JP4300992B2 - Paper feeding device and image reading device - Google Patents

Description

  The present invention relates to a paper feeding device and an image reading device that feed out paper or the like and feed out and read a document.

  When digitizing a large amount of originals, a paper feeding device that separates the originals one by one and conveys them to a portion that performs predetermined processing, such as an image reading unit, for example, an image reading device equipped with an ADF (auto document feeder) Is used. In recent years, these image reading devices have been increasing in number of multifunction peripherals that also serve as copiers such as digital copiers. However, due to the remarkable improvement in performance of personal computers (hereinafter referred to as PCs), image reading operations can be performed even on personal desks. The tendency of distributed processing is remarkable. In view of such a demand for distributed processing, many image scanners with ADF (hereinafter referred to as ADF scanners) that do not take up a large space even on a personal desk have been proposed (see, for example, Patent Document 1).

  Here, FIG. 5 is a general structural diagram of an image reading apparatus provided with a conventional document conveying mechanism.

  Above the image reading device 23, a hopper 100 for stacking the originals 107 is provided, the paper feed rollers 101 for picking up the stacked originals 107 and feeding them one by one to the original conveying path 110, and the downstream side in the conveying direction Are provided with a separation roller 102 and a retard roller 103 for preventing double feeding in which two or more sheets are fed out by friction between overlapping documents.

  Further, downstream of the separation roller 102 and the retard roller 103, a plurality of transport rollers 106a and 106b and platen rollers 105a and 105b are arranged, and the original 107 is passed through the reading units 104a (front side reading) and 104b (back side reading). Then, the original 107 is discharged out of the apparatus.

That is, in the ADF scanner with a small installation space as described above, in order to reduce the arrangement area of the apparatus, the document transport path 110 (hereinafter referred to as document path) is laid out in the height direction from the upper rear to the lower front, In general, the reading units 104a and 104b are arranged on both sides of the path 110, and the circuit unit 109 is arranged on the bottom surface, the back surface, or the left and right side surfaces.
Japanese Patent No. 3289767 (page 2-3, FIG. 1)

  However, in the ADF scanner having the document path 110 arranged in the height direction as shown in FIG. 5, the paper feed hopper 100 on which the document 107 is inevitably placed must be arranged in a direction substantially coinciding with the document path 110. Therefore, it is necessary to set the document on the document hopper 100 at the upper rear side of the apparatus every time reading is performed, and there is a problem that it is difficult to easily read the document between busy tasks. In addition, due to the progress of distributed processing, such a small installation space type ADF scanner is often used for window work, and in particular, a document with a bad state such as a document with a broken corner or a torn slip is read. In some cases, paper feeding problems often occurred. Furthermore, in such distributed processing, rather than reading a large amount of documents at once, it is often used for input processing of a small number of sheets, such as reading a small amount of documents or forms that occur irregularly each time. As the number of times increases, there is a strong demand for simplification of document setting work.

  In addition, when placing originals upright, in the case of so-called weak paper such as originals with a thin paper thickness, the originals often buckle due to their own weight, which may cause an obstacle to stable paper separation operation. In addition to saving space, there has been a demand for simplification of setting a small number of documents on a document hopper and stabilization of a thin paper thickness document feeding operation.

  In order to solve the above problems, the present invention is provided with a paper feed roller for feeding paper, a lower side of the paper feed roller, and downstream of the paper feed direction, and is driven to rotate in the paper feed direction. In a sheet feeding device having a separation roller and a retard roller that is pressed against and urged by the separation roller and is rotatable at a predetermined torque or more, the support roller is rotatably supported and is urged by a predetermined pressure. A sheet feeding driven roller, and a sheet feeding port or a sheet feeding guide path for inserting a sheet at a nip position between the sheet feeding driven roller and the retard roller are provided.

  With this configuration, it is possible to easily insert a document into a document hopper from the top of the main unit even with a small installation area, and to prevent buckling of thin paper documents due to weakness of the paper. Stable feeding.

  As described above, according to the present invention, the paper feed roller that feeds the paper, the lower side of the paper feed roller, and the downstream side of the paper feed direction, is driven to rotate in the paper feed direction. In a paper feeding device having a separation roller and a retard roller that is pressed against and urged against the separation roller and is rotatable at a predetermined torque or more, the paper is fed rotatably and biased to the retard roller with a predetermined pressure. The ADF scanner has a driven roller, and a paper feed port or a paper feed guide path for inserting paper at the nip position between the paper feed driven roller and the retard roller. When scanning about one sheet, it is possible to easily insert a document from another direction without setting it in the document hopper above the device. Do It can document under its own weight even if a weak sheet such as a so-called waist buckled stably thin paper thickness of a document that can not paper separation operation was to enable a stable paper feeding.

  According to the first aspect of the present invention, a paper feed roller that feeds paper, a lower side of the paper feed roller, and downstream of the paper feed direction, is driven to rotate in the paper feed direction. In a paper feeding device having a separation roller and a retard roller that is pressed against and urged by the separation roller and is rotatable at a predetermined torque or more, the feed roller that is rotatably supported and urged by the predetermined pressure to the retard roller. This is a paper feeding device provided with a paper driven roller and a paper feeding port or a paper feeding guide path for inserting paper at the nip position between the paper driven roller and the retard roller, and also in a paper feeding conveyance path configured in the height direction. Since paper can be read from another direction of the main body of the machine, it is possible to feed the paper more easily than in the other direction of the main body, saving the trouble of setting the paper in the upper hopper. Has the effect of being able to .

  According to a second aspect of the present invention, in the invention according to the first aspect, the sheet feed driven roller is configured such that the nip position between the sheet feed driven roller and the retard roller is greater than the nip position between the separation roller and the retard roller. Since the paper is arranged on the upstream side in the rotation direction, the sheet is inserted from the lateral direction of the main body of the apparatus without setting the paper in the upper hopper each time when reading several sheets. As a result, even if the paper is weak, the paper can be inserted and read from the lateral direction to prevent the digging due to its own weight and to perform a stable paper feeding operation.

According to a third aspect of the present invention, in the first aspect of the invention, the outer periphery of the retard roller that guides the sheet from the nip position between the paper feed driven roller and the retard roller to the nip position between the separation roller and the retard roller. And having a guide member rotatable around an axis provided in the vicinity of the paper feed driven roller, and the guide member, when the paper enters from the nip position of the paper feed driven roller and the retard roller, When a conveyance space with a predetermined width is formed between the guide member and the circumference of the retard roller, and the sheet enters from the direction of the sheet feed roller, the leading end of the guide member moves to the axis side of the retard roller. Each time, it saves the trouble of setting the paper in the upper hopper and reading it, and can easily feed the paper from the other direction of the main body of the device. It has an effect of reliably be 般送 along the de.

  According to a fourth aspect of the present invention, a paper feed roller that feeds a document, a lower side of the paper feed roller, and a downstream side of the document feed direction are driven to rotate in the document feed direction. An image reading unit having a separation roller, a retard roller that is pressed against the separation roller and is rotatable at a predetermined torque or more, and a reading unit that reads a document provided downstream of the separation roller in the document feeding direction. In the apparatus, a paper feed driven roller that is rotatably supported and urged by a predetermined pressure to the retard roller, and a paper feed port or a paper feed guide path for inserting paper into a nip position between the paper feed driven roller and the retard roller are provided. In the image input apparatus provided, it is possible to insert and read a document from another direction of the apparatus main body even in the paper feed conveyance path configured in the height direction. Set to It eliminates the need to read, with the effect that the document easily than another direction of the apparatus main body can feed.

  According to a fifth aspect of the present invention, in the invention according to the fourth aspect, in the paper feed driven roller, the nip position between the paper feed driven roller and the retard roller is on the circumference on the upstream side in the rotation direction of the retard roller. In this case, it is possible to insert a document from the lateral direction of the main body of the apparatus without setting the document in the upper hopper each time. Even if the document is weak, inserting and reading the document from the lateral direction prevents the digging due to its own weight and has a function of performing a stable paper feeding operation.

  According to a sixth aspect of the present invention, in the invention according to the fourth aspect, the outer circumference of the retard roller that guides the document from the nip position between the feed driven roller and the retard roller to the nip position between the separation roller and the retard roller. And having a guide member that is rotatable around an axis provided in the vicinity of the paper feed driven roller, and the guide member is used when the document enters from the nip position of the paper feed driven roller and the retard roller. When a conveyance space with a predetermined width is formed between the guide member and the circumference of the retard roller, and the document enters from the direction of the paper feed roller, the leading end of the guide member moves toward the axis of the retard roller. Each time, it saves the trouble of setting the document in the upper hopper and reading it, so that the document can be fed easily from the other direction of the device body and the document inserted from the other direction of the device body is guided. Has the effect of being reliably conveyed along.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a configuration diagram showing an image reading apparatus provided with a paper feeding device according to an embodiment of the present invention, and FIG. 2A is an enlarged view showing a paper feeding method of the paper feeding device provided in the image reading device of FIG. 2B is an enlarged explanatory view showing another paper feeding method of the paper feeding device provided in the image reading device of FIG. 1, and FIG. 3A is a document that the paper feeding device of FIG. 2A has. FIG. 3B is an enlarged cross-sectional view of the document guide switching device of FIG. 2A, and FIG. 4A is the paper feeding device of FIG. 2B. FIG. 4B is an enlarged cross-sectional view of the document guide switching device of FIG. 2B, and FIG. 5 is an explanatory diagram showing a general structural diagram of a conventional image reading device. Indicates.

First, the configuration of the paper feed mechanism of the image reading apparatus according to the embodiment of the present invention will be described with reference to FIG. An upper document hopper 6 for setting a large amount of documents 14 is disposed on the upper portion of the reading device main body 23. The document 14 set in the upper document hopper 6 is pressed against the sheet feed roller 1 by the document presser 13 that rotates in the direction of the arrow K about the axis when feeding, and the sheet feed roller 1 is moved in the direction of the arrow A. And the document 14 is fed into the nip portion between the separation roller 2 and the retard roller 3. Thereafter, the separation roller 2 rotates in the direction of arrow A, whereby the document 14 is further conveyed downstream in the conveyance path. The retard roller 3 is rotatably supported at a predetermined load torque around a shaft 21 fixed so as not to rotate on a retard roller holding plate 20 that is pivotally supported about a support shaft 19. The spring is not elastically pressed against the separation roller 2 with a predetermined pressure. 3 (a) and 4 (a), the paper feed driven roller 4 is rotatably supported by a spring 4a on a support shaft 22 slidable with a predetermined movement amount in the directions of arrows C and D. Then, it is repressed by the retard roller 3. This retard roller 3 receives the rotational torque of the separation roller 2 and rotates in the direction of arrow A, which is the conveyance direction of the paper 14, when the single paper 14 is fed from the paper feed roller 1, and the paper 14 is rotated. When the two sheets are conveyed in a superimposed manner and reach the nip position N, the retard roller 3 prevents the double-fed paper 14 from being conveyed downstream in the conveyance path.

  Next, a guide member (hereinafter referred to as a document guide 5) for switching a conveyance path of documents and the like will be described with reference to FIGS. The document guide 5 is pivotally supported on a support shaft 22 shown in FIGS. 3 and 4, and the document guide 5 is rotated in a predetermined direction by a document guide switching device 50 provided at an end of the support shaft 22. In this way, the transport path is switched. Here, the document guide switching device 50 (shown in FIGS. 3B and 4B) that switches the document guide 5 in the respective transport path directions is as shown in FIGS. 3A and 4A. , A cam 50c fixed to the end of the support shaft 22, and a lock plate spring 50b. The lock plate spring 50b is connected to a slide switch in one of a plurality of recesses formed in the cam 50c. It arrange | positions so that it may engage according to the conveyance path selected by 50a.

  More specifically, as shown in FIGS. 3 (b) and 4 (b), the protrusion 50d is fitted in a slide switch side recess 50e formed in the slide switch 50a so as to be swingable. Then, by moving the slide switch 50a in the arrow Y direction or the arrow Z direction according to the conveyance path, the cam side recess 50g (feeding position from the upper document hopper 6) and the cam side recess 50f ( The lock leaf spring 50b is engaged with either one of the paper feeding positions from the front document hopper 7 and the conveyance path is switched. That is, when the document 14 is fed from the upper document hopper 6 of the reading device 23 body, the leading end of the document guide 5 moves in the direction of arrow F shown in FIG. When the document 15 is fed from the feed port 18 of the front document hopper 7, the leading end of the document guide 5 moves in the direction of arrow E shown in FIG. 2B, and the document transport path is switched.

  In addition to the method described in the above embodiment, the conveyance path switching method is linked to the front document hopper 7 when the front document hopper 7 also serving as the exterior of the apparatus main body is pulled in the direction of arrow L (shown in FIG. 1). And you may switch so that it may become a conveyance path from the insertion port 18 ahead of an apparatus main body to the inside of an apparatus.

  Next, a paper feeding operation when a document is set on the upper document hopper 6 of the apparatus main body 23 will be described in detail with reference to FIGS. First, when the slide switch 50a of the document guide switching device 50 in FIG. 3A is moved in the direction of arrow Y and the document guide 5 is switched in the direction of arrow F shown in FIG. Is formed.

When the document 14 is set on the upper document hopper 6 in FIG. 1 and a reading command is given from the PC to the scanner, the document presser 13 rotates in the direction of arrow K and presses the bundle of documents 14 against the paper feed roller 1. The paper feed roller 1 and the separation roller 2 are rotationally driven in the direction of arrow A by a paper feed motor (not shown), and the transport rollers 8a and 8b are driven by a transport motor (not shown), and the document 14 is a nip position N between the separation roller 2 and the retard roller 3. It is sent to. The retard roller 3 includes a torque limiter (not shown), and the load of the torque limiter serves as a separation force for the document 14, and only one document on the side in contact with the separation roller 2 is separated from the bundle of documents 14 and conveyed. It is sent to the nip position P between the roller 8a and the pressing roller 9a. When the document is nipped at the nip position P between the conveyance roller 8a and the pressing roller 9a, the paper feed motor stops, the document is sent to the reading units 10a and 10b by the conveyance roller 8a, and the image information on the document surface is read. The paper is discharged from the discharge port 16 by the transport rollers 8b and 9b. When the paper feed motor is driven again, the second and subsequent originals are sent to the reading unit, and thereafter, the same operation is repeated to sequentially read all the originals set on the upper original hopper 6.

  Next, a paper feeding operation when a document is set on the front document hopper 7 of the apparatus main body will be described in detail with reference to FIGS.

  When a document is fed from the front document hopper 7, the document 15 is fed from a sheet feed port 18 shown in FIGS. First, when the slide switch 50a of the document guide switching device 50 in FIG. 4A is moved in the direction of arrow Z and the document guide 5 is switched in the direction of arrow E shown in FIG. A conveying path up to 2 is formed. In conjunction with this, when the document insertion detection sensor 12 (shown in FIG. 1) detects the document insertion on the front document hopper 7, the sheet feeding motor is controlled to start. That is, when the document 15 is inserted from the sheet feed port 18 and the document insertion detection sensor 12 detects this, the sheet feed roller 1 and the separation roller 2 are driven to rotate in the direction of arrow A by the sheet feed motor. On the other hand, since the retard roller 3 is elastically pressed by the separation roller 2 with a predetermined pressure, it is rotationally driven in the direction of arrow A by mutual friction. Further, the paper feed driven roller 4 is also urged to the retard roller 3 by the spring 4a provided on the support shaft 22 (shown in FIG. 4A), so that the document 15 is fed out by the paper feed driven roller 4 and the retard roller. 3 and the paper feed driven roller 4 are inserted to the nip position Q, the document 15 is nipped at the nip position Q and pulled into the apparatus. Here, since the document guide 5 is switched in the direction of arrow E in FIG. 2B as described above, a predetermined interval is generated on the circumference of the retard roller 3, and the nip between the separation roller 2 and the retard roller 3. A document conveyance path is formed so as to guide to position N. Then, the document 15 inserted from the sheet feeding port 18 is sent to the nip position N between the separation roller 2 and the retard roller 3, and passes through this to the nip position P between the conveying roller 8a and the pressing roller 9a in FIG. It is. Thereafter, the document 15 is read and discharged from the discharge port 16 in the same manner as when fed from the upper document hopper 6. Further, when a plurality of documents are inserted from the sheet feeding port 18, the separation effect at the nip position N between the separation roller 2 and the retard roller 3 acts, so that only one sheet on the upper surface is separated to the reading unit. It is sent. At this time, the retard roller 3 stops rotating in order to prevent the second and subsequent originals from entering, so the second and subsequent originals are stopped at the nip position N between the separation roller 2 and the retard roller 3. When the first document is transported to the transport roller 8a, the paper feed motor is stopped, and the same operation as when the original is fed from the upper document hopper 6 is repeated to insert the first document from the paper feed port 18. The entire document 15 can be read.

  The document guide switching device 50 described above may constitute a control system so that when a document is inserted into the upper document hopper 6 or the front document hopper 7, the conveyance path is automatically switched.

A paper feeding device and an image reading device according to the present invention are provided with a paper feeding roller that feeds paper, a lower side of the paper feeding roller, and downstream of the paper feeding direction, and rotates in the paper feeding direction. In a sheet feeding device having a driven separation roller and a retard roller that is pressed against and urged by the separation roller and is rotatable at a predetermined torque or more, the shaft is rotatably supported and is urged by a predetermined pressure on the retard roller. ADF having a configuration in which a document path is arranged in the height direction, and a paper feed port or a paper feed guide path for inserting paper is provided at a nip position between the paper feed driven roller and the retard roller. When scanning several pages with a scanner, it is possible to easily insert and read a document from another direction without setting it in the document hopper above the device. When set, even if the original paper is buckled and its original weight buckles and thin paper thickness originals that cannot be stably fed and separated, so-called weak paper can be supplied, stable paper feeding can be performed, paper can be fed out, It is useful as a paper feeding device and an image reading device that feeds and reads a document.

1 is a configuration diagram illustrating an image reading apparatus including a paper feeding device according to an embodiment of the present invention. 1A is an enlarged explanatory diagram showing a paper feeding method of a paper feeding device provided in the image reading device of FIG. 1, and FIG. 1B is an enlarged explanatory diagram showing another paper feeding method of the paper feeding device provided in the image reading device of FIG. 2A is a perspective view showing a document guide and a document guide switching device included in the sheet feeding device of FIG. 2A, and FIG. 3B is an enlarged cross-sectional view of the document guide switching device of FIG. 2A is a perspective view showing a document guide and a document guide switching device included in the sheet feeding device of FIG. 2B, and FIG. 4B is an enlarged cross-sectional view of the document guide switching device of FIG. General structure of an image reading apparatus having a conventional document conveying mechanism

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feed roller 2 Separation roller 3 Retard roller 4 Feed driven roller 4a Spring 5 Document guide 6 Upper document hopper 7 Front document hopper 8a Transport roller 8b Transport roller 9a Press roller 9b Press roller 10a Image sensor (surface reading)
10b Image sensor (back side reading)
11a Platen roller (surface reading)
11b Platen roller (back side reading)
12 Document Insertion Detection Sensor 13 Document Presser 14 Document (Upper Document Hopper)
15 Document (forward document hopper)
16 Discharge port 17 Paper feed port (upper hopper)
18 Paper feed slot (front hopper)
19 Spindle (retard roller holding plate)
21 Spindle (retard roller)
22 Support shaft (feed driven roller)
23 Image reading device 50 Document guide switching device 50a Slide switch 50b Lock leaf spring 50c Cam 50e Slide switch side recess 50f Cam side recess (when feeding forward)
50g Recessed cam side (Upper paper feeding)
N Nip position (nip position between feed roller and retard roller)
P Nip position between transport roller and pressure roller Q Nip position between retard roller and paper feed driven roller

Claims (6)

A paper feed roller for feeding paper, a separation roller provided below the paper feed roller and downstream of the paper feed direction, and driven to rotate in the paper feed direction; In a paper feeding device having a retard roller that is biased and is rotatable at a predetermined torque or more, a paper feed driven roller that is rotatably supported and biased to the retard roller with a predetermined pressure, and the paper feed A sheet feeding device having a sheet feeding port or a sheet feeding guide path into which a sheet is inserted at a nip position between a driven roller and a retard roller. The paper feed driven roller is disposed such that the nip position between the paper feed driven roller and the retard roller is on the upstream side in the rotation direction of the retard roller from the nip position between the separation roller and the retard roller. The paper feeding device according to claim 1. Provided on the outer periphery of the retard roller for guiding the sheet from the nip position between the sheet feed driven roller and the retard roller to the nip position between the separation roller and the retard roller, in the vicinity of the sheet feed driven roller. A guide member that can rotate around a shaft, and when the sheet enters from a nip position between the paper feed driven roller and the retard roller, the guide member and the circumference of the retard roller A conveying space having a predetermined width is formed between the two, and when the sheet enters from the direction of the sheet feeding roller, the leading end of the guide member moves to the axis side of the retard roller. Item 2. The sheet feeding device according to Item 1. A paper feed roller that feeds the original, a separation roller that is provided below the paper feed roller and downstream of the paper feed direction, and is driven to rotate in the paper feed direction. In an image reading apparatus having a retard roller that is biased and is rotatable at a predetermined torque or more, and a reading unit that reads a document provided downstream of the separation roller in the document feeding direction, the support shaft is rotatable. And a sheet feed driven roller that is urged by the retard roller with a predetermined pressure, and a sheet feed port or a sheet feed guide path for inserting a sheet at a nip position between the sheet feed driven roller and the retard roller. An image reading apparatus. The paper feed driven roller is disposed such that the nip position between the paper feed driven roller and the retard roller is on the upstream side in the rotation direction of the retard roller from the nip position between the separation roller and the retard roller. The image reading apparatus according to claim 4, wherein: Provided on the outer periphery of the retard roller for guiding the document from the nip position between the feed driven roller and the retard roller to the nip position between the separation roller and the retard roller, in the vicinity of the feed driven roller. A guide member that can rotate around a shaft, and when the sheet enters from a nip position between the paper feed driven roller and the retard roller, the guide member and the circumference of the retard roller A conveying space having a predetermined width is formed between the two, and when the sheet enters from the direction of the sheet feeding roller, the leading end of the guide member moves to the axis side of the retard roller. Item 5. The image reading apparatus according to Item 4.

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