JP2005104609A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus capable of conveying a manuscript such that a platen glass is not contaminated as much as possible and generating no noise even if the hardly deflected manuscript is conveyed. <P>SOLUTION: In the copying/facsimile composite machine 1, notch parts 13a are arranged in a downstream end of a guide surface 13 constituting a lower guide surface in an upstream side of a reading position P with a predetermined gap in a width direction in parallel and conveying rollers 6 for conveying the manuscript to the reading position P are arranged at the notch parts 13a respectively. An elastic film 7 having the approximately same width as the guide surface 13 and formed with a cut out part 70 at a position corresponding to the respective conveying rollers 6 is stuck on a lower surface of a manuscript pressing cover body 10a so as to extend from the downstream side of the conveying roller 6 of the notch part 13a and the downstream end of the guide surface 13 to the just upstream of the reading position P. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus that reads an image by conveying a document on a document tray to a reading position through a conveyance path in a scanner, a facsimile, a copying machine, or the like.

  Some scanners, facsimiles, copiers, and the like are equipped with an image reading device such as an auto document feeder (hereinafter referred to as “ADF”) that sequentially feeds a plurality of documents. Accordingly, a plurality of documents placed on the document tray can be continuously and automatically conveyed to the reading position to perform image reading.

  FIG. 9 is a schematic perspective view showing the external appearance of a copy / facsimile multifunction peripheral 900 equipped with an ADF. As shown in FIG. 9, the copy / facsimile multifunction peripheral 900 has a platen glass on which a document to be read is placed. An installed reading table 901, a document pressing cover 902 that presses and fixes the document on the platen glass, an operation panel 903 for inputting reading start of the document, and an image for recording an image on a recording sheet A main body 904 including a recording unit, a transmission unit for transmitting images, and the like, and a paper feed cassette 905 for supplying recording paper for recording the read image are provided. In the copy / facsimile multifunction peripheral 900, the document on the document tray 906 is conveyed by an ADF in the document presser cover 902 so as to make a U-turn from the top to the bottom on a paper discharge tray 907 provided below the document tray 906. When the document passes through the reading position on the platen glass, the image of the original is read by the CCD provided in the reading table 901.

  FIG. 10 shows an example of the configuration of a conventional image reading apparatus. As shown in the drawing, a laterally U-shaped conveyance path 908 is formed from the document tray 906 through the reading position P to the paper discharge tray 907. . The conveyance path 908 is formed by a guide member 909 constituting an inner guide surface and a casing 910 of a document presser cover 902 constituting an outer guide surface. A conveyance roller 911 and the like are appropriately provided on the guide member 909 and the casing 910. It is arranged. The casing 910 is opened at the reading position P, and when a document conveyed through the conveyance path 908 passes through the opening, that is, the reading position P, an image is displayed by a CCD unit (not shown) via the platen glass 912. Read.

  In the conventional image reading apparatus as described above, when the document conveyed on the conveyance path 908 reaches the reading position P, the leading edge of the document guided by the guide surface of the casing 910 is the platen glass at the reading position P. Abutting on 912 and passing through the reading position P while sliding along the platen glass 912. As a result, paper powder or original toner adheres to the platen glass 912, causing a problem that the read image is deteriorated or disturbed. In addition, there is a problem that the leading edge of the document hits the joint between the upstream end of the platen glass 912 and the frame of the reading table 901, and noise is generated or the document is damaged.

  On the other hand, a pressing plate made of a thin stainless steel plate is projected from the guide surface of the casing 910 to the reading position P side to guide the conveyed document so as to come into contact with the inner guide member 909, so that the document is The structure which prevents contact | abutting to the platen glass 912 is devised (refer patent document 1). However, fixing materials such as screws are necessary to fix the presser plate, and the presser plate is rotated so that the original can be pressed against the guide member 909 while flexibly responding to the thickness of the original. Many other members are required, such as providing a fulcrum and pivotally supporting the casing 910 and energizing it with a coil spring, and it is also necessary to secure a space for attaching these members. On the other hand, if a resin elastic film is used as the press plate instead of the stainless press plate, the elastic film itself is elastically deformed in accordance with the thickness of the original, so that only the elastic film is attached to the casing 910. The same effect as described above can be realized with simple and space saving.

Japanese Utility Model Publication No. 7-42258

  As shown in FIG. 10, in the conventional image reading apparatus, a conveyance roller 911 is provided on the upstream side of the reading position P of the conveyance path 908 so as to convey the document in a nipped state. Yes. As shown in FIG. 11, the conveying roller 911 has a predetermined width of the conveying roller 911 aligned in the width direction at a predetermined interval so as to convey documents of various widths such as A4 size and B4 size. A notch 910a is formed in the guide member 910 in accordance with the position where the conveying roller 911 is disposed, and the roller surface of each conveying roller 911 is exposed. Further, in order to stabilize the conveyance of the document at the reading position P, it is preferable to nip the document by the conveyance roller 911 at a position as close as possible to the reading position P. Therefore, notches for disposing the respective conveyance rollers 911 are provided. 910a is formed near the reading position P. Therefore, there is no guide surface by the guide member 910 on the downstream side of the conveying roller 911. Therefore, when the elastic film 913 as described above is provided, as shown in the drawing, the elastic film 913 is attached to a portion other than the notch 910a, that is, a portion other than the downstream side of the conveying roller 911.

  However, when a thick document or a document that is difficult to bend is conveyed, the elastic film 913 may be greatly elastically deformed to the platen glass 912 side by the contact of the document. Further, since the speed at which the document is conveyed is increased, the impact when the document comes into contact is increased, and the elastic film 913 may be similarly elastically deformed. At that time, at the portion where the elastic film 913 is not attached, that is, at the downstream side of the conveying roller 911, the leading edge of the document collides with the upstream end of the platen glass 912 to generate noise, or the document is damaged by the collision. Problem occurs. In order to prevent such a problem, a film is separately attached so as to cover the joint between the upstream end of the platen glass 912 and the frame of the reading table 901. However, the platen glass 912 is periodically cleaned with a cloth or the like. Therefore, the film is often drowned at the time of cleaning, and another problem arises that the film must be frequently reapplied.

  The present invention has been made to solve such problems, and can convey a document so as not to contaminate the platen glass as much as possible, and generates abnormal noise even when a document that is difficult to bend is conveyed. An object of the present invention is to provide an image reading apparatus having no image.

  In the present invention, a document on a document tray is fed to a conveyance path by a paper feed roller disposed near the entrance of the conveyance path, conveyed to a reading position by a conveyance roller, and an image is read. In an image reading apparatus that discharges to a paper discharge tray by a paper discharge roller disposed, a notch is formed at a predetermined interval in the width direction at the downstream end of a guide member that forms a lower guide surface upstream of the reading position. Conveying rollers for conveying the document to the reading position are disposed in parallel in the cutout portions, and the cutout portions are formed at positions corresponding to the respective conveying rollers, which are substantially the same width as the guide member. An elastic film is affixed to the lower surface of the guide member so as to extend from the downstream side of the notch part to the downstream side of the conveying roller and from the downstream end of the guide member.

  According to the present invention, the cutout portion corresponding to each conveyance roller is formed in the elastic film so that it extends from the downstream end of the guide member provided with the conveyance roller and the downstream side of each conveyance roller. The elastic film covers the entire upstream end side of the platen glass when the elastic film is largely elastically deformed to the platen glass side due to the contact of the original with no part where the elastic film is stuck on the downstream side of the guide member. Therefore, the leading edge of the document does not come into contact with the upstream edge of the platen glass. As a result, the generation of abnormal noise during document conveyance is prevented, and the document is not damaged. Further, it is possible to prevent the original from sliding on the reading position of the platen glass and prevent the platen glass from being stained.

  FIG. 1 is a diagram showing a cross section of an upper part of a copy / facsimile multifunction peripheral 1 which is an image reading apparatus according to an embodiment of the present invention. As shown in the figure, the copy / facsimile multifunction peripheral 1 includes a document tray 2 that holds a plurality of documents in a stacked state, a laterally U-shaped transport path 3, and a transported document in a stacked state. A paper discharge tray 4 to be carried, a paper feed roller 5 for feeding a document on the document tray 2 to the conveyance path 3, a conveyance roller 6 for nipping and conveying the document in the conveyance path 3, and an upstream side of the reading position P The elastic film 7 is provided, a paper discharge roller 8 provided near the exit of the conveyance path 3, and a reading unit 9 that reads an image of a document at a reading position P. Although not shown in the figure, the copy / facsimile multifunction peripheral 1 has an operation panel for inputting start of reading of an original, an image recording unit for recording an image on recording paper, and transmission for transmitting an image. And a well-known configuration such as a paper feed cassette that supplies recording paper for recording the read image, and these well-known configurations are examples and arbitrary.

  In the copy / facsimile multifunction peripheral 1, the original fed from the original tray 2 to the conveyance path 3 is reversed so as to make a U-turn from the upper side to the lower side along the horizontal U-shaped conveyance path 3, and reaches the reading position P. When the document passes through the reading position P, the image of the document is read by the reading unit 9 and discharged to the paper discharge tray 4 below the document tray 2. The original transported by the copy / facsimile multifunction peripheral 1 is not only so-called plain paper of various sizes commonly used for copying and printers, but also has a thickness that can pass through the transport path and is placed in a lateral U-shaped transport path. It can be bent along.

  As shown in FIG. 2, the document tray 2 is provided on the upper part of the document pressing cover 10 so as to be slightly inclined in the direction in which the document is supplied, and supports a plurality of documents in a stacked state on the upper surface thereof. It has become. When the user places a document on the document tray 2, the document is placed so that the leading end of the document is inserted into the entrance of the conveyance path 3 on the inclined lower end side of the document tray 2. Although not shown in the figure, the document tray 2 is provided with a variable guide that regulates the position of the document in the width direction and prevents the document from being obliquely fed.

  The conveyance path 3 is formed in a lateral U shape from the document tray 2 to the paper discharge tray 4, passes through the platen glass 11 that becomes the reading position P immediately downstream of the folded portion, and is downstream of the reading position P. The side is inclined obliquely upward. In the transport path 3, a paper guide (guide member) 30 disposed in the document pressing cover 10 forms an inner guide surface, and a cover body (guide member) 10 a and the ADF cover 10 b of the document pressing cover 10 are outer guides. A surface is formed so that a document having a predetermined thickness can pass therethrough. The inner and outer guide members constituting the transport path 3 are not limited to the paper guide 30 and the cover main body 10a shown in the present embodiment, and other guide members may be used without departing from the scope of the present invention. Although it can take a form, it is preferable because the cover body 10a and the ADF cover 10b of the document presser cover 10 are integrally formed using a plastic material so that they also serve as an outer guide member, thereby reducing the number of parts and facilitating assembly. .

  As shown in FIG. 3, the paper feed roller 5, the transport roller 6, the paper discharge roller 8 (not shown) and the like are assembled to the paper guide 30, and a drive gear (not shown). ) And the like are assembled and disposed on the cover body 10a of the document presser cover 10. As shown in FIGS. 3 and 4, the cover main body 10 a has an opening 12 formed in the attachment portion of the paper guide 30, and the original conveyed along the paper guide 30 is platen glass 11 in the opening 12. The image passes through the upper reading position P and is read by the reading unit 9. The upstream side and the downstream side of the opening 12 are inclined upwardly from the opening 12 to become guide surfaces 13 and 14, respectively, and these guide surfaces 13 and 14 are turned portions of the lateral U-shaped conveyance path. An outer guide surface (lower guide surface) that is further downstream and upstream and downstream of the reading position P is configured. Three or two notches 13a and 14a are formed in the width direction at the downstream end of the guide surfaces 13 and 14, respectively, and the transport roller 6 or the discharge roller 8 is arranged in the notches 13a and 14a, respectively. It is set up. As described above, the guide surfaces 13 and 14 which are the lower guide surfaces upstream and downstream of the reading position P are integrally formed on the cover body 10a of the document cover 10, thereby attaching the guide member to the cover body 10a. Is eliminated, and the number of parts and the number of assembly steps are reduced. Although not shown in the drawing, the ADF cover 10b is disposed on the cover body 10a to which the paper guide 30 is assembled so as to be openable and closable. Note that paper feed ribs are appropriately formed on the guide surfaces 13 and 14 that are the inner guide surface and the outer guide surface formed by the paper guide 30 in order to reduce the frictional force with the document.

  As shown in FIG. 2, the paper feed roller 5 is arranged above the paper guide 30 and feeds the original into the conveyance path by rotating while being in pressure contact with the original fed from the original tray 2. For example, a roller made of silicon or EPDM (Ethylene-Propylene-Diethylene Methylene Linkage) is fixed to a metal roller shaft. Further, a pickup roller 50 for feeding the uppermost sheet of the document placed on the document tray 2 is disposed on the upstream side of the paper feed roller 5. The pick-up roller 50, like the paper feed roller 5, rotates while being in pressure contact with the original, thereby feeding the original into the transport path, and a swing arm that swings up and down by a paper supply clutch (not shown). 51 is supported. Due to the swing of the swing arm 51, the pickup roller 50 is separated from the paper guide 30 in a normal state such as when a document is placed on the document tray 2, and contacts the uppermost sheet of the document when the document is fed. When the pickup roller 50 and the paper feed roller 5 are rotated, the uppermost sheet of the original is fed into the conveyance path. Since the pickup roller 50 can be lowered until it contacts the paper guide 30, it can always contact the uppermost sheet even if the thickness of the bundle of documents changes depending on the number of documents. Although not shown in the drawing, the presence or absence of a document on the document tray 2 is detected by a document set sensor, and the control means operates the paper feed roller 5, the pickup roller 50, and the swing arm 51 based on the detection signal. It is intended to control.

  On the other hand, a separation pad 52 is provided below the paper feed roller 5. The separation pad 52 has a friction coefficient with respect to the document lower than that with respect to the document of the paper feed roller 5 and higher than the friction coefficient between documents, and can be formed of, for example, urethane resin. Such a separation pad 52 is stuck on the upper surface of the separation pad holder 53. The separation pad holder 53 is fitted on the upper surface of the paper guide 30 so as to be swingable and is biased upward by a coil spring 54, whereby the separation pad 52 is pressed against the roller surface of the paper feed roller 5. , And can be rotated downward in accordance with the thickness of the document passing through the pressure contact portion.

  As described above, the transport roller 6 and the paper discharge roller 8 are disposed on the paper guide 30 and the cover body 10a, respectively, and silicon or EPDM rollers are fixed to a metal roller shaft at predetermined intervals. The roller shaft rotates when a rotational force from a driving source such as a motor is transmitted to the roller shaft. The transport roller 6 and the paper discharge roller 8 are disposed in pressure contact with each other at positions opposite to the transport path 3, so that the document is nipped and transported and discharged in the transport path 3. Here, the conveyance roller 6 on the upstream side of the reading position P is disposed at a position as close as possible to the reading position P in order to stabilize the conveyance of the document at the reading position P. Depending on the shape and distance of the conveyance path, the conveyance roller 6 can be further arranged. The number and positions of the rollers to be fixed to one roller shaft are determined by the size of the document to be conveyed. Set in consideration.

  Moreover, as shown in FIG. 5, the elastic film 7 is stuck below the guide surface 13 of the said cover main body 10a. The elastic film 7 has a suitable strength that can guide the document being transported, and is a thin film that can be elastically deformed when the document being transported contacts, such as polypropylene or PET. It is a synthetic resin film. As shown in FIG. 6, the elastic film 7 has a rectangular shape with the same width as that of the guide surface 13 and the document, and the document corresponds to the notches 13 a formed at three locations on the guide surface 13. Cutout portions 70 are formed at three locations at predetermined intervals in the width direction. In the figure, a hatched area including the cutout portion 70 is a pasting margin 71 for pasting on the lower surface of the cover body 10a, and the remaining area is a projecting portion 72 projecting from the downstream end of the guide surface 13. is there. The pasting portion 71 is set in consideration of the fixing strength of the elastic film 7 and the space on the lower surface of the cover main body 10a, and the protrusion 72 has a length that does not reach the reading position P. For example, the reading position P It is set to extend several millimeters upstream. As shown in FIG. 5, the conveyance roller 6 on the upstream side of the reading position P is disposed in the vicinity of the downstream end of the guide surface 13 so as to be close to the reading position P, and is disposed in the notch 13a. There is no guide surface 13 on the downstream side of the transport roller 6, and a part of the transport roller 6 is also exposed from the lower surface of the cover body 10a. On the other hand, as shown in FIG. 7, the elastic film 7 is attached to the lower surface of the cover main body 10a so that the cutout portions 70 correspond to the positions of the respective transport rollers 6, so that the elastic film 7 can be removed from the lower surface of the cover main body 10a. Without interfering with the exposed conveying roller 6, the downstream side of the conveying roller 6 disposed in the notch 13 a and the downstream end of the guide surface 13 extend directly from the downstream end of the platen glass 11 to the reading position P. The elastic film 7 can be extended to the upstream. The elastic film 7 may be partially formed with a cutout or cutout for the lead sensor to detect the original.

  As shown in FIG. 1, the reading unit 9 is provided in a reading table 15, and a light source 90 for irradiating the reading position P with light and a reflected light R from the document in a predetermined direction. A reflection mirror 91, a condenser lens 92 that converges the reflected light R, and a charge coupled device (Charge Coupled Device, hereinafter referred to as “CCD”) 93 that converts the converged light into an electrical signal and outputs the electrical signal. This is a so-called reduction optical system CCD reading unit. The reading unit 9 configured as described above scans the image of the document conveyed on the conveyance path at the reading position P, and guides the reflected light R from the document to the CCD 93 to form an image. The image signal converted into an electrical signal is subjected to analog / digital conversion, shading processing, etc., and then recorded on a recording sheet by an image recording unit such as a printer, or transmitted by a transmission unit such as CODEC. Further, when the ADF is not used, the reading unit 9 is used as a reading unit of a flat bed scanner for scanning a document placed on the reading table 15.

  With the copy / facsimile multifunction peripheral 1 configured as described above, the document on the document tray 2 is sent to the transport path 3 by the paper feed roller 6, transported to the reading position P by the transport roller 6, and the document by the reading unit 9. The image is read and discharged to the paper discharge tray 4 by the paper discharge roller 8. Hereinafter, the operation of the document passing the reading position P will be described in detail.

  The documents fed from the document tray 2 by the pickup roller 50 and separated one by one by the paper feed roller 5 and the separation pad 9 are conveyed through the conveyance path 3 according to the rotation of the conveyance roller 6 while being nipped by the conveyance roller 6. Thus, the reading position P is reached. Here, if the original is easy to bend like plain paper, the original is read by being guided by the elastic film 7 and sliding on the guide surface of the paper guide 30 as shown in FIG. Since the original passes through the position P, the original does not come into contact with the reading position P of the platen glass 11, and paper dust or toner of the original does not adhere to the reading position P of the platen glass 11 and become dirty. Image deterioration can be prevented. Further, since the passage position of the original is regulated by the elastic film 7, the original is prevented from fluttering and loosening, and stable image reading can be performed. Note that, as described above, the elastic film 7 can be elastically deformed when the original comes into contact with it, and the original is not subjected to an excessive load. There will be no image distortion or paper jams.

  On the other hand, when the original is difficult to bend, the protrusion 72 of the elastic film 7 is greatly elastically deformed downward as a result of the leading edge of the original contacting the elastic film 7 as shown in FIG. However, as described above, the elastic film 7 extends not only from the downstream end of the guide surface 13 but also from the downstream side of the conveying roller 6 disposed in the notch 13a. 7 covers the entire joint between the upstream end of the platen glass 11 and the frame of the reading table 15, and the leading edge of the original does not collide with the upstream end of the platen glass 11, thereby preventing abnormal noise and damage to the original. .

  Note that the configuration of the copy / facsimile multifunction peripheral 1 shown in the present embodiment is only one aspect of the image reading apparatus according to the present invention, and it is needless to say that the design can be changed as appropriate without departing from the gist of the present invention. For example, it can be realized as a single machine such as a copying machine, a facsimile machine, or a scanner. Also, the reading unit 9 is not used in combination with a flatbed scanner, or a reduction optical system using a CCD is used. A so-called contact image sensor (hereinafter referred to as “CIS”) can be used in place of the reading unit, and a CCD or CIS is arranged at a position opposite to the conveyance path 3. It is also possible to appropriately change the path of the transport path 3 such as providing a document return path in the transport path 3 to read both sides of the document. is there.

  The image reading apparatus according to the present invention can be used as, for example, a scanner, a facsimile machine, a copying machine, or the like that automatically conveys a document from a document tray to a reading position, reads the image, and discharges it to a discharge tray.

1 is a cross-sectional view showing a configuration of an upper part of a copy / facsimile multifunction peripheral 1 according to the present embodiment. FIG. 4 is an enlarged cross-sectional view illustrating a configuration in the vicinity of a reading device P. 4 is an exploded perspective view showing the assembly of the document presser cover main body 10a and the paper guide 30. FIG. 3 is a plan view of a document presser cover main body 10a. FIG. 4 is an exploded perspective view showing a state where the guide surface 13 of the document presser cover main body 10a and the elastic film 7 are attached. FIG. 3 is a plan view showing a configuration of an elastic film 7. FIG. 4 is a plan view showing a state where the guide surface 13 of the document presser cover main body 10a and the elastic film 7 are attached. FIG. (A) is a figure which shows the state at the time of the document easy to bend passing the reading position P, (b) is a figure which shows the state at the time of the document which is hard to be bent pass the reading position P. FIG. 11 is a perspective view showing an appearance of a conventional copy / facsimile multifunction peripheral 900. FIG. 6 is an enlarged sectional view showing a sectional structure of a conventional copy / facsimile multifunction peripheral 900. It is a top view which shows the pasting state of the conventional elastic film 913.

Explanation of symbols

1 Copy / facsimile multifunction peripheral (image reading device)
2 Document tray 3 Transport path 4 Paper discharge tray 5 Paper feed roller 6 Transport roller 7 Elastic film 8 Paper discharge roller 9 Reading unit 10a Document press cover main body (guide member)
11 Platen glass 13 Guide surface (lower guide surface)
13a Notch part 70 Notch part

Claims (1)

The document on the document tray is fed to the conveyance path by a paper feed roller disposed near the entrance of the conveyance path, and is conveyed to a reading position by the conveyance roller to read an image, and is disposed near the exit of the conveyance path. In an image reading apparatus that discharges to a discharge tray by a discharge roller,
At the downstream end of the guide member that forms the lower guide surface upstream of the reading position, notches are arranged in parallel in the width direction at a predetermined interval, and the conveying roller that conveys the document to the reading position in the notches Are arranged on the downstream side of the notch portion and the downstream end of the guide member. The image reading apparatus is attached to the lower surface of the guide member so as to extend immediately upstream from the reading position.

Images