JP2004137021A - Paper feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeder capable of preventing damage to a separating pad due to abutting of a sheet member and paper jam due to a step between a support body and an elastic member. <P>SOLUTION: The paper feeder 100 comprises a paper feeding tray 101 for carrying a plurality of documents in a stacking state, a paper feeding roller 102 for feeding the documents on the paper feeding tray 101 to a conveying passage, a support body 103 capable of coming into press-contact with a roller surface of the paper feeding roller 102, the separating pad 104 adhered to the support body 103 and in press-contact with the roller surface, and the elastically deformable elastic member 35 interposed between a separation surface 40 of the separating pad 104 and the support body 103. The paper feeder 100 has a guide film 105. The guide film 105 is fixed to the bottom surface of the paper feeding tray 101, is laid so that the downstream-side end 50 thereof comes into press-contact with the separation surface 40 on the upstream side of a press-contact section C between the separating pad 104 and the paper feeding roller 102, and guides the documents on the paper feeding tray 101 to the separation surface 40 of the separating pad 104. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a paper feed tray that supports a plurality of sheet members in a stacked state, a paper feed roller that feeds the sheet members on the paper feed tray to a conveyance path, and a support that can press against the roller surface of the paper feed roller. Feeder comprising a body, a separation pad attached to the support and pressed against the roller surface, and an elastically deformable elastic member interposed between the press-contact portion of the separation pad and the support. Equipment related.
[0002]
[Prior art]
Some scanners, facsimile machines, copiers and the like are equipped with a paper feeding device such as an auto document feeder (hereinafter referred to as "ADF") for sequentially feeding a plurality of originals. According to this, a plurality of documents placed on the paper feed tray can be continuously and automatically fed to the reading position. As shown in FIG. 6, a driving force is applied to the shaft 91 to separate the documents held on the sheet feeding tray in a stacking state into the transport path while separating the documents one by one. A separation mechanism 90 is provided on the paper feed roller 92 which is transmitted and rotated, and presses the separation pad 94 disposed on the upper surface of the support 93 against the paper feed roller 92 by urging the support 93. When another document adheres to the document fed into the conveyance path by the pressing and rotation of the paper feed roller 92 due to friction or static electricity, the other document is pressed at the pressure contact portion between the paper feed roller 92 and the separation pad 94. Some documents are stopped by the frictional force of the separation pad 94 to prevent double feeding of documents. Further, by providing an elastic member 95 such as a sponge between the support 93 and the separation pad 94, vibration of the separation pad 94 generated due to friction or the like at the time of document separation is absorbed. While increasing the pressure contact area with the paper feed roller 92, the pressure contact force per unit area is reduced to reduce the damage to the document while maintaining the document separation capability (for example, Patent Document 1 and Patent Document 1). Reference 2).
[0003]
[Patent Document 1]
JP-A-4-226228 [Patent Document 2]
Japanese Patent Application Laid-Open No. 2001-97585
[Problems to be solved by the invention]
In the conventional sheet feeding device having the separation mechanism 90, the support 93 is provided so as to be able to protrude and retract from an opening formed in the sheet feed tray, so that the separation pad 94 provided on the upper surface of the support 93 is provided. It is pressed against the paper feed roller 92 disposed above the paper feed tray. In such a conventional paper feed device, when the original is placed on the paper feed tray, the document is inserted along the paper feed tray. The leading edge of the document may come into contact with the separation pad 94 protruding from the opening to damage the separation pad 94 such as peeling or tearing.
[0005]
In addition, when a step occurs between the support 93 and the elastic member 95 due to an error during manufacturing or assembly, the step causes a step or bulge on the separation surface of the separation pad 94, and the paper There was also a risk of clogging.
[0006]
The present invention has been made in view of such a problem, and a sheet feeding device capable of preventing a separation pad from being damaged by contact of a sheet member and preventing paper jam due to a step between a support and an elastic member. The purpose is to provide.
[0007]
[Means for Solving the Problems]
The present invention provides a paper feed tray that supports a plurality of sheet members in a stacked state, a paper feed roller that feeds the sheet members on the paper feed tray to a conveyance path, and a support that can press against the roller surface of the paper feed roller. A sheet, comprising: a body; a separation pad attached to the support and pressed against a roller surface; and an elastically deformable elastic member interposed between the separation surface of the separation pad and the support. In the apparatus, the paper feed tray is fixed to the bottom surface, and the downstream end thereof is laid so as to be in pressure contact with the separation surface on the upstream side of the pressure contact portion between the separation pad and the paper feed roller. It is provided with a guide film for guiding the sheet member to the separation surface of the separation pad.
In the present invention, the upstream side and the downstream side refer to the upstream side and the downstream side in the direction in which the sheet member is supplied. In addition, the sheet member in the present sheet feeding device is a document or a recording sheet in a copying device or a facsimile device, and other than a so-called plain paper, for example, a sheet-like material other than paper such as a transparent film for an overhead projector. Including.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a sheet feeding device according to an embodiment of the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic perspective view showing an external appearance of an upper part of a copy / facsimile multifunction peripheral 1 including a paper feeder 100 according to an embodiment of the present invention. As shown in the figure, the copy / facsimile multifunction machine 1 includes a reading table 2 on which a platen glass on which a document to be read is placed is placed, and a document holding cover for pressing and fixing the document on the platen glass. 3 and an operation panel 4 for inputting the start of reading of a document and the like. Further, a main body 5 having a built-in image recording unit for recording an image on a recording sheet, a transmission unit for transmitting an image, and the like, and a recording sheet for recording the read image are supplied below the reading table 2. And a paper feed cassette 6. The sheet feeding device 100 described below is provided integrally with the ADF in the document holding cover 3 so as to continuously feed a document to a reading position on the platen glass.
The copy / facsimile multifunction peripheral 1 is an example of a device including the paper feeding device according to the present invention, and the operation panel 4 and the paper feeding cassette 6 may have an arbitrary configuration.
[0009]
FIG. 2 is a schematic sectional view showing a schematic configuration of a longitudinal section of the document pressing cover 3. As shown in the figure, the document holding cover 3 is provided with an ADF for continuously transporting the document to a reading position on the platen glass and discharging the document. The sheet feeding device 100 is a part of the ADF. The document fed into the transport path by the paper feeder 100 reaches the reading position P along the transport guide 60, and when passing through the reading position P, the image of the document is read by the reading unit 61. It is to be read.
[0010]
The conveyance path has a substantially U-shape that guides a document from the paper feed tray 101 to a reading position, and guides the document placed on the paper feed tray 101 to the reading position P while inverting the document downward, and further feeds the document. The paper is discharged to a paper discharge tray 63 below the tray 101. That is, the original placed on the paper feed tray 101 is read by the reading unit 61 with the upper surface of the paper feed tray 101 being the lower side, and the document is discharged with the read surface being the lower side. It is discharged to the tray 63. Therefore, the read original conveyed by the ADF is discharged to the discharge tray 63 in the order of the pages placed on the paper feed tray 101. In the transport path, a transport roller 62 for transporting the original is appropriately disposed. The transport roller 62 is rotated by a paper feed motor (not shown), and it is naturally possible to increase or decrease the number of transport rollers according to the shape and distance of the transport path.
[0011]
The reading unit 61 includes a light source 610 for irradiating light to a reading position, a reflecting mirror 611 for guiding reflected light R from a document in a predetermined direction, a condensing lens 612 for converging the reflected light R, and the converging light. And a charge-coupled device (Charge Couple Device, hereinafter referred to as “CCD”) 613 that converts the signal into an electric signal and outputs the signal. The reading unit 61 configured as described above scans an image of a document conveyed on the conveyance path at the reading position P, guides reflected light R from the document to the CCD 613, and forms an image. The image signal converted into an electric signal is subjected to analog / digital conversion, shading processing, and the like, and then recorded on recording paper by an image recording unit such as a printer, or transmitted by a transmission unit such as a CODEC.
[0012]
Although not shown in the drawing, a drive source such as a read sensor and a step motor, a gear and a timing belt for transmitting the drive, and the like are appropriately provided in the document holding cover 3. It is configured to be controlled by control means together with the reading unit 61 and the like. Further, the configuration of the ADF described above is merely an example, and the reading unit 61 may be used in combination with a flatbed scanner that moves horizontally below a platen glass on which a document is placed to read an image, or may use a CCD. It is also possible to use a so-called contact image sensor (hereinafter, referred to as "CIS") in place of the reading unit 61 of the reduction optical system used, and further, to place the CCD or CIS at a position opposed to the conveyance path. It is also possible to arrange both of them, or to provide a document return path in the transport path to read both sides of the document.
[0013]
As shown in FIGS. 2 and 3, the paper feeding device 100 includes a paper feeding tray 101 that holds a plurality of documents in a stacked state, a paper feeding roller 102 that feeds the documents to a transport path, and a paper feeding roller 102. A support 103 that can be pressed against the roller surface, a separation pad 104 attached to the support 103 and pressed against the roller surface, and a guide film 105 provided from the bottom surface of the paper feed tray 101 to the separation pad 104. It is provided with.
[0014]
As shown in the figure, the paper feed tray 101 is provided on the upper part of the document pressing cover 3 so as to be slightly inclined in the direction in which the documents are supplied, and carries a plurality of documents in a stacked state on the upper surface thereof. It has become. When the user places a document on the paper feed tray 101, the user places the document such that the leading edge of the document is aligned with the inclined lower end of the paper feed tray 101. On the other hand, the inclined lower end of the paper feed tray 101 has a shape in which the upper surface thereof is below the paper feed roller 102 and then curves upward toward the roller surface of the paper feed roller 102. And the angle and position at which the original placed on the sheet feed roller 102 abuts. In addition, the curved portion allows a plurality of documents placed on the paper feed tray 101 inclined in the direction of the transport path to be stored in a stacked state without flowing into the transport path, and the document is supplied. When the original is placed on the paper tray 101, as shown in FIG. 3, the leading end of each original is obliquely displaced along the curved portion. And double feed is prevented. Although not shown in the drawing, the paper feed tray 101 is provided with a variable guide member that regulates the position of the document in the width direction to prevent the document from being skewed.
[0015]
A paper feed roller 102 and a separation pad 104 are arranged near the inclined downstream side of the paper feed tray 101, respectively, and transport a plurality of documents placed on the paper feed tray 101 while separating them one by one. It is designed to run into the road.
[0016]
The paper feed roller 102 is disposed at an upper portion of the entrance of the conveyance path, and is configured to feed the original to the conveyance path by rotating while pressing against the original. For example, a silicon roller may be used. Further, on the upstream side of the paper feed roller 102, a pickup roller 20 for taking out the uppermost sheet of the original placed on the paper feed tray 101 is provided. Similarly to the paper feed roller 102, the pickup roller 20 also rotates the document while pressing it against the document to feed the document to the transport path. The swing arm 21 that swings up and down by a paper feed clutch (not shown). , And can be moved toward and away from the bottom surface of the sheet feeding tray 101. Due to the swing of the swing arm 21, the pickup roller 20 is separated from the paper feed tray 101 in a normal state such as when a document is placed on the paper feed tray 101. As the pickup roller 20 and the paper feed roller 102 rotate, the uppermost sheet of the document is fed into the transport path.
[0017]
Since the pickup roller 20 can be lowered until it comes into contact with the bottom surface of the paper feed tray 101, the pickup roller 20 can always contact the uppermost sheet even if the thickness of the bundle of documents changes depending on the number of documents. The paper feed roller 102 and the pickup roller 20 are rotated by a paper feed motor (not shown) via appropriate gears and the like. The image sensor is detected by the set sensor, and the image reading control unit controls the operations of the sheet feeding roller 102, the pickup roller 20, and the swing arm 21 based on the detection signal.
[0018]
On the other hand, below the paper feed roller 102, an opening 10 is provided in the paper feed tray 101, and a support 103 is provided so as to protrude from the opening 10 on the upper surface on which the separation pad 104 is attached. I have. The separation pad 104 is attached to the upper surface of the support 103 and is in pressure contact with the roller surface of the paper feed roller 102. Although not shown in detail in the drawing, the separation pad 104 does not need to be provided in the entire area in the axial direction of the paper feed roller 102, and is located at a portion where various types of documents having a minimum reading width to a maximum reading width pass in common. In this case, it is sufficient to provide a frictional force capable of separating the original. Further, a part including the opening 10 of the paper feed tray 101 is configured as a lid 12 that can be opened and closed, so that maintenance work such as replacement of the separation pad 104 is facilitated.
[0019]
As shown in FIG. 4, the support member 103 is provided with a horizontal shaft 30 protruding to both sides on the upstream side of the lower part thereof, and the shaft 30 is supported by a housing or the like of the document pressing cover 3. Then, the support 103 can be rotated. Further, a coil spring 64 for urging the support 103 is interposed between the rotation tip side of the support 103 and the housing or the like, and a spring receiving portion 31 to which the upper end of the coil spring 64 is fitted is supported. It protrudes from the lower surface of the body 103. On the other hand, at the upstream end and the downstream end of the upper surface of the support 103, an upstream positioning portion 32 or a downstream positioning portion 33 is formed, respectively, whereby the elastic member provided on the upper surface of the support 103 is formed. 35 are positioned in the document supply direction.
[0020]
The upstream positioning portion 32 is for positioning the upstream end of the elastic member 35 and protrudes upward from the upper surface of the support 103, and its protruding height is substantially equal to the thickness of the elastic member 35. Therefore, when the elastic member 35 is disposed on the upper surface of the support 103, the upper surface of the upstream positioning portion 32 and the upper surface of the elastic member 35 are substantially flush. The downstream positioning portion 33 is for positioning the downstream end of the elastic member 35, and protrudes upward from the upper surface of the support body 103 similarly to the upstream positioning portion 32. It is lower than the thickness of the member 35. This is so that when a conveying force obliquely downward acts on the leading end side of the document pressed against the paper feed roller 102 and the separation pad 104, both the elastic member 35 and the separation pad 104 are compressed according to the conveyance force. This is because the original can be smoothly supplied by being elastically deformed.
[0021]
The elastic member 35 is positioned by the upstream positioning section 32 and the downstream positioning section 33. The elastic member 35 can be elastically deformed, such as a sponge or a foamed synthetic resin. For example, a sponge that easily elastically deforms in accordance with the thickness of a fed document or the like is preferable. The planar shape is a rectangle similar to the upper surface of the support 103, and the thickness is appropriately set in consideration of the degree of elastic deformation due to the thickness of the document.
[0022]
Further, a protruding piece 36 protruding in the horizontal direction is formed on the downstream side of the lower part of the support 103. The projecting piece 36 is for restricting the support body 103 urged upward by the coil spring 64 from turning upward from a predetermined position, and as shown in FIG. The supporting member 103 is disposed so that the supporting member 103 can come into contact with the peripheral portion of the opening 10 of the sheet feeding tray 101, the housing of the document pressing cover 3, the transport guide 60, and the like.
[0023]
The separation pad 104 is a sheet having a coefficient of friction with respect to the document lower than the coefficient of friction of the paper feed roller 102 with respect to the document and higher than the coefficient of friction between the documents, and can be formed of, for example, urethane resin. As shown in FIG. 4, the separation pad 104 is attached to the upper surface of the elastic member 35 to form a separation surface 40, and the upstream end and the downstream end of the separation surface 40 are bent downward. Then, it is fixed on the side surface of the support body 103 by an adhesive, a tucker, an engagement claw, or the like.
[0024]
As shown in FIGS. 2 and 3, the support 103 is provided so as to be able to protrude and retract from the opening 10 of the paper feed tray 101, so that the separation pad 104 is pressed against the roller surface from below the paper feed roller 102. The document is rotatable downward in accordance with the thickness of the document passing through the pressing portion.
[0025]
As shown in FIG. 3, the guide film 105 is provided from the upstream side of the opening 10 of the paper feed tray 101 to the separation surface 40 of the separation pad 104. The guide film 105 has a moderate strength enough to guide several originals in a predetermined direction, and is a thin film capable of being elastically deformed by an external force exceeding a certain level, such as polyethylene terephthalate or polypropylene. And the like can be used. Further, it is preferable that the guide surface of the guide film 105, that is, the surface, is smooth so that the document can be smoothly guided, and has a low coefficient of friction with respect to the document.
[0026]
As will be described in more detail, the sheet feed tray 101 has a concave notch 11 having substantially the same width as the opening 10 on the upstream side of the opening 10. The concave notch 11 is formed such that when the guide film 105 is disposed on the bottom surface of the document guide 10, the guide surface of the guide film 105 is flush with the bottom surface of the paper feed tray 101. The depth of the recess is substantially equal to the thickness of the guide film 105. The planar shape of the concave portion 11 is a rectangle similar to the guide film 105, but its length (dimension in the document supply direction) is shorter than the guide film 105. Accordingly, the guide film 105 is disposed in the concave portion 11 and is adhesively fixed to the sheet feeding tray 101 on the bottom surface side, but the downstream end portion 50 projects from the concave portion 12 to the downstream side. And the downstream end 50 is not bonded and fixed to the paper feed tray 101, and the downstream end 50 is in pressure contact with the separation pad 104 at the opening 10 as shown in the figure. . By providing the guide film 105 in this manner, the document is prevented from being caught on the peripheral edge of the opening 10 of the paper feed tray 101, the joint portion of the document holding cover 3 with the housing, and the like. Also, the separation pad 104 at a location A corresponding to the upstream side surface of the support 103 and the separation surface 40 of the separation pad 40 at a location B corresponding to the joint between the upstream positioning portion 32 and the elastic member 35 of the support 103. To prevent the original fed to this location from coming into contact with the original.
[0027]
On the other hand, the downstream end 50 does not reach the pressure contact portion C between the separation pad 104 and the paper feed roller 102. This is for the purpose of exerting the action of the separation surface 40 of the separation pad 104, that is, the action of pressing against the multi-fed document and stopping the document by its frictional force. As a result, the downstream end 50 of the guide film 105 comes into pressure contact with the separation surface 40 of the separation pad 104 on the upstream side of the pressure contact portion C. Thus, the guide is accurately guided to the separation surface 40 of the separation pad 104.
[0028]
FIG. 5 shows an operation in which only the uppermost document is separated from a plurality of documents placed on the paper feed tray 101 by the paper feed roller 102 and the separation pad 104 and sent to the transport path. However, when the uppermost sheet of the original is sent to the feed roller 102 by the pickup roller 20, the lower original is also sent to the feed roller 102 following the uppermost sheet due to frictional force or static electricity of the paper. There is. For example, as shown in FIG. 5 (a), when the pickup roller 20 is pressed and rotated to feed the paper D1 accompanying the paper D1 to be fed, the leading ends of the papers D1 and D2 are Is guided to the guide film 105 and fed to the separation surface 40 of the separation pad 104 on the upstream side of the press contact portion C. Therefore, as described above, the leading ends of the papers D1 and D2 do not come into contact with the separation pad 104 at the point A corresponding to the upstream side surface of the support 103, and the upstream positioning portion 32 of the support 103 does not come into contact with the separation pad 104. Even if there is a step or bulge on the separation surface 40 of the separation pad 40 at the location B corresponding to the joint between the elastic member 35 and the elastic member 35, the paper D1 and D2 can smoothly contact the pressure contact portion C without contacting the location B. And no paper jam occurs.
[0029]
Thereafter, in the press contact portion C, the paper D1 presses against the roller surface of the paper feed roller 102, and the paper D2 presses against the separation surface 40 of the separation pad 104. The paper D1 is sent to the conveyance path by the rotation of the paper feed roller 102. At this time, the leading end of the paper D2 is brought into contact with the separation surface 40 of the separation pad 104 by the separation pad 104 having a friction coefficient larger than the frictional force between the papers. In the pressed state, it is stopped against the frictional force of paper and static electricity. As a result, as shown in FIG. 5B, the paper D1 alone is sent to the conveyance path through the separation surface 40. At this time, even if the paper D1 is pressed against the separation pad 104, the paper D1 Since the coefficient of friction of the paper 102 with the paper is larger than the separation pad 104, the paper D1 is fed into the conveyance path according to the rotation of the paper feed roller 102 without being stopped by the separation surface 40 of the separation pad 104.
[0030]
Further, although not shown in the drawing, when a bundle of a plurality of documents is placed on the paper feed tray 101, even if the user presses or strongly inserts the documents, the guide film 105 is supported by the support 103. Since the separation pad 104 at the location A corresponding to the side surface of the document is also covered, the leading end of the document does not contact the location A, and damage such as peeling or tearing of the separation pad 104 can be prevented.
[0031]
In the above-described embodiment, the copy / facsimile multifunction peripheral 1 in which the paper feeder 100 is integrally provided with the ADF in the document holding cover 3 has been described as an example. Naturally, the present invention can be applied to a paper feed cassette or a manual tray for supplying recording paper, or can be applied to other devices such as a scanner. The configuration of the paper feeding device 100 described in the present embodiment is an example of a specific configuration of the paper feeding device according to the present invention, and various changes can be made without departing from the gist of the present invention. For example, the upper and lower positions of the paper feed roller 102 and the pickup roller 20 and the separation pad 104 may be reversed so that the originals on the paper feed tray 101 are sequentially fed from the bottom sheet.
[0032]
【The invention's effect】
As described above, according to the sheet feeding device of the present invention, the sheet feeding tray that holds a plurality of sheet members in a stacked state, the sheet feeding roller that feeds the sheet members on the sheet feeding tray to the conveyance path, A support that can be pressed against the roller surface of the paper feed roller, a separation pad that is attached to the support and presses against the roller surface, and an elastic deformation interposed between the separation surface of the separation pad and the support And a downstream end portion of the sheet feeding device, which is fixed to a bottom surface of the sheet feeding tray and is in pressure contact with a separation surface upstream of a pressure contact portion between the separation pad and the sheet feeding roller. The guide film is laid so as to guide the sheet member on the paper feed tray to the separation surface of the separation pad, so that the sheet member does not come into contact with the separation pad when the sheet member is placed or supplied. Prevent the separation pad from being damaged That. Further, even if a step or the like occurs on the separation surface due to a step or the like between the support and the elastic member, it is possible to prevent the guide film from covering the step and prevent paper jam.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing an external appearance of a multi-function facsimile machine 1;
FIG. 2 is a schematic longitudinal sectional view showing an internal structure of a document pressing cover 3.
FIG. 3 is an enlarged vertical cross-sectional view showing a main configuration near a sheet feeding device 100.
FIG. 4 is a cross-sectional view illustrating a configuration of a support 103 and a separation pad 104.
FIG. 5 is a diagram illustrating a state in which a top sheet is separated from a plurality of documents by a sheet feeding device 100;
FIG. 6 is a schematic perspective view showing a main configuration of a conventional separation mechanism 90.
[Explanation of symbols]
REFERENCE SIGNS LIST 100 paper feeder 101 paper feed tray 102 paper feed roller 103 support 104 separation pad 105 guide film 35 elastic member 40 separation surface 50 downstream end

Claims (1)

A paper feed tray for carrying a plurality of sheet members in a stacked state, a paper feed roller for feeding the sheet members on the paper feed tray to a transport path, a support capable of pressing against the roller surface of the paper feed roller, In a paper feeding device including a separation pad attached to a support and pressed against a roller surface, and an elastically deformable elastic member provided between the separation surface of the separation pad and the support,
The sheet member on the sheet feed tray is fixed to the bottom surface of the sheet feed tray and laid so that the downstream end thereof is in pressure contact with the separation surface on the upstream side of the pressure contact portion between the separation pad and the sheet feed roller. A sheet feeding device comprising a guide film for guiding to a separation surface of a separation pad.

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