JP2001130769A - Sheet feeding device and image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a plurality of documents from being delivered when the document having both surface having image information are separately fed, and to prevent the document from being dirtied when a plurality of documents are delivered to a separating nip. SOLUTION: The device is provided with a loading tray 2 on which a plurality of documents can be loaded, a delivery roller 4 capable of being brought into contact with and separated from the documents loaded on the loading tray 2 and for delivering the document while being in contact with the document, a feed roller for feeding the document delivered by the delivery roller 4, and a separating pad 6 for separating the documents one by one by being in pressure-contact with the feed roller. The relationship between the moving speed V1 to the contact position of the delivery roller to the document in a case where image information is provided on one surface of the loaded document and the moving speed V2 to the contact position of the delivery roller to the document in a case where image information are provided on both surfaces of the loaded document is set to V1>V2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus used in an image processing apparatus such as a scanner or a copying machine. For example, the present invention relates to an automatic sheet feeding apparatus for separating a plurality of placed originals into one and supplying the original to an image reading apparatus. It relates to a device that can be used as a document supply device.

[0002]

2. Description of the Related Art Conventionally, as an example of a sheet feeding apparatus used in an image processing apparatus, there is known an automatic sheet feeding apparatus for a book scanner which is provided with a function of reading a sheet by feeding a sheet to a book scanner in which a document is fixedly read. ing. This type of apparatus includes a document placement table, a paper discharge tray, and a document separation unit, a document conveyance unit, and a paper discharge unit arranged on one side of the scanner main body. And the document tray and the discharge tray are arranged in a vertical relationship with each other by being rotated by 180 °.

In this conventional apparatus, a document placing table and a paper discharge tray are arranged in a vertical relationship with each other, so that reading of a fixed document and reading of a fed document are realized in a compact configuration.

In the above-described conventional sheet feeding apparatus, as shown in FIG. 15, a feeding roller 502 comes into contact with a plurality of documents P placed on a document mounting table 501, and the rotation of the feeding roller 502 is controlled. The original P is fed out, and the fed-out original P is separated one by one between the feed roller 503 and the separation pad 504 pressed against the roller 503, and is fed toward the reading position. I have.

The document P is supplied in the same manner regardless of whether the document P has image information on one side or image information on both sides.

[0006]

In the above-mentioned conventional apparatus,
Regardless of a document having image information on one side or a document having image information on both sides, a plurality of documents P stacked on the document table 501 are fed out by a feeding roller 502 capable of contacting / separating. Original P is fed by the feed roller 50
The sheet is separated into one sheet at a separation nip by the separation pad 3 and the separation pad 504 and fed.

Here, for example, in the case of a document having image information on one side, an image such as a toner, a pencil or a pen is placed on one side (front side) and the back side is blank, so that a plurality of the originals are fed out. Even if one document enters the separation nip, the white paper surface (back surface) of the uppermost document being separated and conveyed comes into contact with and presses against the edge (end) of the second document, so that the edge and back surface of the original document are The image is offset and no smear occurs.

However, in the case of a document having image information on both sides, since images are placed on both sides, if the document is fed out a plurality of times and the plurality of documents enter the separation nip, the document during separation and conveyance is When the image surface (back side) of the top document comes into contact and pressure contact with the edge (end) of the second document, the image is offset to the edge or back side of the original,
There was a risk that the original would be dirty.

Accordingly, an object of the present invention is to prevent a plurality of originals from being fed out when separating and feeding an original having image information on both sides, and to prevent a plurality of originals from entering the separation nip. The purpose is to prevent the resulting document from being stained.

[0010]

In order to achieve the above object, a typical configuration of the present invention comprises a stacking means capable of stacking a plurality of sheets, and an abutting contact with the sheets stacked on the stacking means. Feeding means for contacting the sheet and feeding out the sheet, feeding means for feeding the sheet fed by the feeding means, and pressing the sheet against the feeding means to separate the sheets one by one. Separating means for separating, when the loaded sheet is a sheet having image information on one side, a moving speed V1 of the feeding means to the contact position of the sheet with respect to the sheet, and the loaded sheet provides image information on both sides. In the case of a sheet having the same, the relation between the moving speed V2 of the feeding means to the contact position and the sheet is V1> V2.
It is characterized by having comprised so that it might become.

According to the above construction, the moving speed V2 of the feeding means to the sheet having image information on both sides to the contact position is set to be greater than the moving speed V1 of the feeding means to the sheet position having image information on one side to the contact position. In addition, since the sheet feeding force by the feeding unit is reduced by delaying the feeding, it is possible to prevent a plurality of sheets from being fed out, and to prevent the sheet from being stained when the plurality of sheets enter the separation unit. Can be prevented.

Further, in addition to the above configuration, the feeding speed V3 of the feeding means when feeding the sheet having the image information on one side and the feeding speed V4 of the feeding means when feeding the sheet having the image information on both sides are provided. , The above-described effect is further enhanced.

Further, the feeding speed V4 of the feeding means is
After feeding out the sheet having the image information on both sides, the conveying speed V3 of the sheet having the image information on one side
By using the same speed as that described above, the sheet throughput (total transport time) is improved.

The feeding means is swingably supported by an arm member with respect to the feeding means.
The feeding means is configured to rotate and swing by transmitting the rotation of the feeding means, and further, a torque limiter is disposed between the feeding means and the arm member, whereby the feeding means is brought into contact with the stacked sheets. The subsequent contact force on the sheet is kept substantially constant by the action of the torque limiter.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sheet feeding apparatus to which the present invention is applied will be described below with reference to the drawings.

In the following description, as an embodiment of the sheet feeding device, an automatic document feeding device for feeding a document to an image reading device in a copying machine as an image processing device is described.

In the order of the following description, first, the schematic configuration of the entire copying machine having the automatic document feeder will be briefly described, and then the automatic document feeder to which the present invention is applied will be described in detail.

[Schematic Configuration of Copying Machine] First, the schematic configuration of a copying machine as an image processing apparatus will be briefly described with reference to FIG.

As shown in FIG. 1, an automatic document feeder (ADF) 1, which is a sheet feeder to which the present invention is applied, is installed at an upper portion of a copying machine main body 50 so as to be openable and closable. In the automatic document feeder 1, the documents P stacked on the stacking tray 2 arranged above are sequentially separated and fed one by one from the uppermost sheet thereof. The document is conveyed to a platen glass (platen), the image of the document is read while being conveyed, and when the reading of the image is completed, the document is discharged and stacked on a discharge tray 3. The details of the automatic document feeder 1 will be described later.

The copier main body 50 is composed of a reader section 60 as reading means and a printer section 70 as recording means.

The reader section 60 optically reads image information recorded on the document P, photoelectrically converts the image information, and inputs it as image data. The reading section platen 51, book platen 52, lamp 61 and mirror 62 Scanner unit 63, mirrors 64 and 65, lens 66, image sensor 67, and the like. When reading a document using the automatic document feeder 1, the scanner unit 63 is stopped at the reading position 53 to read an image of the document moving on the flow reading platen 51, and the automatic document feeder 1 is not used. Reads an image of a document placed on the platen 52 by moving the scanner unit 63.

The printer section 70 is an image forming means using a well-known electrostatic latent image formation. In the printer section 70, reference numeral 71 denotes an upper cassette. Sheets, which are recording media in the cassette, are separated and fed one by one by the action of a separation claw and a feeding roller 72, and are guided to registration rollers 77. Reference numeral 73 denotes a lower cassette. Sheets in the cassette are separated and fed one by one by the action of a separation claw and a feeding roller 74, and are guided to registration rollers 77. A manual guide 75 guides sheets one by one to a registration roller 77 via a roller 76. Reference numeral 78 denotes a sheet deck, which includes a middle plate 78a which is moved up and down by a motor or the like. The sheets on the middle plate are separated and fed one by one by the action of a feeding roller 79 and a separating claw, and guided to a conveying roller 80. Transport roller 8
0 leads to the registration roller 77.

Reference numeral 81 denotes a photosensitive drum; 82, a primary charger for uniformly charging the drum surface; 83, an optical unit for irradiating image light (image information) to the drum surface to form an electrostatic latent image; A developing unit for forming a toner image corresponding to image information on the drum surface; a transfer charger 85 for transferring the toner image on the drum surface to a sheet; a separation charger 86; and removing residual toner on the drum surface after transfer Cleaning unit, which constitutes an image forming unit.

Reference numeral 88 denotes a conveyor belt for conveying the sheet on which the image is formed, 89 denotes a fixing device for fixing the transferred toner image to the sheet, 90 denotes a conveying roller, and 91 denotes a diverter. The sheet on which the image is formed is guided to a discharge roller 92 by a diverter 91, and is conveyed into a sorter 93. The sorter 93 has a non-sort tray 94, a sort bin tray 95b, a non-sort tray discharge roller 96, and a sort bin tray discharge roller 97. The non-sort tray 94 and the sort bin tray 95 move up and down to sort sheets one by one. . Note that a discharge tray may be mounted in place of the sorter 93.

In the case of double-sided copying or multiple copying, the sheet after fixing is branched by a diverter 91 and conveyed by conveying rollers 101. In the case of double-sided copying, a belt 1 is used.
02, 104, the path 106, and the discharge roller 105, the sheet is discharged to the intermediate tray 100. 109 and 110 are half-moon rollers for feeding a sheet, 111 is a separation roller pair, 11
3, 114 and 115 are conveying rollers for conveying the sheet to the registration roller 77.

[Schematic Configuration of Automatic Document Feeder] Next, the automatic document feeder 1 to which the present invention is applied will be described in detail. FIG. 2 is a sectional view of an automatic document feeder to which the present invention is applied, and FIG. 3 is a partial sectional view thereof.

The automatic document feeder 1 according to the present embodiment
It has a single-sided reading mode for reading the image information while transporting a document having image information on one side, and a double-sided reading mode for reading the image information while transporting a document which may have image information on both sides. Hereinafter, each reading mode will be briefly described along the flow of the conveyed document.

First, the flow of a one-sided original in the one-sided reading mode will be briefly described together with a brief description of the schematic configuration of the automatic document feeder 1.

As shown in FIGS. 2 and 3, the automatic document feeder 1 has a loading tray 2 as loading means, and loads documents on the surface of the loading tray 2.

In the document feeder of the automatic document feeder 1, a feed roller 4 serving as feed means draws a bundle of documents stacked on the stacking tray 2 into the separation units 5 and 6, and feeds the separation unit. The uppermost sheet of the document bundle is separated one by one by a feeding roller 5 as a means and a friction separating pad 6 as a separating means, and is conveyed to first registration rollers 7a and 7b. The first registration rollers 7a and 7b are stopped when the leading edge of the document arrives. After the first registration rollers 7a and 7b form a loop by carrying the sheet by the feeding roller 5 to correct skew, the first registration rollers 7a and 7b carry the document to a document carrying unit described later.

In the document feeder of the automatic document feeder 1, the document fed from the above-mentioned document feeder is fed to the lead roller 8, the second registration roller 9, the lead roller 10, the lead roller 1 and the like.
1, the paper is conveyed between the flow reading platen 51 and the white plate 12 at a predetermined speed. At this time, a scanner unit 63 (see FIG. 1) as an exposure device is fixed below the reading position 53 on the moving reading platen 51, and performs an exposure operation (read operation).

In the document discharge section of the automatic document feeder 1, while the exposure operation is being performed at the reading position 53, the discharge roller 1
3a and 13b are separated from each other, but after the rear end of the document has passed the reading position 53 and reading has been completed, the ejection roller 13b moves upward (from the broken line position to the solid line position), and moves the document to the ejection roller 13a. The sheet is nipped with the discharge roller 13b, and is discharged onto the discharge tray 3 on the back side.

In FIGS. 2 and 3, S1 is a size sensor for detecting the size of the document by detecting the leading and trailing edges of the document, S2 is a width sensor for detecting the width of the document,
S3 is a read sensor that detects the leading edge of the document and notifies the reader unit 60 of the copying machine main body 50, and S4 is a paper discharge sensor that detects the leading edge and the trailing edge of the document.

Next, the flow of a two-sided document in the two-sided reading mode will be briefly described.

First, the originals stacked on the stacking tray 2 are separated one by one by the original feeding section and conveyed to the original conveying section. In the document conveying section, the document is conveyed between the platen 51 and the white plate 12 at a predetermined speed as in the case of the single side. At this time, the scanner unit 63 as an exposure device is fixed below the reading position 53, and an exposure operation (read operation) of the first surface is performed.

The trailing edge of the original is detected by a paper ejection sensor S4.
, The discharge rollers 13a and 13b rotate in the reverse direction, and switch the document back to the second registration roller 9 of the document transport section located in the direction opposite to the document discharge direction to convey the document. The second registration roller 9 is stopped when the leading edge of the document arrives, forms a loop by driving the ejection rollers 13a and 13b, performs skew correction on both sides, and transports the document to the document transport unit.

The document transport unit performs an exposure operation (reading operation) on the second back surface in the same manner as the first surface, and then transports the document to the document discharge unit.

In the document discharge section, the document feeder 1 of this embodiment has a face-up state after reading the second back side (a state in which the first side faces upward from the apparatus). ), The order of the originals to be discharged is out of order, that is, the originals stacked in the page order on the stacking tray 2 are out of order in the page on the discharge tray 3, and it is necessary to perform re-inversion. is there. for that reason,
In the document discharge section, after the rear end of the document has passed through the paper discharge sensor S4, the discharge rollers 13a and 13b rotate in the reverse direction, and convey the document again in the direction of the document conveyance section. At this time, since only the reversing operation of the document surface is performed in the document transport unit to perform backside discharge, the skew correction is not performed by the second registration roller 9.

The original that has passed through the original transport section is transported again to the original discharge section, nipped by the discharge rollers 13a and 13b, and discharged onto the discharge tray 3 on the back side. As a result, the document is discharged in a face-down state in which the first surface faces downward from the apparatus.

[Structure and Operation Around the Feeding Roller] Here, the structure and the operation around the feeding roller will be described in detail. 4A and 4B are explanatory views showing the vicinity of the feeding roller, where FIG. 4A is a top view and FIG. 4B is a front view.

A feed roller 5, a swing arm 22, which is an arm member, and a pulley 23 are coaxially supported on the feed shaft 21, and the swing arm 22 is disposed on both sides of the feed roller 5. You. The rotation of the pulley 23 is restricted by a pin (not shown) with respect to the feeding shaft 21.
Rotates with 1. The feed roller 24 and the other end of the swing arm 22 are pivotally supported by the feed shaft 24, and a belt 25 is delivered.

When the feed shaft 21 rotates in the direction of arrow a in the figure by a drive motor (not shown),
The feed roller 5 rotates in the feeding direction (direction of arrow a) via the belt, and the feeding roller 4 also rotates in the feeding direction (direction of arrow c) via the belt 25.

In order to feed out the original on the stacking tray 2, the swing arm 22 is driven in the direction of the arrow b by a driving means using a well-known spring clutch (torque limiter). That is, a boss 22a is formed on a part of the swing arm 22, and a torsion spring 26 is provided to rewind the boss 22a so that the boss 22a can be tightened.
The other end 26 a of 6 is hooked on the groove 23 a of the pulley 23, and its rotation is restricted. Accordingly, when the feed shaft 21 rotates in the direction of arrow a, the pulley 23 rotates, and the swing arm 22 swings in the direction of arrow b via the torsion spring 26, so that the feeding roller 4 moves on the stacking tray 2. Contact the manuscript.

When the feeding roller 4 comes into contact with the upper surface of the original on the stacking tray 2, the feeding roller 4 is further pressed in the direction of arrow b. However, the outer diameter of the torsion spring 26 becomes very small, and the boss of the swing arm 22 becomes bossed. Tightening of the boss 22a and the torsion spring 26 is reduced (torque limiter).

This sliding force, that is, the feeding roller 4
Is determined by the specification of the torsion spring 26 and the tightening frictional force between the boss 22a. The parameters for feeding the original include the pressing force of the feed roller 4, the moving speed of the feed roller 4 in the direction of arrow b at which the original roller 4 collides with the original, and the transport speed of the feed roller 4.
If the feeding force is large, a plurality of documents are fed, and the plurality of documents enter the separation nip. Note that the lower the moving speed and the conveying speed of the feeding roller 4, the smaller the above-mentioned feeding force.

The separation nip is formed by a feed roller 5 and a separation pad 6 which is pressed against the roller 5. When a plurality of documents on the stacking tray 2 are picked up by the feed roller 4, the fed document is Even if a plurality of sheets are fed out, the operation of the second and subsequent documents is prevented by the action of the separation pad 6 in the separation nip. In addition, if only one original is fed, a plurality of originals do not enter the separation nip.

Here, for example, when the single-sided reading mode described above is selected, an image such as a toner, a pencil or a pen is placed on one side (front side) and the back side is blank, so that a plurality of originals are fed out. Even if the plurality of originals enter the separation nip, the blank surface (back side) of the topmost original being separated and conveyed is the edge of the second original (the downstream end in the conveyance direction).
, The image is offset on the edge and the back side of the document, and is not stained.

On the other hand, when the double-sided reading mode is selected,
Since an image is placed on both sides of the original, a plurality of originals are fed out, and when the plurality of originals enter the separation nip, the image surface (back side) of the uppermost original being separated and transported has two sheets. The contact and press contact with the edge (edge) of the eye original may offset the image on the edge or the back side of the original, and may stain the original.

Therefore, in the present invention, the moving speed V1 of the feeding roller 4 to the contact position with respect to the original in the single-sided reading mode and the moving speed V1 of the feeding roller 4 with respect to the original in the double-sided reading mode. The relationship with V2 is
The configuration is such that V1> V2.

Further, the feeding speed V3 of the feeding roller 4 when feeding a document having image information on one side, and the feeding roller 4 when feeding a document having image information on both sides.
Is also configured to satisfy V3> V4.

Accordingly, the moving speed and the conveying speed of the feed roller 4 in the single-sided reading mode are set to V1 and V3, which are equal to or slightly faster than the conveying speed of the document conveying section following the separation and conveying, so that the reading productivity is improved. There is no drop.

On the other hand, in the double-sided reading mode, the preceding document repeats the above-mentioned switchback conveyance, and there is a margin for the time. , V4 (V1> V2, V3> V4). Therefore, in the double-sided mode, the feeding force of the feeding roller 4 is reduced, and a plurality of documents do not enter the separation nip.

The feeding roller 4 in the both-side reading mode
Is set to V4 only at the time of feeding, and thereafter,
The same effect can be obtained with a configuration returning to 3.

In this embodiment, both the moving speed V2 and the conveying speed V4 of the feeding roller 4 in the double-sided reading mode are set to be lower than those in the single-sided reading mode (moving speed V1 and conveying speed V3). Although illustrated, the invention is not limited to this. For example, even when one of the moving speed V2 and the transport speed V4 of the feeding roller 4 is set to be slower than the moving speed V1 and the transport speed V3, it is possible to prevent a plurality of documents from entering the separation nip. .

According to the above-described configuration, an image is placed on both sides of a document in the double-sided reading mode. However, since a plurality of documents do not enter the separation nip, the document is not stained. Therefore, in the double-sided reading mode, it is possible to prevent the original from being stained when a plurality of originals enter the separation nip.

[Structure of Guide Rib] Next, the guide rib provided on the same surface as the pre-separation pad on the upstream side of the separation pad will be described. FIG. 5 is a schematic diagram of a document feeding unit.
In the drawing, 14 is a pre-separation pad, and 15 is a guide rib.

In the present embodiment, as shown in FIG. 6, a total of six guide ribs 15 are provided on each side of the pre-separation pad 14 so as to be at the same height as the surface of the pre-separation pad 14. I have.

Accordingly, the originals stacked on the stacking tray 2 are pulled in by the feeding roller 4 and are divided into a bundle of several originals. At this time, the leading end of the document bundle hits the surface of the pre-separation pad 14 and the guide rib 15, and is shifted and enters the nip between the feed roller 5 and the friction separation pad 6. The separation units 5 and 6 separate only the uppermost sheet of the conveyed document bundle by one sheet and convey it to the first registration rollers 7a and 7b. The first registration rollers 7a and 7b are stopped when the leading edge of the document arrives, and form a loop by carrying the feeding roller 5 to correct skew, and then carry the document to the document carrying unit.

According to the above configuration, compared to the case where the pre-separation operation is performed only by the pre-separation pad 14, the leading end of the original receives a greater resistance, and the original bundle can be reliably shifted. The effect of preventing the bundle stab is obtained.

[Bending Configuration of Document Holding Member]
The configuration of the document pressing member provided in the transport path will be described. An elastic sheet-like film is used as the document pressing member in the present embodiment. For example, a polyester film (trade name Mylar) is used.

First, FIGS. 7 and 8 show a first configuration example of the tip bending mylar. FIG. 7 is a schematic diagram of a document feeding unit.
In the figure, reference numeral 16 denotes a registration loop mylar disposed before the first registration rollers 7a and 7b.

With respect to the originals stacked on the stacking tray 2, the feed roller 4 draws the bundle of originals stacked on the stacking tray 2 into the separation units 5 and 6, and the feed roller 5 and the friction separation pad 6
, The uppermost sheet of the document bundle is separated one by one and conveyed to the first registration rollers 7a and 7b. First registration roller 7
A and 7b are stopped when the leading edge of the document arrives, and after the sheet is conveyed by the feeding roller 5 to form a loop to correct the skew, the document is conveyed to the document conveying unit.

At this time, due to the elasticity of the mylar itself, the registration loop mylar 16 alleviates the shock of the original when the loop disappears when the original is conveyed after the skew correction, and as a result, reduces the loop disappearing sound. There is.

In the present embodiment, the shape of the tip of the registration loop mylar 16 is changed from the conventional shape shown in FIG.
From the position equal to the mylar tip position shown in FIG.
By changing the front end of the mylar 16 to the bent shape shown in FIG. 8B, a bent portion is applied to the document P instead of the edge of the front end of the mylar 16.

As a result, it is possible to reduce the generation of paper dust and toner dust due to the rubbing between the original and the edge of the mylar, and to satisfy the performance as a conventional resist loop mylar.

Next, FIGS. 9 and 10 show a second configuration example of the tip bending mylar. FIG. 9 is a schematic diagram of a document transport unit. In the figure, reference numeral 17 denotes a document pressing mylar. Also, on the copying machine main body side, 51 is a reading platen,
54 is a jump stand.

In the document feeder, the document fed from the document feeder is flowed between the platen 51 and the white plate 12 at a predetermined speed by the lead roller 8, the second registration roller 9, the lead roller 10 and the lead roller 11. To be transported.

At this time, the scanner unit 63 (see FIG. 1) as an exposure device is fixed below the reading position 53 on the moving reading platen 51, and performs an exposure operation (read operation).

Then, the original pressing mylar 17 presses the original being conveyed against the jump table 54 due to the elasticity of the mylar, and reduces irregularities in the conveying speed on the reading position 53.

In the present embodiment, the shape of the tip of the document holding mylar 17 is changed from the conventional shape shown in FIG. 10A to the tip of the mylar 17 from a position equal to the mylar tip position shown in FIG. The bent shape shown in FIG. 10B is changed, and the bent portion is applied to the document P instead of the edge portion of the front end of the mylar 17.

As a result, it is possible to reduce the generation of paper dust and toner dust due to the rubbing between the original and the edge of the mylar, and to satisfy the performance as a conventional original pressing mylar.

[Sheet Ribbing Rib] Next, a description will be given of the configuration of a rib for stiffening a document to be discharged according to the waist (rigidity) of the document to be discharged.

FIG. 11 is a sectional view showing a document discharge section.
The discharge roller 13a is pressed against the discharge roller 13a /
The paper discharge rib 13 has a leading end protruding so as to bite into a sheet path by the urging force of a separation roller 13 b and a compression spring 19 which can be separated.

The paper discharge waving rib 18 is rotatable to the position shown in FIG. 12, is positioned in the biting direction by the compression spring 19, and escapes when the document P enters the discharge rollers 13a and 13b. I have.

Further, the relief amount of the paper discharge waist rib 18 changes depending on the waist (rigidity) of the document P. That is, when the original P is a thin paper having no stiffness, the spring force of the compression spring 19 is superior, and the paper ejection stiffening rib 18 does not move. Conversely, in the case of thick paper having strong stiffness, the spring force of the compression spring 19 is lost, and
8 moves.

By the above-described operation, as shown in FIG. 13, when the original P is thin paper having no stiffness, the original P is changed so as to undulate. On the other hand, as shown in FIG. In the case of thick paper, the orientation of the document P does not change.

As a result, regarding the discharge stackability of the original P,
When the original P is a thin paper without a waist, the original P is discharged in a posture waving vertically, so that the original P has a waist,
The leading end of the discharge tray 3 is not rounded and is not disturbed during stacking. When the document P is a thick paper having a strong waist, the paper itself has a waist, and the leading end does not become rounded. Also,
Regarding the torque load for rotating and driving the ejection rollers 13a and 13b, the thickening rib escapes with thick paper, so that the load does not become heavy.

Accordingly, it is possible to achieve both the discharge stackability and the roller driving load, from thin paper (stiff sheet) to thick paper (stiff sheet).

In the above configuration, the compression spring 19 is exemplified as the urging means for projecting the tip of the paper discharge waist rib 18 so as to bite into the sheet path. However, the present invention is not limited to this. , A torsion spring, a leaf spring or the like, and the same effect can be obtained as long as the urging force is obtained.

The same effect can be obtained by other moving methods, such as a method in which the discharge waist rib moves while rotating, a method in which the rib moves in a linear direction, and a method in which the rib moves while elastically deforming.

The same effect can be obtained even if the paper discharge waist ribs 18 are integrally formed of an elastic material such as a plate spring.

Further, the paper discharge stiffening rib 18 is
Although they are arranged near both sides of 3a and 13b, the method of vertically waving the posture of the document, such as the number of arrangements and positions, is not limited.

In the above-described embodiment, a copying machine having an openable and closable automatic document feeder as a sheet feeder to which the present invention is applied has been exemplified as the image processing apparatus.
It is not limited to this. For example, the present invention is also applicable to a reading device in which a reader unit serving as a reading unit and the document supply device 1 are integrated.

[0084]

As described above, according to the present invention,
The moving speed V2 of the feeding means to the contact position of the sheet having image information on both sides is set to the moving speed V2 of the feeding means to the contact position of the sheet having image information on one side.
Since it is slower than 1, the feeding force of the sheet by the feeding means is reduced, thereby preventing a plurality of sheets from being fed out, which occurs when a plurality of sheets enter the separating section. It is possible to prevent the sheet from being stained.

Further, in addition to the above-described structure, the feeding speed V3 of the feeding means when feeding the sheet having the image information on one side and the feeding speed V4 of the feeding means when feeding the sheet having the image information on both sides are provided. Relationship is V3>
By configuring so as to be V4, the above-described effect is further increased.

Further, the transport speed V4 of the feeding means
After feeding out the sheet having the image information on both sides, the conveying speed V3 of the sheet having the image information on one side
By using the same speed as that described above, the sheet throughput (total transport time) is improved.

The feeding means is swingably supported by the arm member with respect to the feeding means.
The feeding means is configured to rotate and swing by transmitting the rotation of the feeding means, and further, a torque limiter is disposed between the feeding means and the arm member, whereby the feeding means is brought into contact with the stacked sheets. The subsequent contact force on the sheet is kept substantially constant by the action of the torque limiter.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a copying machine provided with an automatic document feeder (sheet conveying device).

FIG. 2 is a schematic sectional view of an automatic document feeder (sheet conveying device).

FIG. 3 is an enlarged sectional view of a main part of an automatic document feeder (sheet conveying device).

FIG. 4 is a top view and a side view showing a configuration around a feeding roller.

FIG. 5 is a schematic sectional view of a document feeding unit (around a pre-separation pad).

FIG. 6 is an explanatory view of a pre-separation pad and a guide rib.

FIG. 7 is a schematic cross-sectional view of a document feeding section (around the registration loop mylar).

FIG. 8 is an enlarged view of a cash register loop mylar.

FIG. 9 is a schematic cross-sectional view of a document conveying unit (around a document pressing mylar).

FIG. 10 is an enlarged view of a document holding mylar.

FIG. 11 is a schematic cross-sectional view of a document discharge unit (around a discharge roller).

FIG. 12 is a schematic cross-sectional view of a document discharge unit (around a discharge roller).

FIG. 13 is a diagram illustrating a state in which a document (thin paper having no waist) is discharged by a discharge roller and a discharge waving rib.

FIG. 14 is a diagram illustrating a state in which a document (a stiff cardboard) is discharged by a discharge roller and a discharge stiffening rib;

FIG. 15 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 P: Document S1: Size sensor S2: Width sensor S3: Lead sensor S4: Discharge sensor 1: Automatic document feeder 2: Loading tray 3: Discharge tray 4: Feeding roller 5: Feeding roller 6: Friction separation pad 7a , 7b ... first registration roller 8 ... lead roller 9 ... second registration roller 10 ... lead roller 11 ... lead roller 12 ... white plate 13a, 13b ... discharge roller 14 ... pre-separation pad 15 ... guide rib 16 ... registration loop mylar 17 ... original Retainer Myr 18… Paper discharge waisting rib 19… Compression spring 21… Feed shaft 22… Swing arm 22a… Boss 23… Pulley 23a… Groove 24… Extending shaft 25… Belt 26… Torsion spring 26a… Other end 50… Copy Machine body 51… Pane reading platen 52… Book platen 5 ... Reading position 54 ... Jump table 60 ... Reader unit 61 ... Lamp 62 ... Mirror 63 ... Scanner unit 64,65 ... Mirror 66 ... Lens 67 ... Image sensor 70 ... Printer unit 71 ... Upper cassette 72 ... Feeding roller 73 ... Lower cassette 74 feeding roller 75 manual feeding guide 76 roller 77 registration roller 78 sheet deck 78a middle plate 79 feeding roller 80 conveying roller 81 photosensitive drum 82 primary charger 83 optical unit 84 developing Device 85 Transfer charger 86 Separation charger 87 Cleaning device 88 Conveying belt 89 Fixing device 90 Conveying roller 91 Diver 92 Discharge roller 93 Sorter 94 Non-sort tray 95 Sort bin tray 96 Non Sort tray discharge roller 9 ... sort bin tray discharge roller 100 ... intermediate tray 101 ... conveying rollers 102, 104 ... belt 105 ... discharge rollers 106 ... pass 109, 110 ... semicircular roller 111 ... pair of separation rollers 113, 114, 115 ... conveyance roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuichi Makino 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masaaki Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term (reference) 3F343 FA03 FB02 FB03 FB04 FC01 GA02 GB01 GC01 GD01 HA12 HB01 JA15 JD03 JD08 LA04 LA15 LC07 LC09 LD10

Claims (7)

[Claims] A stacking means capable of stacking a plurality of sheets, a feeding means capable of contacting and separating the sheets stacked on the loading means, and feeding the sheet in contact with the sheets; A sheet feeding unit that feeds the sheet fed by the feeding unit; and a separating unit that presses against the feeding unit to separate the sheets one by one, wherein the stacked sheet has image information on one surface. And the moving speed V1 of the feeding means to the contact position of the feeding means with respect to the sheet when the sheet is stacked, and the moving speed of the feeding means to the contact position of the sheet when the loaded sheet is a sheet having image information on both sides. The relationship with V2 is V1>
V2. 2. The relationship between the transport speed V3 of the feeding means when feeding out a sheet having image information on one side thereof and the feeding speed V4 of the feeding means when feeding out a sheet having image information on both sides, 2. The sheet feeding apparatus according to claim 1, wherein V3> V4. 3. The feeding speed V4 of the feeding means is made the same as the feeding speed V3 of the sheet having image information on one side after feeding the sheet having image information on both sides. Item 3. The sheet feeding device according to Item 2. 4. The feeding means is swingably supported by an arm member with respect to the feeding means, and is configured to rotate and swing by transmitting the rotation of the feeding means. The sheet feeding device according to any one of claims 1 to 3, wherein a torque limiter is disposed between the feeding unit and the arm member. 5. An image processing apparatus comprising: a reading unit that reads image information of a sheet; and a sheet supply unit that supplies a sheet to the reading unit. An image processing apparatus comprising the sheet feeding device according to claim 1. 6. The image processing apparatus according to claim 5, further comprising recording means for recording image information read by said reading means on a recording medium. 7. The image processing apparatus according to claim 5, wherein the image processing apparatus has a single-sided reading mode for reading image information on one side of the sheet and a double-sided reading mode for reading image information on both sides of the sheet. The image processing device according to claim 1.