JP2007008679A - Paper delivering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper delivering device capable of corrugating a document to be delivered, while restricting rise of the manufacturing cost. <P>SOLUTION: This paper delivering device is provided with a lower guide part 121c provided with a guide surface 121d for guiding a document D to be delivered, a plurality of delivery rollers 128 provided on a guide surface 121d side of the lower guide part 121c with a space to deliver the document D guided by the guide surface 121d, and a paper delivery tray 13 to be loaded with the document D delivered by the paper delivery roller 128. The lower guide part 121c is provided with a plurality of projection parts 130 provided near the paper delivery roller 128 to project from a common contact surface P of the paper delivery roller 128 with the document D toward the center of the paper delivery roller 128 to make the document D partially project toward the center of the paper delivery roller 128. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a paper discharge device that is mounted on, for example, an automatic document feeder of an image forming apparatus and discharges taken sheets one by one to a paper discharge tray or the like.

  An image forming apparatus such as a copying machine may be equipped with an automatic document feeder (ADF). This automatic document feeder takes out documents (paper sheets) stacked on a paper feed tray one by one, feeds them to a reading position R of the image forming apparatus, and discharges them to a paper discharge tray after reading an image. . Therefore, the automatic document feeder is equipped with a paper discharge device for discharging the document after image reading to a paper discharge tray.

  The paper discharge device includes a guide member that guides a document and a paper discharge roller that discharges the guided document to a paper discharge tray.

  By the way, the conventional paper discharge device has a problem that the alignment of the originals on the paper discharge tray, that is, the paper discharge alignment, is deteriorated due to variations in the discharge speed and the document size. The main cause of the drop in the paper discharge alignment is that the leading edge of the discharged document hangs down due to gravity and touches the surface of the document that has already been discharged to the discharge tray, causing the document on the discharge tray to move. It is in.

  In order to solve this problem, a technique has been developed in which a corrugation is applied to a document to be ejected by providing a collar on one or both ends of the paper ejection roller. Since the original with corrugation is improved in straightness at the time of discharge, the position where the original discharged later first comes into contact with the original on the discharge tray is moved away. As a result, the time and area during which the document that is discharged later is in contact with the surface of the document on the discharge tray are reduced, and the discharge alignment of the documents is improved.

As a technique for corrugating a manuscript, a technique for discharging paper in a fixing device of an image forming apparatus is disclosed (for example, refer to Patent Documents 1 and 2). In these Patent Documents 1 and 2, the corrugation is applied to the manuscript by the collar provided on the roller corresponding to the paper discharge roller as described above.
JP-A-9-240900 JP 2002-12355 A

  However, there is a problem in that the manufacturing cost increases when the collar portion is provided on the paper discharge roller as in the prior art.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a paper discharge device capable of corrugating discharged paper sheets without increasing manufacturing costs. There is.

  In order to solve the above problems and achieve the object, a paper discharge device according to the present invention includes a guide member having a guide surface for guiding a paper sheet to be conveyed, and a paper sheet on the guide surface side of the guide member. And a plurality of paper discharge rollers for discharging the paper sheets guided by the guide surface, and a paper stack for stacking the paper sheets discharged by the paper discharge rollers. A paper tray, and the guide member is provided in the vicinity of the paper discharge roller and protrudes toward the center of the paper discharge roller from a tangential plane between the paper discharge roller and the paper sheet, and the paper sheet A plurality of protrusions are provided to partially protrude the portion toward the center side of the paper discharge roller.

  According to the present invention, it is possible to corrugate discharged paper sheets without increasing manufacturing costs.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
(Configuration of digital copier)
FIG. 1 is a front view showing a digital copying machine according to an embodiment of the present invention. As shown in FIG. 1, the digital copying machine includes an automatic document feeder (ADF; auto document feeder) 10, a scanner unit 20, and a printer engine unit 30.

  The automatic document feeder 10 takes in documents (paper sheets) D one by one and supplies them to a predetermined reading position R (described later).

  The scanner unit 20 optically reads an image of the document D supplied by the automatic document feeder 10 or manually placed, and converts it into image data.

  The printer engine unit 30 includes a charging charger, a laser unit, a photosensitive drum, a developing device, a transfer roller, and a fixing device (all not shown). The charging charger charges the surface of the photosensitive drum to a predetermined potential. The laser unit forms an electrostatic latent image on the surface of the photosensitive drum based on the image data from the scanner unit 20. The developing device develops the electrostatic latent image on the photosensitive drum with toner. The transfer roller transfers the toner image formed on the photosensitive drum to a sheet. The fixing device fixes the toner image transferred to the paper. With such a configuration, the document image read by the scanner unit 20 is copied onto a sheet by the printer engine unit 30.

(Configuration of automatic document feeder 10)
FIG. 2 is a cross-sectional view showing an internal configuration of the automatic document feeder 10 according to the embodiment. As shown in FIG. 2, the automatic document feeder 10 takes a document tray 11 on which a plurality of documents D are placed, removes the document D from the sheet feed tray 11, and follows a conveyance path C (described later). And a paper discharge tray 13 in which a plurality of originals D discharged from the transport device 12 are accommodated.

  The transport device 12 includes first and second guide members 121 and 122. Each of the first and second guide members 121 and 122 has a smooth guide surface inside, and a conveyance path C for conveying the document D is provided in a gap between the guide surface and the guide surface. Yes.

  The transport path C has a U-shape that connects the paper feed tray 11 and the paper discharge tray 13, and a reading position R for reading a document image is provided at a portion closest to the scanner unit 20. It has been.

  The first guide member 121 is disposed outside the second guide member 122, and a rectangular opening 121a is formed at the reading position R thereof. As a result, the document D transported on the transport path C faces the scanner unit 20 when passing the reading position R.

  In the conveyance path C, the pickup roller 123, the separation roller 124, the first conveyance roller 125a, the registration roller 126, the second conveyance roller 125b, the stabilization roller 127, the third roller are sequentially arranged from the upstream side in the conveyance direction of the document D. A roller 125c and a paper discharge roller 128 are disposed.

  The pickup roller 123 picks up the documents D one by one from the paper feed tray 11 and takes them into the transport path C of the transport device 12. The separation roller 124 allows only the uppermost document D to pass through when the plurality of documents D are taken in by the pickup roller 123 and blocks the progress of the remaining documents D. The first to third transport rollers 125 a to 125 c transport the document D separated by the separation roller 124 along the transport path C. The registration roller 126 aligns the document D conveyed by the first to third conveyance rollers 125a to 125c. The stability roller 127 stabilizes the behavior of the document D conveyed by the first to third conveyance rollers 125a to 125c immediately before the reading position R. The paper discharge roller 128 discharges the original D conveyed by the first to third conveyance rollers 125 a to 125 c from the conveyance path C of the conveyance device 12.

  Note that a plurality of these rollers 123 to 128 are provided on a horizontally supported drive shaft at a predetermined interval, and in this embodiment, four each are provided. When each drive shaft rotates, the rollers are provided on the drive shaft. All the rollers 123 to 128 rotate at the same time.

  Further, a pinch roller 129 is disposed immediately below the paper discharge roller 128. The pinch roller 129 is rotatably disposed in a groove portion 121b (shown only in FIGS. 3 and 4) of the first guide member 121 (lower guide portion 121c described later), and elastic means such as a leaf spring. Is pressed against the outer peripheral surface of the paper discharge roller 128.

  By the way, the first guide member 121 is located below the second guide member 122 downstream of the reading position R. Therefore, a portion of the first guide member 121 on the downstream side of the reading position R is referred to as a lower guide portion 121c, and a portion of the second guide member 122 on the downstream side of the reading position R is referred to as an upper guide portion 122c.

  FIG. 3 is a schematic diagram illustrating the paper discharge unit 120 according to the embodiment from the front side, and FIG. 4 is a schematic diagram illustrating the paper discharge unit 120 according to the embodiment from the downstream side in the document conveyance direction.

  As shown in FIGS. 3 and 4, the lower guide portion (guide member) 121 c is disposed such that its guide surface 121 d is lower than the lowermost portion of the paper discharge roller 128, and is almost directly below the drive shaft of the paper discharge roller 128. Are provided with a plurality of projecting portions 130 in the present embodiment, which is an important point of the present invention. Note that the number of the protrusions 130 is not particularly limited.

  These projections 130 are arranged one by one so as not to face the paper discharge roller 128, in this embodiment, among the four paper discharge rollers 128 so as to sandwich the paper discharge roller 128 located on the outermost side from both sides. Each upper end protrudes upward from the lowermost part of the paper discharge roller 128.

  Each protrusion 130 includes a first inclined surface 130a that increases as it goes downstream in the conveyance direction on the side surface on the upstream side in the conveyance direction of the document D, and increases on the upper surface as it goes downstream in the conveyance direction. In addition, a second inclined surface 130b that is gentler than the first inclined surface 130a is provided.

  As a result, when the document D to be transported reaches the protrusion 130, the portion of the document D corresponding to the protrusion 130 is scooped up by the first inclined surface 130a, and reaches the second inclined surface 130b. On the other hand, the portion corresponding to the paper discharge roller 128 is guided as it is by the upper and lower guide portions 121c and 122c and enters between the paper discharge roller 128 and the pinch roller 129.

  As described above, in the present embodiment, the document D for which the document image has been read is guided by the lower guide portion 121 c and discharged to the discharge tray 13 by the discharge roller 128. Therefore, the lower guide portion 121c (including the protruding portion 130), the paper discharge roller 128, and the paper discharge tray 13 are a paper discharge portion (paper discharge device) for discharging the document D from the conveyance path C of the conveyance device 12. 120 is configured. In the present embodiment, the common contact surface P between the paper discharge roller 128 and the pinch roller 129 corresponds to the contact plane between the paper discharge roller and the paper sheet in the present invention.

(Configuration of the scanner unit 20)
The scanner unit 20 includes a glass plate (not shown) at a position corresponding to the reading position R. This glass plate is colorless and transparent, and a reading device (not shown) is provided on the scanner unit 20 side. This reading apparatus includes a first carriage, a second carriage, an imaging lens, and a CCD sensor (all not shown).

  The first carriage is provided with an exposure lamp (not shown) for irradiating light to the document D passing over the surface of the glass plate. The first and second carriages are provided with first to third mirrors (not shown) that reflect light reflected from the document surface in a predetermined direction.

  The light emitted from the exposure lamp when the document D passes the reading position R reaches the document surface through the glass plate. Then, the reflected light on the document surface returns to the scanner unit 20 through the glass plate, is reflected by the first to third mirrors, and is guided to the imaging lens. The light converged by the imaging lens is detected by the CCD sensor and used for creating image data.

  Further, on the upper surface of the scanner unit 20, there is provided a document glass table (not shown) that is used when reading a document image without using the automatic document feeder 10 and on which the document D is placed manually. Yes.

(Delivery operation of document D)
The document D, for which the document image has been read, is conveyed toward the paper discharge roller 128 while being guided by the upper and lower guide portions 121c and 122c. When the conveyed document D reaches the protruding portion 130 of the lower guide portion 121c, the portion corresponding to the protruding portion 130 of the document D is scooped up by the first inclined surface 130a and the second inclined surface. Get on 130b. On the other hand, the portion of the document D corresponding to the paper discharge roller 128 is directly guided by the guide surfaces 121d and 122d of the upper and lower guide portions 121c and 122c and enters between the paper discharge roller 128 and the pinch roller 129.

  As a result, the document D discharged to the paper discharge tray 13 has a portion corresponding to the protrusion 130 and the paper discharge roller 128 as shown by the one-dot chain line (A) and two-dot chain line (B) in FIG. A difference occurs in the direction of travel between the parts corresponding to.

  As a result, the document D discharged to the paper discharge tray 13 is provided with so-called corrugation in which the cross-sectional shape is locally substantially S-shaped. The documents D with corrugation are stacked one after another on the paper discharge tray 13.

  3 indicates the traveling direction of the portion corresponding to the protrusion 130 of the document D, and the two-dot chain line (B) of FIG. 3 indicates a portion corresponding to the paper discharge roller 128 of the document D. Indicates the direction of travel.

  It should be noted that the document once on the protrusion 130 contacts only the second inclined surface 130b until it is discharged to the discharge tray 13. That is, the first inclined surface 130a is used only for scooping up the leading end of the document D when the leading end of the document D reaches the protrusion 130.

(Comparison of output alignment)
[Table 1] shows a conventional embodiment in which corrugation is applied by the automatic document feeder 10 according to the present embodiment and a collar provided on the paper discharge roller with respect to variations in the transport direction of the original D discharged to the paper discharge tray 13. FIG. 2 shows a result of comparison with the automatic document feeder according to the present embodiment regarding variations in the horizontal direction of the document D discharged to the sheet discharge tray 13, that is, the direction perpendicular to the transport direction. This is a result of comparison between the automatic document feeder 10 and an automatic document feeder according to a conventional embodiment in which corrugation is performed by a collar provided on the paper discharge roller.

Each numerical value in [Table 1] and [Table 2] expresses the degree of variation of the document D. The larger the value, the larger the variation, and the smaller the value, the smaller the variation. Further, the conveyance speed of the document D in this comparison is about 210 mm / sec.

  As shown in [Table 1], in the automatic document feeder 10 according to the present embodiment, the document D is discharged compared to the automatic document feeder according to the conventional embodiment in which corrugation is provided by a collar provided on the paper discharge roller. It can be seen that the paper alignment is far superior.

  As shown in [Table 2], in the automatic document feeder 10 according to the present embodiment, the automatic document feeder according to the conventional embodiment in which corrugation is applied to almost any type of document by a collar provided on the paper discharge roller. It can be seen that far more excellent document D alignment of the document D can be obtained.

  [Table 3] is a result of comparing variations in the conveyance direction of the document D discharged from the automatic document feeder 10 according to the present embodiment to the sheet discharge tray 13 by changing the type of the document D. [Table 4] ] Is a result of comparing variations in the horizontal direction of the document D discharged from the automatic document feeder 10 according to the present embodiment to the paper discharge tray 13, that is, in the direction orthogonal to the conveyance direction, by changing the type of the document D. is there.

Each numerical value in [Table 3] and [Table 4] expresses the degree of variation of the document D. The larger the value, the larger the variation, and the smaller the value, the smaller the variation.

  As shown in [Table 3] and [Table 4], it can be seen that although there is a slight difference in variation depending on the weight of the document D, it is generally within a narrow range.

  From the above results, when the automatic document feeder 10 according to the present embodiment is used, the document D is ejected as compared with the automatic document feeder according to the conventional embodiment in which corrugation is provided by the collar provided on the ejection roller. It was confirmed that the alignment was greatly improved.

(Operation by this embodiment)
The lower guide portion 121 c according to the present embodiment includes a plurality of protrusions 130 that protrude upward from the lowermost portion of the paper discharge roller 128. Therefore, since the so-called corrugation in which the cross-sectional shape is S-shaped is applied to the original D discharged to the paper discharge tray 13, the straightness of the discharged original D is improved.

  As a result, since the friction time and the contact area between the document D to be discharged later and the document D already loaded on the discharge tray 13 are reduced, the document D on the discharge tray 13 becomes difficult to move and is discharged. The paper discharge alignment property of the original D on the paper tray 13 is improved.

  In addition, the protrusion 130 according to the present embodiment is provided on the lower guide 121c. For this reason, the manufacturing cost is drastically reduced as compared with the conventional case where a collar portion is provided at one or both ends of the paper discharge roller 128.

  Furthermore, each protrusion 130 includes a smooth first inclined surface 130a that increases on the side surface on the upstream side in the conveyance direction of the document D, and becomes higher as it goes downstream in the conveyance direction. For this reason, since the burden on the document D can be reduced when the document D rides on the protrusion 130, occurrence of a situation in which the document D is damaged is suppressed.

  Further, the lower guide portion 121c is disposed such that the guide surface 121d is lower than the lowermost portion of the paper discharge roller 128. Therefore, the portion corresponding to the protruding portion 130 of the document D to be discharged rises more greatly when it rides on the protruding portion 130, so that a large corrugation is applied to the document D.

  Further, when the automatic document feeder 10 according to the present embodiment is used, the large document D can be discharged and aligned as compared with the automatic document feeder according to the conventional embodiment in which corrugation is provided by the collar provided on the discharge roller. Is obtained.

  The application target of the paper discharge unit 120 of the present invention is not limited to the automatic document feeder 10, and may be, for example, a paper discharge unit of a fixing device.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

1 is a front view showing a digital copying machine according to an embodiment of the present invention. Sectional drawing which shows the internal structure of the automatic document feeder based on the embodiment. Schematic which shows the paper discharge part which concerns on the same embodiment from the front side. FIG. 3 is a schematic diagram illustrating a paper discharge unit according to the embodiment from the downstream side in the document conveyance direction.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 13 ... Paper discharge tray, 120 ... Paper discharge part (paper discharge apparatus), 121d ... Guide surface, 129 ... Paper discharge roller, 121c ... Lower guide part (guide member), 133 ... Projection part, D ... Document (paper sheets) ), P ... Common tangent surface (tangential plane).

Claims (1)

A guide member having a guide surface for guiding the conveyed paper sheet;
A plurality of paper discharge rollers provided on the guide surface side of the guide member at intervals in a direction intersecting the paper sheet conveyance direction and discharging paper sheets guided by the guide surface;
A paper discharge tray for stacking paper sheets discharged by the paper discharge roller,
In the guide member,
It is provided in the vicinity of the paper discharge roller, protrudes from the contact plane between the paper discharge roller and the paper sheet to the center side of the paper discharge roller, and partially ejects the paper sheet to the center side of the paper discharge roller. A paper discharge device comprising a plurality of projecting portions that project from the paper.

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