JP2008252387A - Image reader, and control method and control program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader that conveys a plurality of originals stably and continuously, cleans the contact glass of a read sensor, and can reduce a stripe formed in a read image. <P>SOLUTION: In the image reader that conveys an original for reading by the read sensor 1, there is an elastic member 16 projecting outside on the outer periphery of a platen roller 10 provided at a position opposite to the read sensor 1. By the detection of the front or rear end of the original by an original detection sensor 14 as a reference, the platen roller 10 is rotated by not less than one rotation between the originals to be conveyed, and brings the elastic member 16 into contact with contact glass 20 in the read sensor 1, thus cleaning the surface of the contact glass 20 each time the image is read. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image reading apparatus such as a scanner that reads an image of a document conveyed using a conveyance mechanism such as a roller, a control method for the image reading apparatus, and a control program for the image reading apparatus.

  In this type of conventional image reading apparatus, dust such as paper dust adhering to a document or scraping scraps on the conveyance roller may adhere to the contact glass of the reading sensor.

  If dust is attached to the contact glass during image reading, black or color streaks may occur in the read image, which degrades the image quality. Therefore, when such a streak occurs in the image, the user cleans the contact glass of the reading sensor arranged in the image reading apparatus.

  As a technique for reducing such a burden on the user, a platen roller is rotatably provided so as to face the reading sensor, and an elastic member extending in the main scanning direction of the reading sensor is protruded on the outer periphery of the platen roller, thereby the platen roller. There is one that cleans the surface of the contact glass when the elastic member contacts the contact glass surface of the reading sensor during rotation (Patent Document 1).

The elastic member is configured to be deformed to the same surface as the outer peripheral surface of the platen roller when the protruding portion from the outer periphery of the platen roller is in contact with the contact glass of the reading sensor, and does not hinder the rotation of the platen roller. In addition, the contact glass can be reliably cleaned.
Japanese Patent No. 3645737

  However, in Patent Document 1, since the elastic member protruding from the outer periphery of the platen roller extends in the longitudinal direction of the reading sensor, which is the main scanning direction of image reading, the platen roller continues to rotate during document conveyance. The leading edge of the document may be caught on the elastic member.

  In addition, since the elastic member appears in the read image, and a part of the original is pressed against the contact glass of the reading sensor by the elastic member and undulates, the density unevenness and the out-of-focus may occur in the read image.

  For these reasons, conventionally, for example, when the power is turned on, only once before starting image reading of a plurality of documents, or once after completion of image reading of a plurality of documents, the platen roller is moved only once. The contact glass surface of the reading sensor is cleaned by rotating it.

  However, if dust such as paper dust adheres to the contact glass while a plurality of documents are continuously fed and conveyed, streaks occur in the image read by the reading sensor. If dust remains attached, streaks continue to occur in images read after the original.

  Therefore, the present invention provides an image reading apparatus and an image reading apparatus capable of reducing streaks generated in a read image by cleaning a contact glass of a reading sensor while stably conveying a plurality of documents. It is an object to provide a control method and a control program for an image reading apparatus.

  In order to achieve the above object, an image reading apparatus according to the present invention includes an image reading unit that reads an image formed on a document via a contact member that contacts a document conveyed on a conveyance path, and the image reading unit sandwiching the conveyance path. A rotating member disposed so as to face the image reading means, and an elastic member that protrudes from the outer peripheral portion of the rotating member and contacts the contact member when the rotating member rotates to clean the surface of the contact member An image reading device comprising: a document detection unit that detects at least one of a leading edge and a trailing edge of the document conveyed on the conveyance path; a driving unit that rotates the rotating member; and a control unit that controls the driving unit. In the apparatus, when the document detection unit detects the leading edge or the trailing edge of the document, the control unit is configured such that the leading edge of the document reaches the image reading unit or the trailing edge of the document is the image. After passing through the reading means, rotating the rotating member for controlling the drive means so as to clean the surface of the contact member with the elastic member, and wherein the.

  An image reading apparatus according to the present invention is configured so that an image reading unit that reads an image formed on a document via a contact member that contacts a document conveyed on a conveyance path, and the image reading unit across the conveyance path. A rotating member that is disposed, an elastic member that protrudes from an outer peripheral portion of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member; Document detecting means for detecting a document to be detected, driving means for rotating the rotating member, and control means for controlling the driving means to rotate the rotating member when the document detecting means detects the document. The rotational speed of the rotating member is equal to or higher than the document conveying speed as the first rotating speed, and the rotating speed of the rotating member is lower than the document conveying speed as the second rotating speed. When the rotation speed is set to be the third rotation speed, the rotation member is rotated at the third rotation speed before the document enters between the rotation member and the contact member. When the surface of the contact member is cleaned with the elastic member and the document enters between the rotating member and the contact member, the rotating member is rotated at the first rotational speed, and the leading end of the document is rotated. The control means controls the driving means so as to rotate the rotating member at a second rotational speed after a predetermined time has passed after passing between the member and the contact member.

  An image reading apparatus control method according to the present invention includes an image reading unit that reads an image formed on a document via a contact member that contacts a document conveyed on a conveyance path, and is opposed to the image reading unit across the conveyance path. A rotating member arranged so as to project, an elastic member that protrudes from an outer periphery of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member; and the rotating member In the control method of the image reading apparatus, the document detection step for detecting at least one of the leading edge and the trailing edge of the document conveyed on the conveyance path, and the leading edge of the document in the document detection step When the trailing edge is detected, the rotating member is rotated before the leading edge of the document reaches the image reading means or after the trailing edge of the document passes the image reading means. Characterized in that it comprises a control step of controlling the drive means so as to clean the surface of the contact member with the elastic member.

  An image reading apparatus control method according to the present invention includes an image reading unit that reads an image formed on a document via a contact member that contacts a document conveyed on a conveyance path, and is opposed to the image reading unit across the conveyance path. A rotating member arranged so as to project, an elastic member that protrudes from an outer periphery of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member; and the rotating member And a driving means for rotating the image reading apparatus, the original detecting step for detecting the original conveyed on the conveying path, and the driving means when the original is detected in the original detecting step. And a control step of rotating the rotary member, wherein the control step sets a rotational speed at which the peripheral speed of the rotary member is equal to or higher than the document transport speed as the first rotational speed. When the rotation speed of the rotating member is lower than the document conveying speed is the second rotation speed and the arbitrary rotation speed is the third rotation speed, the document is placed between the rotation member and the contact member. Before rushing, the rotating member is rotated at the third rotational speed to clean the surface of the contact member with the elastic member, and when the document rushes between the rotating member and the contact member, The rotating member is rotated at the first rotating speed, and the rotating member is rotated at the second rotating speed after a predetermined time after the leading edge of the document passes between the rotating member and the contact member. The drive means is controlled.

  The control program of the image reading apparatus of the present invention opposes the image reading unit that reads an image formed on a document via a contact member that contacts the document conveyed on the conveyance path, and the image reading unit across the conveyance path. A rotating member arranged so as to project, an elastic member that protrudes from an outer periphery of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member; and the rotating member In the control program of the image reading apparatus, the document detection step for detecting at least one of the leading edge and the trailing edge of the document conveyed on the conveyance path, and the leading edge of the document in the document detection step When the trailing edge is detected, before the leading edge of the document reaches the image reading means or after the trailing edge of the document passes the image reading means, the rotating unit The executing a control step for controlling the drive means so as to clean the surface of the contact member in the elastic member is rotated, to a computer, characterized in that.

  The control program of the image reading apparatus of the present invention opposes the image reading unit that reads an image formed on a document via a contact member that contacts the document conveyed on the conveyance path, and the image reading unit across the conveyance path. A rotating member arranged so as to project, an elastic member that protrudes from an outer periphery of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member; and the rotating member And a driving means for rotating the image reading apparatus, the document detecting step for detecting the document conveyed on the conveyance path, and the driving means when the document is detected in the document detecting step. And causing the computer to execute a control step of rotating the rotary member, wherein the control step is such that the peripheral speed of the rotary member is equal to or higher than the document transport speed. Is the first rotation speed, the rotation speed of the rotating member is lower than the document conveyance speed, the second rotation speed, and the arbitrary rotation speed is the third rotation speed. Before entering between the rotating member and the contact member, the rotating member is rotated at the third rotational speed to clean the surface of the contact member with the elastic member, and the document is the rotating member and the contact member. The rotary member is rotated at the first rotational speed, and the rotary member is moved after a predetermined time after the leading edge of the document passes between the rotary member and the contact member. The drive means is controlled to rotate at a second rotation speed.

  According to the present invention, it is possible to clean the contact glass of the reading sensor with the cleaning member attached to the rotating member while stably conveying a plurality of documents, thereby reducing streaks generated in the read image. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic sectional view for explaining an image reading apparatus according to a first embodiment of the present invention, and FIG. 2 is a perspective view for explaining a platen roller.

  As shown in FIG. 1, the image reading apparatus moves up until the document table 7 on which the document 8 is loaded comes into contact with the pickup roller 6, and the document 8 picked up by the pickup roller 6 is fed by the feeding roller 4. Is done.

  When two or more originals 8 are picked up simultaneously by the pickup roller 6, the originals 8 are separated one by one by the separation roller 11 and fed. Then, the fed image of the document 8 is read by the reading sensor 1, and the image data is transferred to an image processing unit (not shown). The leading edge and trailing edge of the document 8 to be fed are detected by the registration sensor 14, and the rotation and stop of the registration roller 3 a are controlled using the signal of the registration sensor 14 to control the conveyance timing and the like.

  A platen roller (rotating member) 10 is provided at a position facing the reading sensor 1 via a certain gap.

  As shown in FIG. 2, the platen roller 10 is formed in a cylindrical shape by joining a semi-cylindrical black member 17 and a semi-cylindrical white member 18 to each other by concavo-convex fitting or the like in the radial direction. The rotational position of the platen roller 10 is detected by the position sensor 21.

  Normally, the platen roller 10 is stopped, and when the background color of the document 8 is switched, the platen roller 10 is driven to rotate by a driving motor 15 such as a stepping motor controlled by the control unit 31 (see FIG. 4).

  For example, in the case of a paper document with low density of printing or printing and easy to see through, the platen roller 10 is rotated so that the white member 18 of the platen roller 10 faces the reading sensor 1 to change the background color of the document. Switch to white to emphasize printing and printing characters.

  Further, in the case of a paper document that is easily printed on both sides, the platen roller 10 is rotated so that the black member 17 of the platen roller 10 faces the reading sensor 1, and the background color of the document is switched to black. Eliminate show-through.

  Further, when performing OCR processing for recognizing a character image of a read original, the image data must be filed by aligning the read data based on the outline of the original, the edge of the original, or the reference hole. It needs to be clear.

  Since a normal document is white, if the platen roller 10 disposed opposite to the reading sensor 1 that reads an image is black, the outline, edge, hole, and the like of the read document are emphasized, and the reference when performing OCR processing can do.

  Thus, by rotating the platen roller 10, the background color of the document can be switched and selected.

  Further, an elastic member 16 extending along the axial direction of the platen roller 10 is interposed at a joint portion along the axial direction of the black member 17 and the white member 18 of the platen roller 10 so as to protrude from the outer peripheral surface of the platen roller 10. It is disguised. As the elastic member 16, a rubber material, a material coated with a rubber material, a brush, a cloth, or the like can be used.

  The contact glass 20 is cleaned by the elastic member 16 coming into contact with the contact glass 20 (see FIG. 3) of the reading sensor 1 by the rotation of the platen roller 10.

  Specifically, after the registration sensor 14 detects the leading edge of the document, driving of the platen roller 10 is started. If the platen roller 10 is at the stop position in FIG. 1 before the leading edge of the conveyed document reaches the gap between the platen roller 10 and the reading sensor 1, the platen roller 10 is rotated about 3/4 or more times. The controller 31 controls the drive motor 15 so that the cleaning of the contact glass 20 of the reading sensor 1 by the cleaning member 16 is completed once.

  After the cleaning of the contact glass 20 by the cleaning member 16 is completed once, the control unit 31 moves the platen roller 10 to a position where the selected background color member (the black member 17 or the white member 18) faces the reading sensor 1. And the drive motor 15 is controlled so as to hold the platen roller 10 at a fixed holding torque at the opposite position. While the platen roller 10 is rotating, the leading edge of the document 8 passes through the gap between the platen roller 10 and the reading sensor 1.

  As described above, when the leading edge of the document 8 passes through the gap between the platen roller 10 and the reading sensor 1, the platen roller 10 completes cleaning of the contact glass 20 by the cleaning member 16 and continues to rotate. Therefore, the control unit 31 performs control such as ensuring a waiting time from the time when the registration sensor 14 detects the leading edge of the document 8 to the time when the rotation of the platen roller 10 is started, and adjusting the rotation speed of the platen roller 10. Is done appropriately.

  In this case, the rotation direction of the platen roller 10 is preferably a direction for guiding the leading edge of the document 8 being conveyed.

  As described above, the rotation control of the platen roller 10 is performed for each conveyed document, prevents dust from adhering to the contact glass 20 that is the reading surface of the reading sensor 1, and realizes high-quality image reading. .

  The document 8 that has passed through the reading sensor 1 is transported to the transport roller 3 and discharged onto the discharge tray 9 by the discharge roller 5.

  Further, in these series of document conveying operations, in order to maintain an appropriate distance between the document 8 and the succeeding document, the paper feed of the pickup roller 6 is performed based on the detection timing at which the registration sensor 14 detects the trailing edge of the document 8 and the like. The timing is controlled by the control unit 31 and is continued until all the documents 8 stacked on the document table 7 are fed.

  After all the documents 8 loaded on the document table 7 are transported, the document table 7 descends and returns to the home position.

  The upper unit 2 having the registration roller 3a, the conveyance roller 3, the feeding roller 4, the reading sensor 1, and the platen roller 10 can be rotated with respect to the lower unit 12 via a hinge 13 to open and close the conveyance path. can do.

  By rotating the upper unit 2 with respect to the lower unit 12 to open the conveyance path, the registration roller 3a, the conveyance roller 3, the platen roller 10, the reading sensor 1, the cleaning of the conveyance path, and the document jammed in the conveyance path. Can be taken out.

  The rotation operation of the upper unit 2 can be detected using an open / close detection sensor (not shown), and the control unit 31 confirms that the upper unit 2 has been returned to its original position and the conveyance path has been closed. Then, control is performed to enter the feeding standby mode.

  As described above, the background color can be switched by the rotation of the platen roller 10 and the surface of the contact glass of the reading sensor 1 can be accurately cleaned without causing the document 8 to be damaged or soiled.

  FIG. 3A is a diagram illustrating a state in which the platen roller 10 is stopped before the reading process of the image of the document 8 by the reading sensor 1 is started.

  Based on the detection of the position sensor 21, the platen roller 10 stands by at a predetermined position shown in the figure.

  When the document 8 is conveyed and the leading edge of the document 8 is detected by the registration sensor 14, the control unit 31 controls the drive motor 15 so that the cleaning of the contact glass 20 of the reading sensor 1 by the cleaning member 16 is completed once. Then, the platen roller 10 is rotated.

  FIG. 3B is a diagram illustrating a state in which the platen roller 10 is rotating.

  The platen roller 10 rotates in the direction of the arrow in the figure, and the elastic member 16 comes into contact with the contact glass 20 and is elastically deformed and falls down in the center direction of the platen roller 10. A part of the groove enters an axial groove 19 formed at the mounting position.

  The platen roller 10 continues to rotate even after the cleaning of the contact glass 20 by the cleaning member 16 is completed once. When the white color is selected as the background color, the platen roller 10 is again at the position shown in FIG. When to stop.

  As described above, before the leading edge of the document 8 enters the gap between the platen roller 10 and the reading sensor 1, the control unit 31 has completed the cleaning of the contact glass 20 by the cleaning member 16 once by the platen roller 10. Thus, the drive motor 15 is controlled. Therefore, even if the platen roller 10 continues to rotate to a predetermined position, the leading end of the document 8 that has entered the gap between the platen roller 10 and the reading sensor 1 is not caught by the elastic member 16.

  In this embodiment, the platen roller 10 is rotated and the contact glass 20 is cleaned by the cleaning member 16 every time the document is read based on the detection of the leading edge of the document. However, the detection of the trailing edge of the document is used as a reference. In addition, after reading the document, the contact glass 20 may be cleaned by the cleaning member 16 by rotating the platen roller 10 at a timing when the elastic member 16 does not contact the trailing edge of the document.

  In this case, the platen roller 10 may be rotated after waiting for the time required for the trailing edge of the document 8 to pass the reading sensor 1 after the registration sensor 14 detects the trailing edge of the document 8.

  In addition, when the leading edge of the subsequent document 8 enters the gap between the platen roller 10 and the reading sensor 1, the platen roller 10 completes cleaning of the contact glass 20 by the cleaning member 16 and continues to rotate. Then, on the basis of detection of the trailing edge of the document 8, the pickup, feeding or conveyance of the subsequent document 8 by the registration roller 3a is controlled.

  The waiting time from when the registration sensor 14 detects the trailing edge of the document 8 until the rotation of the platen roller 10 starts, and the rotation of the platen roller 10 from the time when the registration sensor 14 detects the leading edge of the document 8. The waiting time until the start is calculated by the control unit 31. These waiting times may be selected from a table in which the control unit 31 stores a predetermined set time.

  In the present embodiment, the case where the white member 18 stops the platen roller 10 at a position facing the reading sensor 1 has been described, but the case where the black member 17 stops the platen roller 10 at a position facing the reading sensor 1. First, from the state of FIG. 1, the position where the platen roller 10 is rotated halfway is set as the stop position.

  Then, before the document 8 is conveyed, the contact glass 20 is cleaned by the cleaning member 15 by rotating the platen roller 10 about ¼ rotation or more. Thereafter, the rotation of the platen roller 10 is continued, and is stopped when the platen roller 10 is rotated once.

  Furthermore, in the present embodiment, the case where the platen roller 10 is rotated for each conveyed document and the contact glass 20 is cleaned by the cleaning member 16 has been described. However, for example, every two documents to be conveyed or 3 The contact glass 20 may be cleaned by the cleaning member 16 by rotating the platen roller 10 for every sheet or more.

  Further, the platen roller 10 may be rotated at a high speed, and the cleaning member 16 may be brought into contact with the contact glass 20 at least twice for cleaning.

  FIG. 4 shows an example of a control system for realizing the rotation operation and the stop operation of the platen roller 10.

  The document detection unit 32 detects the leading edge or the trailing edge of the conveyed document 8 based on a signal from the registration sensor 14. The image reading unit 33 causes the reading sensor 1 to read an image of the document conveyed in accordance with an instruction from the control unit 31. The drive unit 34 drives the drive motor 15 according to an instruction from the control unit 31 to rotate the platen roller 10.

  When the document detection means 32 detects the leading edge of the conveyed document 8 or the trailing edge of the preceding document, the controller 31 cleans the document 8 before the leading edge of the document 8 enters the gap between the platen roller 10 and the reading sensor 1. The driving means 34 is controlled to rotate the platen roller 10 so that the cleaning by the member 16 is completed.

  At this time, the control unit 31 instructs the image reading unit 33 when to read the image of the document 8 by the reading sensor 1. Further, based on the detection of the leading edge of the document 8, the control unit 31 rotates the platen roller 10 when the leading edge of the document 8 passes the reading sensor 1 and then stops the driving unit 34 at a predetermined position. To control.

  As described above, in this embodiment, the control unit 31 controls the reading of the image of the document 8 and the rotation timing of the platen roller 10 based on the detection timing of the document detection unit 32. The platen roller 10 is rotated when the leading edge of the document 8 passes through the gap between the platen roller 10 and the reading sensor 1 by the control synchronized with the passage of the leading edge of the document 8 or the trailing edge of the preceding document. Further, the platen roller 10 may be rotated until the document is sandwiched between the downstream conveying roller pair 3. In this way, paper jams of the document 8 can be prevented, and the document 8 can be conveyed stably.

  Further, in the present embodiment, the case where the elastic member 16 is extended in the axial direction of the platen roller 10 is illustrated, but for example, as shown in FIG. The elastic member 16 may be arranged in a V shape as shown in FIG. 5B.

  In this way, by inclining the elastic member 16 with respect to the axis of the platen roller 10, the contact impact generated when the elastic member 16 contacts and cleans the contact glass 20 by the rotation of the platen roller 10 is dispersed. It is possible to prevent the load torque of the platen roller 10 from being excessively high during cleaning by the cleaning member 16.

  Further, in order to disperse such contact impact, as shown in FIG. 6A, the elastic member 16 is divided into a plurality of parts in the axial direction of the platen roller 10, and the plurality of divided parts are shifted in the circumferential direction. In addition, as shown in FIG. 6B, in order to more reliably clean the contact glass 20 and to disperse the contact impact, the elastic members 16 are arranged in two or more rows. Also good.

  As described above, in the present embodiment, the document 8 to be conveyed is read one by one, before image reading, or after image reading, with the leading edge or the trailing edge of the document 8 detected by the registration sensor 14 as a reference. The platen roller 10 rotates.

  Thereby, dust adhered to the contact glass 20 of the reading sensor 1 during conveyance of the document 8 can be accurately cleaned by the elastic member 16, and a high-quality image can be read.

  Further, even if dust adheres to the contact glass 20 during image reading, the platen roller 10 is rotated until the next conveyed document 8 reaches the platen roller 10, and contact is made by the elastic member 16. Since the glass 20 is cleaned, it is possible to prevent streaks from occurring in the read image of the original 8 conveyed next.

  Next, an image reading apparatus according to the second embodiment of the present invention will be described with reference to FIGS. Note that portions that overlap or correspond to those in the first embodiment will be described using the reference numerals.

  In the first embodiment, the platen roller 10 rotates before the front end of the document 8 passes through the gap between the platen roller 10 and the reading sensor 1, and the contact glass 20 is cleaned by the cleaning member 16. When the tip of the sheet passes through the gap between the platen roller 10 and the reading sensor 1, the rotation continues to a predetermined position.

  However, since the conveyance speed of the document 8 and the peripheral speed of the platen roller 10 are irrelevant, a document or the like whose tip is bent is clogged in the gap between the platen roller 10 and the reading sensor 1. There is also. In the case of a flexible and thin document, the leading edge of the document may collide with the platen roller 10 and be jammed.

  Therefore, in this embodiment, an example will be described in which the rotation timing and rotation speed of the platen roller 10 are controlled so that the leading edge of the document 8 is not clogged with the gap between the platen roller 10 and the reading sensor 1.

  FIG. 7 shows a state in which the control unit 31 controls the driving unit 34 based on the detection of the leading edge of the document 8 by the registration sensor 14, and the platen roller 10 in a standby state starts to rotate in the direction of the arrow in the figure. FIG.

  The platen roller 10 rotates while being accelerated / decelerated until the peripheral speed is substantially equal to the conveying speed of the document 8, and the cleaning of the contact glass 20 by the cleaning member 16 is performed. A change in the rotation speed (third rotation speed) of the platen roller 10 until the peripheral speed substantially equal to the conveyance speed of the document 8 is arbitrary. That is, it may be decelerated after the peripheral speed is sufficiently higher than the transport speed.

  FIG. 8 is a diagram illustrating a state in which the leading edge of the document 8 enters the gap between the platen roller 10 and the reading sensor 1.

  At this time, the control unit 31 controls the driving unit 34 so that the platen roller 10 has a rotational speed (first rotational speed) substantially equal to or higher than the conveyance speed of the document 8.

  FIG. 9 shows a state in which the leading end of the document 8 is nipped and conveyed by the conveyance roller pair 3 on the downstream side substantially simultaneously with or before and after the rotation of the platen roller 10 in the rotation stopped state (second rotation speed). FIG.

  While the reading sensor 1 reads the image of the document 8, the white member 18 of the platen roller 10 always faces the reading sensor 1, and the background color included in the read image is not switched. The rotation operation and the stop operation of the platen roller 10 are repeated for each original document conveyed.

  The second rotation speed is not a stop of the rotation of the platen roller 10 but a sufficiently low rotation speed so that the background color of the document 8 is not switched from the white member 18 to the black member 17 during reading of one image. The rotation speed may be set to a proper value.

  When the background color of the document 8 is black, the half-rotated state from the state of FIG. 7 is used as the standby position of the platen roller 10 and the same rotation operation as described above is performed, and the document 8 is transported before or ahead. The controller 31 cleans the contact glass 20 with the cleaning member 16 after transporting the document, and rotates the platen roller 10 so that the front end of the document 8 easily passes through the gap between the platen roller 10 and the reading sensor 1. The drive means 34 is controlled.

  As described above, in the present embodiment, the platen roller 10 is rotated by a predetermined amount at a rotational speed almost equal to or higher than the conveyance speed of the document 8 immediately before the leading edge of the document 8 passes the reading sensor 1.

  As a result, the leading edge of the document 8 easily passes through the gap between the platen roller 10 and the reading sensor 1, and the leading edge of the document 8 is clogged by the gap even in the case of a document with a folded tip or a flexible and thin document. The document 8 can be stably conveyed without any problems.

  Since the platen roller 10 necessary for image reading is stopped after a predetermined time, the platen roller 10 continues to rotate until the leading edge of the document 8 is held between the downstream conveying roller pair 3 and the conveyance of the document 8 is stabilized. As a result, the document 8 can be conveyed more reliably. Other configurations and operational effects are the same as those in the first embodiment.

  In addition, this invention is not limited to what was illustrated by said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, in each of the above embodiments, the platen roller has two colors. However, the present invention is not limited to this, and the present invention can be applied to a platen roller of one color or a platen roller of three colors or more. is there.

  The object of the present invention is achieved by executing the following processing. That is, a storage medium that records a program code of software that realizes the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus is stored in the storage medium. This is the process of reading the code.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Moreover, the following can be used as a storage medium for supplying the program code. For example, floppy (registered trademark) disk, hard disk, magneto-optical disk, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM or the like. Alternatively, the program code may be downloaded via a network.

  Further, the present invention includes a case where the function of the above-described embodiment is realized by executing the program code read by the computer. In addition, an OS (operating system) running on the computer performs part or all of the actual processing based on an instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Is also included.

  Furthermore, a case where the functions of the above-described embodiment are realized by the following processing is also included in the present invention. That is, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

1 is a schematic sectional view for explaining an image reading apparatus according to a first embodiment of the present invention. It is a perspective view for demonstrating a platen roller. (A) is a figure which shows the state which the platen roller has stopped before starting the reading process of the image of a document by a reading sensor, (b) is a figure which shows the state in which the platen roller is rotating. It is a block diagram for demonstrating an example of the control system for implement | achieving the rotation operation | movement and stop operation | movement of a platen roller. It is a perspective view for demonstrating the modification of the cleaning member attached to a platen roller. It is a perspective view for demonstrating the modification of the cleaning member attached to a platen roller. FIG. 6 is a diagram illustrating a state in which a platen roller that is in a standby state starts to rotate based on the detection of the leading edge of a document by a registration sensor. FIG. 6 is a diagram illustrating a state in which a leading end of a document has entered a gap between a platen roller and a reading sensor. FIG. 5 is a diagram illustrating a state where the leading edge of a document is nipped and conveyed by a pair of conveyance rollers on the downstream side at the same time or before and after the rotation of a rotating platen roller (second rotation speed).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reading sensor 2 Upper unit 3 Conveyance roller 3a Registration roller 4 Paper feed roller 5 Paper discharge roller 6 Pickup roller 7 Document base 8 Document 9 Paper discharge tray 10 Platen roller 11 Separation roller 12 Lower unit 13 Hinge 14 Registration sensor 15 Drive motor 16 Elastic member 17 Black member 18 White member 19 Axial groove 20 Contact glass 21 Position sensor 31 Control unit 32 Document detection means 33 Image reading means 34 Driving means

Claims (11)

An image reading means for reading an image formed on the document through a contact member that contacts the document conveyed on the conveyance path;
A rotating member arranged to face the image reading means across the conveyance path;
An elastic member that protrudes from the outer peripheral portion of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member;
Document detection means for detecting at least one of a leading edge and a trailing edge of the document conveyed on the conveyance path;
Driving means for rotating the rotating member;
An image reading apparatus comprising: control means for controlling the driving means;
When the document detection unit detects the leading edge or the trailing edge of the document, the control unit is configured so that the leading edge of the document reaches the image reading unit or after the trailing edge of the document passes the image reading unit. An image reading apparatus, wherein the driving unit is controlled to rotate a rotating member and clean the surface of the contact member with the elastic member.   The image reading apparatus according to claim 1, wherein the control unit controls the driving unit to rotate the rotating member every time a predetermined number of documents are conveyed. An image reading means for reading an image formed on the document through a contact member that contacts the document conveyed on the conveyance path;
A rotating member arranged to face the image reading means across the conveyance path;
An elastic member that protrudes from the outer peripheral portion of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member;
Document detection means for detecting a document transported along the transport path;
Driving means for rotating the rotating member;
A control means for controlling the driving means to rotate the rotating member when the original detection means detects the original;
A rotation speed at which the peripheral speed of the rotation member is equal to or higher than the document conveyance speed is defined as a first rotation speed,
The rotational speed at which the peripheral speed of the rotating member is slower than the document conveying speed is set as the second rotational speed,
If any rotation speed is the third rotation speed,
Before the document enters between the rotating member and the contact member, the rotating member is rotated at the third rotational speed to clean the surface of the contact member with the elastic member,
When the document enters between the rotating member and the contact member, the rotating member is rotated at the first rotation speed,
The control means controls the driving means so as to rotate the rotating member at a second rotational speed after a predetermined time has passed after the leading edge of the document has passed between the rotating member and the contact member; An image reading apparatus.   The image reading apparatus according to claim 3, wherein the rotation member having the second rotation speed is in a stopped state.   The image reading apparatus according to claim 4, wherein when the rotating member is in the stopped state, the cleaning member is disposed at a position where the cleaning member does not interfere with the conveyed document.   The image reading apparatus according to claim 1, wherein the elastic member is disposed to be inclined with respect to an axis of the rotating member.   6. The elastic member according to claim 1, wherein the elastic member is divided into a plurality of portions in the axial direction of the rotating member, and the plurality of divided portions are arranged so as to be shifted in the circumferential direction of the rotating member. The image reading apparatus according to claim 1. An image reading means for reading an image formed on the document through a contact member that contacts the document conveyed on the conveyance path;
A rotating member arranged to face the image reading means across the conveyance path;
An elastic member that protrudes from the outer peripheral portion of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member;
In a control method of an image reading apparatus comprising: a driving unit that rotates the rotating member;
A document detection step of detecting at least one of a leading edge and a trailing edge of the document conveyed on the conveyance path;
When the leading edge or the trailing edge of the document is detected in the document detection step, the rotating member is rotated before the leading edge of the document reaches the image reading means or after the trailing edge of the document passes the image reading means. And a control step of controlling the driving means so as to clean the surface of the contact member with the elastic member. An image reading means for reading an image formed on the document through a contact member that contacts the document conveyed on the conveyance path;
A rotating member arranged to face the image reading means across the conveyance path;
An elastic member that protrudes from the outer peripheral portion of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member;
In a control method of an image reading apparatus comprising: a driving unit that rotates the rotating member;
A document detection step for detecting a document transported on the transport path;
A control step of controlling the driving means to rotate the rotating member when a document is detected in the document detection step,
In this control step, a rotational speed at which the peripheral speed of the rotating member is equal to or higher than the document conveying speed is set as a first rotating speed, and a rotating speed at which the peripheral speed of the rotating member is slower than the document conveying speed is set as a second rotating speed, If any rotation speed is the third rotation speed,
Before the document enters between the rotating member and the contact member, the rotating member is rotated at the third rotational speed to clean the surface of the contact member with the elastic member,
When the document enters between the rotating member and the contact member, the rotating member is rotated at the first rotation speed,
The driving means is controlled to rotate the rotating member at a second rotational speed after a predetermined time has passed after the leading edge of the document has passed between the rotating member and the contact member. A method for controlling an image reading apparatus. An image reading means for reading an image formed on the document through a contact member that contacts the document conveyed on the conveyance path;
A rotating member arranged to face the image reading unit across the conveyance path;
An elastic member that protrudes from the outer peripheral portion of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member;
In a control program for an image reading apparatus comprising: a driving unit that rotates the rotating member;
A document detection step of detecting at least one of a leading edge and a trailing edge of the document conveyed on the conveyance path;
When the leading edge or the trailing edge of the document is detected in the document detection step, the rotating member is rotated before the leading edge of the document reaches the image reading means or after the trailing edge of the document passes the image reading means. And a control step of controlling the driving means so as to clean the surface of the contact member with the elastic member. An image reading means for reading an image formed on the document through a contact member that contacts the document conveyed on the conveyance path;
A rotating member arranged to face the image reading means across the conveyance path;
An elastic member that protrudes from the outer peripheral portion of the rotating member, contacts the contact member when the rotating member rotates, and cleans the surface of the contact member;
In a control program for an image reading apparatus comprising: a driving unit that rotates the rotating member;
A document detection step for detecting a document transported on the transport path;
A control step of controlling the driving means to rotate the rotating member when a document is detected in the document detection step;
In this control step, a rotational speed at which the peripheral speed of the rotating member is equal to or higher than the document conveying speed is set as a first rotating speed, and a rotating speed at which the peripheral speed of the rotating member is slower than the document conveying speed is set as a second rotating speed, If any rotation speed is the third rotation speed,
Before the document enters between the rotating member and the contact member, the rotating member is rotated at the third rotational speed to clean the surface of the contact member with the elastic member,
When the document enters between the rotating member and the contact member, the rotating member is rotated at the first rotation speed,
The driving means is controlled to rotate the rotating member at a second rotational speed after a predetermined time has passed after the leading edge of the document has passed between the rotating member and the contact member. A control program for an image reading apparatus.

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