be provided on the surface of the roller on the upstream side of the separating section by the separating and feeding means.

Therefore, since the leading end of the sheet is pressed by the pressing means, even the curled sheet is reliably fed by the rollers.

The pressing means is preferably a thin plate having flexibility.

The sheets stacked on the stacking section are preferably conveyed by their own weight along a conveying surface.

The guide intersects a conveying guide surface including a conveying surface of the sheet conveyed from the stacking portion at an obtuse angle with respect to the conveying guide surface, and the guide of the sheet fed by the separation feeding means is provided. And a feeding guide surface portion substantially parallel to the feeding surface.

Accordingly, the plurality of sheets conveyed on the conveyance guide surface portion are abutted by the feeding guide surface portion, and the leading ends of the sheets are gradually shifted one by one from the surface side in the feeding direction.

The guide may include a bent surface connecting the transport guide surface and the feed guide surface.

Therefore, the sheet conveyed by the conveying guide surface is smoothly guided to the feeding guide surface by the bent surface portion while shifting one by one.

It is preferable that a part of the surface of the friction member protrudes from the conveyance guide surface.

[0038] The bent surface portion may be arranged on an upstream side of a separating portion by the separating and feeding means.

In order to achieve the above object, the image processing apparatus of the present invention is preferably provided with reading means for reading a document image of a document sheet conveyed by the sheet feeding device.

Further, an image forming means for forming an image on a sheet conveyed by the above-mentioned sheet feeding apparatus may be provided.

[0041]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) A sheet feeding apparatus and an image processing apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic front view of a main part of a sheet feeding apparatus according to a first embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1 ((a) is an AA section in FIG. 1). Figure, (b)
Is a cross-sectional view taken along the line BB in FIG. 1).

FIG. 3 is a schematic configuration diagram of an image processing apparatus provided with a sheet feeding device according to the first embodiment of the present invention, and FIG. 4 is a diagram illustrating the image processing device according to the first embodiment of the present invention. FIG. 4 is an operation explanatory diagram illustrating an operation in the sheet feeding device.

The configuration and the like of the entire image processing apparatus are the same as those of the above-described prior art, so a detailed description thereof will be omitted, and the features of the present embodiment will be described in detail below.

That is, in the prior art, the sheets stacked on the stacking unit are transported as they are to the separating and feeding means and separated and fed, but in the present embodiment, the sheets stacked on the stacking unit are After performing a predetermined process, the sheet is conveyed to the separation feeding unit.

Hereinafter, the processing will be described with reference to FIG.

The feature of the present embodiment resides in that an operation of manually separating paper (sheet) by a person is applied.

That is, similar to the operation in which a person manually separates paper in the paper feed conveyance path in the image processing apparatus, before the paper is separated by the separation pad, the leading edge of the paper is separated and the separation paper is sequentially moved from the top paper. Various types of paper (sheets) with different thicknesses, sizes, and surface properties by reducing the load on the separation function of the separation pad by providing a paper transport surface shape that fits
This ensures that separation can be performed.

An example of the operation when a person separates and removes a sheet bundle one by one by hand will be described with reference to FIG.

As shown in the figure, the operation of separating the paper by hand by a person is as follows. First, the placed paper bundle is lifted by a certain angle θ from the placed surface so that the leading end of the paper to be taken out comes first. (The uppermost sheet in the example), bend the tip of the sheet bundle a little with a fingertip and cut the tip.

Next, the paper to be taken out and the paper under it are squeezed by the frictional force of the finger as shown by arrows D and E in the figure.

As described above, it can be seen that there are two basic operations in the operation of separating paper manually by a person, first of all, separating the paper, and then separating the paper (friction separation).

FIG. 4B is a model diagram in which this series of motions is replaced by machine motions.

In this figure, the angle θ ₁ corresponds to the same angle θ required for separating the leading end of the paper in FIG. 4A, and the feed roller 101 and the separation pad 102 are fingers for separating the paper. It corresponds to.

That is, in the actual mechanism design, as shown in the figure, the transport guide surface 1 on the upstream side of the feed roller 101 is used.
04 is tilted above the separation pad by a certain angle θ _1, and an extension of the direction of the conveyance guide surface 104 toward the separation pad 102 and an extension of the feed guide surface downstream of the separation pad 102 or a parallel line thereof. Is provided, and the leading end portion of the sheet bundle S is pre-filtered, and then the sheet enters the separation pad 102 in order from the top sheet. What is necessary is just to depend on the pat 102.

The transport guide surface 104 and the feed guide surface may be connected by a curved surface with the above-mentioned bending point P as the vertex.

In the case of cardboard or the like, it is known from past experience that the degree of dependence is different, but separation can be performed only by the operation of separating the leading end without necessarily relying on the separation pad.

Next, a sheet feeding apparatus and an image processing apparatus to which the above mechanism is applied will be described with reference to FIGS.

In the present embodiment, a description will be given of an image scanner which performs an image reading process by a contact image sensor system as an example of an image processing apparatus.

In FIG. 1, 101 is a feed roller, 1
Reference numeral 02 denotes a separation pad provided with a friction member, which constitutes a part of a separation pad unit including a pressure urging mechanism and the like, and these constitute a separation feeding unit.

Reference numeral 103 denotes an auxiliary roller for preventing the sheet bundle from tilting when the sheet is set.

In FIG. 2, reference numerals 201 and 204 denote separation / feed means (feed roller 101 and separation pad 10).
2) Reference numerals 202 and 203 denote a feed guide surface 104 of the sheet conveyed from the stacking unit and a feed guide surface 2 respectively.
This is a curved surface that smoothly connects and guides 01 and 204.

The transport guide surface 104 and the bent surface 20
2, and the feed guide surface 201, or the transport guide surface 104, the bent surface 203, and the feed guide surface 20
4 constitutes a guide for leading the leading ends of the plurality of sheets to the separating and feeding means by gradually shifting them one by one in the feeding direction.

Reference numeral 205 denotes a detection sensor lever for detecting a paper jam (jam). The head falls down as shown by the arrow in the paper transport direction while the paper passes, and returns to the original position after the paper passes. The jam can be detected by returning to.

The main body of the detection sensor is not shown.

First, when the sheet bundle S is set on the sheet feed tray, the sheet bundle S is conveyed by its own weight along the conveyance guide surface 104, passes through the bent surfaces 202 and 203, and forms an obtuse angle with the conveyance guide surface 104. Intersecting feed guide surfaces 201, 204
Hit.

Accordingly, the uppermost sheet of the plurality of sheets (sheets) approaches the feeding direction most, and gradually shifts in the opposite direction toward the lower side.

Then, as shown in FIG. 2, after the sheet bundle S is set on the sheet feeding tray and the sheet feeding is started, the leading end of the sheet is rotated by the feed roller 101 as shown in the figure. , Are further separated from the uppermost sheet by the sheet conveying guide surfaces 202 and 204 so as to approach the separation pad.

At this time, the paper bundle S is not always completely separated one by one. In particular, thin papers and the like are handled in various ways, and in some cases, the leading ends are slightly shifted and overlap. In some cases, double feed of about two or three sheets may be performed at this stage.

After the leading ends are thus preliminarily separated, the sheets are finally separated one by one with a separation pad.

Therefore, even if the paper is slightly multi-fed as described above, it is surely separated here.

The force required for the separation is about several tens of grams if the contact angle of the separation pad 102 to the paper is appropriate.

In the actual design, it is necessary to support the weight of the paper bundle, so that the urging condition of one hundred and several gram was required.
This was sufficient for the breakdown of the acting force.

In the image processing apparatus shown in FIG. 3, the separated paper completes predetermined image processing (image reading) by the image reading section 502 as shown in the figure, and is sequentially discharged out of the machine.

As described above, the two basic operations of separating a sheet by a person (the operation of separating the leading end of the sheet and the friction separating operation) are applied to the apparatus, and the separating operation of the separating and feeding means is performed. Since the front end of the sheet is preliminarily separated before the sheet feeding, the sheet can be reliably separated and fed without imposing a load on the separation feeding means.

As for the paper transport function, the occurrence rate of paper jam (jam) and double feed depends on the type of paper, but is 1/3.
It was possible to hold down to about 500 to 1/40000 (sheets).

Further, since the sheets can be separated by the simple structure as described above, there is almost no need to add auxiliary means in terms of parts cost and sheet separation and transportability. It was possible to hold down to about 1/3 to 1/5.

(Second Embodiment) FIGS. 5 and 6 show a second embodiment of the present invention. In the above-described first embodiment, the configuration in which the front end of the sheet is separated by the guide alone is described. However, in the present embodiment, the configuration in which the front end of the sheet is separated by the guide and the separation pad forming the separation feeding unit is illustrated. . For other configurations and actions, refer to
Therefore, the same components are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 5 is a schematic front view of a main part of a sheet feeding apparatus according to a second embodiment of the present invention, and FIG. 6 is a sectional view of FIG. 5 ((a) is an AA section in FIG. 5). Figure, (b)
Is a sectional view taken along the line BB in FIG. 5).

In this embodiment, the separation pad 302
On the side, a paper transport guide member 401 is provided as a guide, and the shape is such that the leading end of the sheet can be easily separated.

As shown in the figure, a part of the surface of the friction separating member 402 is projected from the transport guide surface 403 by δ in the figure.

That is, in the first embodiment, the guide is provided on the apparatus main body side, and the leading end of the sheet is separated by the guide alone. In this embodiment, the guide is separated from the paper transport guide surface 406 of the guide. Friction separation member 4 for pad 302
02, the front end of the sheet is divided.

(Third Embodiment) FIG. 7 shows a third embodiment of the present invention. A configuration is shown in which a thin plate having flexibility is provided on the upstream side of the separation pad in the above embodiment to prevent the leading end of the curled sheet from biting into the surface of the separation pad. Other configurations and operations are the same as those in the above-described embodiment.
The same components are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 7 is a schematic sectional view of a main part of a sheet feeding apparatus according to a third embodiment of the present invention.

Sheets with poor sheet transportability in sheet transport include thick paper, paper with large cutting burrs, and a sheet having a warp (curl) in the direction away from the feed roller 804.

Further, in some cases, a so-called no pick may occur, in which the leading end of the sheet does not advance by cutting into the surface of the separation pad.

In the present embodiment, in consideration of such a case, the separation point 803 on the separation / transport surface of the separation pad 802 is considered.
On the further upstream side, a flexible sheet member (thin plate) 801 is provided as a pressing means for pressing the sheet front end against the roller side to prevent the sheet front end from being caught at the start of sheet feeding.

The sheet member 801 is designed to have such a flexibility that the sheet member 801 is in close contact with the conveyance surface of the separation pad when paper is fully loaded.

(Fourth Embodiment) FIG. 8 shows a fourth embodiment of the present invention. In the above-described embodiment, the configuration in which the separation pad is urged to the feeding roller has been described. In the present embodiment, the separation pad is fixed and the surface is separated and fed by the feeding roller having flexibility. Is shown. Other configurations and operations are the same as those of the above-described embodiment, and therefore, the same components are denoted by the same reference numerals and description thereof will be omitted.

FIG. 8 is a schematic sectional view of a main part of a sheet feeding apparatus according to a fourth embodiment of the present invention.

In this embodiment, a configuration is shown which is applied to a low cost specification in which the required number of sheets to be loaded is originally as small as about 5 to 6 sheets.

In the case of such an apparatus, as shown in the figure, the urging means of the separation pad 902 is omitted, the separation mechanism is made rigid, and the reaction force 901 due to the bending deformation of the feeding roller 903 is made of paper ( The sheet is used as a separating / transporting force.

The same effects can be obtained by applying the guide described in each of the above embodiments to such an apparatus.

(Fifth Embodiment) FIG. 9 shows a fifth embodiment of the present invention. FIG. 9 is a main sectional view of an image forming apparatus to which an electrophotographic process is applied. In the above-described embodiment, the configuration in which the sheet is separated immediately before the separation unit by the feeding roller and the separation pad is described. However, in the present embodiment, the guide is located upstream of the position where the feeding roller and the separation pad are arranged. Is provided, and after the sheet is sufficiently cut, the sheet is guided to the separation unit by the feeding roller and the separation pad. Other configurations and operations are the same as those of the above-described embodiment, and therefore, the same components are denoted by the same reference numerals and description thereof will be omitted.

FIG. 9 is a schematic sectional view of a main part of a sheet feeding apparatus according to a fifth embodiment of the present invention.

As shown in FIG.
A paper transport guide 1101 is arranged upstream of the paper feed tray, and at this position, the leading edge of the paper stacked on the paper feed tray 1105 is separated before separation.

In the drawing, reference numeral 1103 denotes an image forming unit for forming an image on a sheet, and 1104 denotes a fixing device for fixing an unfixed toner image formed on the sheet.

In this configuration, since the weight of the paper bundle S is hard to directly apply to the separation pad 1106, the separation pressure urging force required for separating the paper is 1/2 to the conventional one.
Only about 1/3 is needed.

(Other Embodiments) In the above-described embodiment, the case where the paper (sheet) enters obliquely above the separation friction surface has been described. May be adopted.

The friction surface of the separation pad at the separation position and the paper conveyance guide surface may or may not be parallel.

Further, the image processing apparatus is not limited to an image scanner, but can be applied as a sheet feeding apparatus provided in an apparatus for reading or forming an image such as a copier, a printer, or a facsimile apparatus. .

The sheet feeding device may be provided integrally with the image processing device, or may be a detachable separate device.

As described above, the present invention is not limited to one mode and configuration, and several modified configurations are possible.

[0105]

According to the sheet feeding apparatus of the present invention, since the leading end of the sheet is gradually shifted by the guide and then separated and fed one by one by the separating feeding means, the sheet is reliably formed with a simple structure. Can be separated and fed, and the reliability is improved.

The separating and feeding means may be constituted by a roller and a friction member which is urged in the direction of the roller, and may be arranged so as to be in contact with the friction member and the surface of the friction member. It can also be constituted by a roller having a flexible surface.

If the pressing means is provided, the leading end of the sheet is pressed against the roller, so that even the curled sheet can be reliably fed by the roller.

The pressing means may be a thin plate having flexibility.

The guide has a transport guide surface portion and a feed guide surface portion, so that a plurality of sheets transported on the transport guide surface portion are applied to the feed guide surface portion,
The leading end of the sheet can be gradually shifted one by one from the front side in the feeding direction.

Further, if a bent surface connecting the transport guide surface and the feed guide surface is provided, the sheets conveyed by the transport guide surface can be smoothly guided to the feed guide surface while being shifted one by one.

[0111] If the bent surface portion is arranged upstream of the separating section by the separating / feeding means, the burden on the separating / feeding means can be further reduced.

Further, the image processing apparatus of the present invention includes reading means for reading a document image of a document sheet conveyed by the highly reliable sheet feeding apparatus as described above,
On the sheet conveyed by the above sheet feeding device,
An image forming unit for forming an image may be provided.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a main part of a sheet feeding apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view in FIG. 1 ((a) is A in FIG. 1);
2A is a sectional view, and FIG. 2B is a sectional view taken along line BB in FIG.

FIG. 3 is a schematic configuration diagram of an image processing apparatus including a sheet feeding device according to the first embodiment of the present invention.

FIG. 4 is an operation explanatory diagram illustrating an operation in the sheet feeding apparatus according to the first embodiment of the present invention.

FIG. 5 is a schematic front view of a main part of a sheet feeding apparatus according to a second embodiment of the present invention.

6 is a sectional view of FIG. 5 ((a) is A in FIG. 5).
A sectional view, and (b) is a BB sectional view in FIG. 5).

FIG. 7 is a schematic sectional view of a main part of a sheet feeding apparatus according to a third embodiment of the present invention.

FIG. 8 is a schematic sectional view of a main part of a sheet feeding apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view of a main part of a sheet feeding device according to a fifth embodiment of the present invention.

FIG. 10 is a schematic configuration perspective view of an image processing apparatus.

FIG. 11 is a schematic sectional view of the configuration of an image processing apparatus according to the related art.

[Explanation of symbols]

101, 804, 903, 1102 Feed roller 102, 302, 802, 902, 1106 Separation pad 103 Auxiliary roller 104, 403 Transport guide surface 201, 204 Feed guide surface 202, 203 Bent surface 401 Paper transport guide member 402 Friction separation Member 501 Feed separation mechanism 502 Image processing mechanism 801 Sheet member 1101 Paper transport guide 1105 Feed tray

Claims (12)

[Claims] 1. A sheet feeding apparatus comprising: a stacking unit for stacking a plurality of sheets; and a separation feeding unit for separating and feeding the sheets stacked on the stacking unit one by one. A sheet feeding apparatus, wherein a guide for leading the leading end of the sheet to the separation feeding unit by gradually shifting the leading end of the sheet one by one in the feeding direction is provided upstream of the separation feeding unit. 2. The sheet feeding apparatus according to claim 1, wherein said separation feeding means has a roller and a friction member biased in a direction of said roller. 3. The separating / feeding means according to claim 1, further comprising: a friction member; and a roller disposed so as to be in contact with the surface of the friction member and having a flexible surface. 2. The sheet feeding device according to 1. 4. The sheet feeding device according to claim 2, further comprising a pressing unit that presses a leading end of a sheet against the surface of the roller at a position upstream of a separation unit formed by the separation feeding unit. apparatus. 5. The sheet feeding apparatus according to claim 4, wherein said pressing means is a thin plate having flexibility. 6. The sheet feeding device according to claim 1, wherein the sheets stacked on the stacking section are conveyed along a conveying surface by their own weight. 7. A conveyance guide surface portion including a conveyance surface of a sheet conveyed from the stacking portion, intersects the conveyance guide surface portion at an obtuse angle, and is fed by the separation feeding means. 7. The sheet feeding device according to claim 1, further comprising a feeding guide surface portion substantially parallel to a sheet feeding surface. 8. The sheet feeding device according to claim 7, wherein the guide has a bent surface portion connecting the transport guide surface portion and the feed guide surface portion. 9. The sheet feeding device according to claim 7, wherein a part of the surface of the friction member protrudes from the conveyance guide surface portion. 10. The sheet feeding apparatus according to claim 8, wherein said bent surface portion is disposed upstream of a separation section by said separation feeding means. 11. An image processing apparatus, comprising: reading means for reading a document image of a document sheet conveyed by the sheet feeding device according to claim 1. Description: 12. An image processing apparatus comprising an image forming means for forming an image on a sheet conveyed by the sheet feeding apparatus according to any one of claims 1 to 10.