JP2014011684A - Image reading apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce time required for switching between fixed and moving reading modes.SOLUTION: An image reading apparatus comprises a jump base 61 which is protruded above a platen glass and vertically movable at a position of a downstream end 17a in a document feeding direction of the platen glass in a state where the platen glass is opened by a document feeder. The jump base 61 locates a document by receiving the document placed on the platen glass with a stopper 61b in a state where it is protruded above the platen glass at a fixed reading mode, and guides the document, which has been fed to the platen glass by the document feeder, into inside of the document feeder with a guide 61c in a state where it is fallen at a moving reading mode. From above structure, a downstream reading head 6 for reading the document can have a moving reading start position as a reference point for a fixed reading start position, thereby, eliminating the necessity of changing the document position when switching between fixed and moving reading modes and the time required for switching between the modes can be reduced.

Description

  The present invention relates to an image reading apparatus that reads a document, and an image forming apparatus that includes the image reading apparatus in an apparatus main body.

  2. Description of the Related Art Conventionally, an image forming apparatus that forms an image on a sheet is provided with an image reading apparatus that reads an original in an apparatus main body of the image forming apparatus, and copies an original on a sheet based on image reading information of the image reading apparatus. There is something that is.

  As an image reading apparatus, there is one described in Patent Document 1. In this conventional image reading apparatus, a document loaded on a stacking tray is fed from an intermediate portion of a platen glass to an end portion by a document transport unit, and an image of the document is read by an image reading unit located under the platen glass. The paper is discharged to a discharge tray located above the stacking tray. The method of reading the original at this time is referred to as “flow-reading”. In this case, the image reading unit is stopped below the end portion of the platen glass (referred to as “flow reading end portion”) in order to read the original fed from the intermediate portion of the platen glass to the end portion.

  Further, the conventional image reading apparatus is configured such that the user can read a document placed on the upper surface of the platen glass that is released by raising the document conveying unit. The method of reading the original at this time is referred to as “fixed reading”. In this case, the document is placed on the platen glass with an end portion (referred to as a “fixed reading end portion”) opposite to the flow reading end portion of the platen glass as a stacking reference position. In this case, the image reading unit stands by below the fixed reading end, and fixedly reads the document while moving toward the flow reading end with the position as a base point.

JP 2007-259129 A

  However, the conventional image reading apparatus has to move the image reading portion between the flow reading end portion and the fixed reading end portion of the platen glass when switching between the flow reading and the fixed reading. . For this reason, in the conventional image reading apparatus, it takes time to switch between flow reading and fixed reading.

  In addition, the image forming apparatus including the image reading apparatus that requires time for switching between flow reading and fixed reading receives image information while the image reading apparatus is switching the reading method. Therefore, the number of sheet images formed per unit time is reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading apparatus that shortens the switching time between flow reading and fixed reading, and an image forming apparatus including the image reading apparatus.

  An image reading apparatus according to the present invention includes a document placement portion having a document placement surface on which a document is placed, and is openable / closable with respect to the document placement surface, and faces the document placement surface in a closed state. When an original is placed on the original placement surface and an original conveyance portion that conveys the original, the original placed on the original placement surface is read while moving, and the original conveyance portion is In the stopped state, the reading unit that reads the document that is transported to the document placement surface by the document transportation unit and the document that is placed on the document placement surface are abutted in a stopped state. A raising / lowering member that has an abutting portion and is arranged at a conveyance end portion of the document placement surface and protrudes from the document placement surface in a state where the document conveyance portion is opened, The lifting member is closed when the original conveying unit is closed. Lowered by the transport section, the abutting portion is positioned below the document placing surface, and characterized in that.

  An image forming apparatus of the present invention includes an image reading device that reads a document, and an image forming unit that forms an image on a sheet based on image information read by the image reading device, and the image reading device includes It is characterized by being an image reading apparatus.

  In the image reading apparatus according to the present invention, the document placed on the document placement surface is positioned by the abutting portion of the elevating member at the end of the document placement surface where the document is fed by the document conveying portion. Yes.

  For this reason, in the image reading apparatus of the present invention, the reading unit stops when reading the document conveyed to the document placement surface and reads the document placed on the document placement surface while moving the document. The position to be the base point can be made the same position.

  Therefore, the image reading apparatus of the present invention can shorten the time for switching between the flow reading and the fixed reading, and can perform image reading promptly.

  Since the image forming apparatus of the present invention includes the image reading apparatus in which the time for switching between the continuous reading and the fixed reading is shortened, the time during which the read image information from the image reading apparatus is interrupted is shortened, and the unit It is possible to increase the number of sheets on which images are formed per hour.

FIG. 2 is a schematic cross-sectional view along the sheet conveying direction of the image forming apparatus according to the embodiment of the present invention. FIG. 3 is a cross-sectional view of the image reading apparatus according to the embodiment of the present invention along the document conveyance direction. FIG. 4 is an enlarged view of the periphery of an upstream read head and a downstream read head. It is a top view of the white guide plate of FIG. 2 and its peripheral part. It is a figure which shows the position of the white guide plate when a document is scanned and read. It is a figure which shows the position of a white guide plate when a document is fixedly read. It is a top view of the jump stand of FIG. 2 and its periphery. It is a figure which shows the position of the jump stand when the platen glass is opened in the document conveying section or when the document is fixedly read. It is a figure which shows the position of the jump stand when a document is scanned. It is a figure which shows the position of a jump stand and a white guide plate based on the detection operation of an open / close detection sensor and a placed document detection sensor. FIG. 5 is a view in which a jumping table is lowered by being pushed by a document conveying unit. It is an external appearance perspective view of the jump stand of FIG. FIG. 6 is a view in which a jumping base is released from being pressed by a document conveying unit and is raised.

  Hereinafter, an image reading apparatus according to an embodiment of the present invention and an image forming apparatus including the image reading apparatus in an apparatus body will be described with reference to the drawings.

(Image forming device)
FIG. 1 is a schematic cross-sectional view along the sheet conveying direction of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 100 includes an apparatus main body 100A and an image reading apparatus 1 provided on the upper part of the apparatus main body 100A. The detailed configuration and operation of the image reading apparatus 1 will be described later.

  The image reading apparatus 1 optically reads the document D and sends the image information to the laser scanner 102 as a digital signal. The apparatus main body 100A is configured to copy a document on a sheet such as plain paper or an OHP sheet based on image information from the image reading apparatus 1. The apparatus main body 100A can also form image information sent from an external facsimile or personal computer on a sheet.

  A plurality of sheet cassettes 104 (only one is shown in the figure and the others are omitted) that store sheets P of various sizes are mounted on the lower part of the apparatus main body 100A of the image forming apparatus 100. The sheet conveyed from the sheet cassette 104 by the conveying roller pair 105 is sent to the photosensitive drum 110 of the image forming unit 103. The photosensitive drum 110 is irradiated with the laser of the laser scanner 102 to form a latent image, and the latent image is developed with toner and formed in advance as a toner image. The toner image is transferred to the sheet and fixed on the sheet by the fixing device 106.

  When an image is formed on one side and it is not necessary to form both sides, the sheet is discharged to the in-body discharge tray 120 by the discharge roller pair 109. When images need to be formed on both sides, the sheet is turned over by switchback conveyance, conveyed through the retransmission path 107, and sent again to the image forming unit 103. In the image forming unit 103, the toner image is transferred to the other side of the sheet, the toner image is fixed by the fixing device 106, and is discharged from the discharge roller pair 109 to the in-body discharge tray 120.

  Note that the image forming apparatus 100 can transport sheets not only from the sheet cassette 104 but also from the multi-tray 108.

(Image reading apparatus 1)
FIG. 2 is a cross-sectional view of the image reading apparatus 1 according to the embodiment of the present invention along the document conveyance direction. FIG. 3 is an enlarged view of the periphery of the upstream read head 5 and the downstream read head 6.

  The image reading apparatus 1 includes a document conveying unit 50, a document placing unit 60, an upstream reading head 5, a downstream reading head 6 as a reading unit, and a jump table 61 that can be moved up and down as a lifting member.

  The document placing portion 60 has a platen glass 17 as a document placing surface on which a document is placed. The document conveying unit 50 is provided on the document placing unit 60 so that the platen glass 17 can be opened and closed. With the platen glass 17 closed, the document conveying unit 50 is moved from the intermediate side to the downstream end side of the platen glass 17 (FIG. 2). The document is conveyed toward the camera. 1, the front side of the paper surface is the front side in FIG. 1, and when this front side is lifted upward, the top side 17c of the platen glass 17 is rotated by rotating the front side hinge mechanism 51 as a fulcrum. It is designed to be opened.

  The image reading apparatus 1 includes two reading units positioned in the middle of a document conveyance path 4 that guides a document from a document stacking tray 2 on which a document is stacked by a user to a document discharge tray 3 from which the document whose image has been read is discharged. Both sides of the original are read by the heads 5 and 6. In this way, a method of feeding a document to the platen glass 17 and reading the document is referred to as “flowing scanning”.

  Further, the image reading apparatus 1 moves the downstream reading head 6 in the direction of arrow C from the position of the solid line shown in FIG. 2 to the position of the broken line under the platen glass 17 to place and fix the document on the platen glass 17. The document can be read. A reading method in which a document is placed on the platen glass 17 and the document is fixed is referred to as “fixed reading”.

  The document conveying unit 50 of the image reading apparatus 1 will be described.

  The document transport unit 50 includes a document transport path 4. A pickup roller 7 and a separation roller pair 8 are disposed at the upstream end of the document transport path 4 to transport the documents stacked on the document stacking tray 2 to the document transport path 4 one by one. A discharge roller pair 9 is disposed at the downstream end of the document transport path 4 to discharge the document transported through the document transport path 4 to the document discharge tray 3.

  The upstream reading head 5 receives the light emitted from the LED serving as the light emission source and reflected by the original with a 1 × contact image sensor (CIS sensor) or a CCD sensor, and reads the image of the original as image data. It has become.

  A position facing the upstream reading head 5 is an upstream reading position A. A guide member 22 (FIG. 3) that guides the document so that the document is conveyed at a predetermined interval with respect to the upstream read head 5 is slightly upstream of the upstream reading position A. It is provided on the side. On the downstream side of the separation roller pair 8, a conveyance roller pair 10 that conveys the originals separated one by one by the separation roller pair 8 is provided. In the document conveyance path 4 between the conveyance roller pair 10 and the upstream reading position A, a curved portion 14 is formed that is curved in a convex direction in the upper left direction in FIG. A pair of conveying rollers 13 for conveying the document toward the downstream reading position B described later is disposed in the document conveying path 4 on the downstream side of the upstream reading position A. A standard white plate 25 used for shading correction is provided at the lower part of the document conveying path 4 on the downstream side of the conveying roller pair 13 so as to contact the platen glass 17. A curved portion 12 is formed in the document conveyance path 4 from the upstream reading position A to the guide member 23 and the standard white plate 25 so that the document can be guided along the platen glass 17.

  A portion of the document conveyance path 4 facing a downstream reading position B described later is cut. The white guide plate 67 shown in FIGS. 3 to 6 is located in the cut portion. The white guide plate 67 is provided in the document conveying section 50 so that the intermediate portion protrudes downward and the upstream end and the downstream end are warped upward. The white guide plate 67 as the document pressing member can be moved up and down by a rack 67a and a pinion 71 with respect to the surface of the downstream end portion 17b as the transport end portion of the platen glass in the document transport direction. . The pinion 71 is rotated by a guide plate motor 73 around a support shaft 72 that is rotatably provided in the document conveying section 50. The rotational force of the guide plate motor 73 is transmitted to the pinion 71 via the output gear 74, the toothed belt 75, and the driven gear 76 shown in FIG. The rack 67a, the pinion 71, the guide plate motor 73, and the like constitute a guide plate elevating unit 80 as a pressing drive unit that elevates and lowers the white guide plate 67.

  The guide plate elevating unit 80 detects that a document is loaded on the document stacking tray 2 by a stacked document detection sensor 68 (described later), and when the image reading apparatus 1 reads and reads the document, the white guide plate 67 and the platen A gap G (FIG. 5) is formed with the glass 17. For this reason, the white guide plate 67 can guide the document passing over the downstream end portion 17b of the platen glass 17 so that it does not float from the platen glass 17 during the flow reading.

  The guide plate lifting / lowering unit 80 detects that a document is placed on the platen glass by a placed document detection sensor 66 (to be described later), and when the image reading apparatus 1 reads and reads the document, the white guide plate 67. The document is pressed against the platen glass 17 (FIG. 6). For this reason, the white guide plate 67 can prevent the document from floating on the platen glass and misalignment during fixed reading.

  As described above, the image reading apparatus 1 prevents the document D from being lifted from the platen glass 17 when the white guide plate 67 is used for both the flow reading and the fixed reading. Can be improved.

  The white guide plate 67 may be moved up and down by a plunger instead of the guide plate motor 73.

  The document conveyance path 4 on the downstream side of the white guide plate 67 is curved upward toward the document discharge tray 3, and a conveyance roller pair 11 is provided in the middle thereof.

  The document transport unit 50 can open and close the platen glass 17. For this reason, the document conveying section 50 has an elastic white pressure plate 18 on the lower side via an elastic document pressing member 19 in order to bring the document placed on the platen glass 17 into close contact with the platen glass 17. Is provided. The left end of the white pressure plate 18 is located near the conveying roller pair 13, and the right end is located at the right end of the document placing portion 60 so as to cover most of the platen glass 17.

  Opening / closing of the document conveying section 50 is detected by an opening / closing detection sensor 70 (FIG. 2) as an opening / closing detecting means provided in the document conveying section 50. Note that the open / close detection sensor 70 may be provided in the document placing portion 60. That is, the open / close detection sensor 70 only needs to be provided in at least one of the document conveying unit 50 and the document placing unit 60.

  The document transport unit 50 includes a placed document detection sensor 66 as a placed document detection unit that detects whether or not a document is placed on the platen glass 17 with the platen glass 17 closed. The document pressing member 19 (FIG. 3) provided with the placed document detection sensor 66 and the white pressure plate 18 are formed with a light transmission hole 66a for allowing the detection light of the placed document detection sensor 66 to reach the platen glass 17. Has been.

  The document transport unit 50 also includes a stacked document detection sensor 68 as a stacked document detection unit that detects whether or not documents are stacked on the document stacking tray 2. A light transmission hole 68 a for allowing the detection light of the stacked document detection sensor 68 to reach the document D on the document stacking tray 2 is formed in the document transport unit 50 provided with the stacked document detection sensor 68.

  The document placing unit 60 of the image reading apparatus 1 will be described.

  The document placing portion 60 has a platen glass 17 at the top. The platen glass 17 is provided so as to almost cover the upper part of the document placing portion 60.

  Below the platen glass 17 (FIG. 3), the downstream reading head 6 is provided so as to be movable in the left-right direction of FIG. 1 and FIG. 2 (document conveying direction of the document conveying unit 50) with the guide shaft 69 as a guide. . The downstream reading head 6 is located immediately below the platen glass when the document transport unit 50 transports the document from the intermediate part 17a side to the end part 17b side of the platen glass 17 with the platen glass 17 closed. Stopped at home position. FIG. 3 is a view when the downstream read head 6 is stopped at the home position. The portion of the platen glass 17 that faces the downstream reading head 6 when stopped at the home position, that is, the end 17 b is the downstream reading position B. Further, the white guide plate 67 is opposed to this position.

  The downstream reading head 6 (FIG. 1) sends the light emitted from the light emitter 91 and reflected by the original to the lens 95 via the reflectors 92, 93, 94. The reflected light sent to the lens 95 is converted into an electrical signal by the photoelectric conversion element 96 and sent to the laser scanner 102 as an image signal.

  When the original is placed on the platen glass 17 by the user, the downstream reading head 6 reads the original while moving from the downstream downstream reading position B of the solid line in FIG. It returns to the downstream reading position B. This reading method is fixed reading in order to read a document fixed to the platen glass 17. Note that the direction of arrow C in FIG. 2 is the sub-scanning direction when reading a document.

  Further, when no original is placed on the platen glass 17, the downstream reading head 6 reads the original conveyed to the platen glass 17 by the original conveying unit 50 in a state where the movement is stopped at the downstream reading position B. Yes. This reading is a flow reading because the document is conveyed to the platen glass 17.

  As described above, the downstream reading head 6 reads the original while moving from the downstream reading position B to the position of the broken line at the right end in FIG. 2 during the fixed reading, and stops moving to the downstream reading position B during the flow reading. The document is read with.

  As shown in FIGS. 3 and 7 to 9, a jump base 61 that moves up and down along the end 17 b is disposed at the end 17 b of the platen glass 17. The jump base 61 is moved up and down by a pinion 64 meshing with a rack 61a formed on the jump base 61 and the pinion 64 being rotated by a jump base motor 62 (FIG. 7). The pinion 64 is provided on a support shaft 65 that is rotatably provided on the document placement unit 60. The pinion 64 is moved up and down to transmit the rotational force of the jump table motor 62 through the output gear 63. It is designed to rotate. The rack 61a, the pinion 64, the jumping table motor 62, and the like constitute a jumping table lifting / lowering unit 81 as lifting / lowering driving means for lifting and lowering the jumping table.

  Further, the jumping table 61 has a stopper 61b that functions to receive a document placed on the platen glass 17 in a state where the jumping table 61 is raised and protrudes from the platen glass 17 as shown in FIG. Further, the jump table 61 has a function of guiding the document conveyed to the platen glass 17 by the document conveying unit 50 from the platen glass 17 to the inside of the document conveying unit 50 in the lowered state as shown in FIG. have. That is, the guide 61c guides the document from the platen glass 17 in the discharge direction.

  Further, in the lowered state, the jump base 61 is positioned such that the stopper 61b and the document guide start end 61d of the guide 61c are equal to or lower than the platen glass 17 (preferably lower than the platen glass 17). It is like that. As a result, when the document to be scanned is conveyed from the platen glass 17 to the guide 61c of the jump table 61, it can be prevented from coming into contact with the stopper 61b of the jump table 61 and being jammed.

  The jump table 61 may be moved up and down by a plunger instead of the jump table motor 62.

  The image reading apparatus 1 operates under the control of the CPU 130 as a control unit. As shown in FIG. 1, the CPU 130 includes a guide plate motor 73 that raises and lowers the white guide plate 67, a jump table motor 62 that raises and lowers the jump table 61, a placed document detection sensor 66, a loaded document detection sensor 68, and an open / close detection sensor. 70 etc. are connected.

  The operation of the image reading apparatus 1 will be described.

  When the document transport unit 50 is raised by the user and the platen glass 17 is released (see the column in FIG. 10A), the open / close detection sensor 70 does not detect the document placement unit 60. (OFF). Further, even if a document is placed on the platen glass, the placed document detection sensor 66 is not detected (OFF) because it is separated from the platen glass. In this case, the CPU 130 operates the jump table motor 62 so that the stopper 61b protrudes above the upper surface 17c of the platen glass 17 as shown in FIG. Further, the CPU 130 operates the guide plate motor 73 so that the white guide plate 67 is located at a position where a gap G can be opened between the white guide plate 67 and the platen glass 17 as shown in FIG. That is, the CPU 130 holds the jump base 61 and the white guide plate 67 at the raised position.

  The operation of the flow reading will be described.

  In the case of flow reading (see the column of FIG. 10B), the platen glass 17 is closed by the document conveying unit 50 in a state where no document is placed on the platen glass 17. In this state, the open / close detection sensor 70 detects the document placing portion 60 and detects that the platen glass is closed (ON). Further, the detection light of the placed original detection sensor 66 passes through the light transmission hole 66 a and also passes through the platen glass 17 because no original is placed on the platen glass 17. For this reason, the placed document detection sensor 66 is in an OFF state. In this case, the CPU 130 lowers the jump base 61 from the home position shown in FIG. 8 to a position where the stopper 61b is equal to or lower than the upper surface 17c of the platen glass 17 as shown in FIG. However, the CPU 130 does not operate the guide plate motor 73. For this reason, as shown in FIG. 5, the white guide plate 67 is held at a raised position with a gap G between the white guide plate 67 and the platen glass 17.

  In this state, when a document is stacked on the document stacking tray 2, the detection light of the stacked document detection sensor 68 is reflected by the document stacked on the document stacking tray 2 through the light transmission hole 68 a. For this reason, the loaded document detection sensor 68 detects that a document is stacked on the document stacking tray 2 and changes from OFF to ON, so the CPU 130 operates the image reading apparatus. Then, the document loaded on the document stacking tray 2 is supplied to the document transport path 4 by the pickup roller 7 and is prevented from being double-fed by the separation roller pair 8 (the documents are fed in a superimposed manner), and only one sheet downstream. It is conveyed to the side. Then, the original is given a conveying force by the conveying roller pair 10 and is conveyed to the upstream reading position A through the original conveying path 4 in the bending portion 14. The conveyance roller pair 10, the curved portion 14, and the guide member 22 are arranged in this order on the upstream side of the upstream reading position A in the document conveyance direction. For this reason, the document passing through the upstream reading position A is always conveyed along the position separated from the upper inner wall surface of the document conveying path 4 by a certain distance at the upstream reading position A. In addition, the upstream reading head 5 can be focused on the document, and the upstream reading head 5 can accurately read the image on the first surface of the document, thereby improving the reading accuracy of the image data.

  The document from which the image on the first surface has been read at the upstream reading position A is given conveyance force by the conveyance roller pair 13, and further downstream while contacting the lower inner wall surface of the document conveyance path 4 at the curved portion 12. It is conveyed toward. A pair of conveyance rollers 13, a curved portion 12, and a guide member 23 are arranged in this order on the upstream side of the downstream reading position B in the document conveyance direction. For this reason, the document passing through the downstream reading position B is always transported along the position at a certain distance from the lower inner wall surface in the document transporting path 4 at the downstream reading position B. In addition, the downstream reading head 6 stopped at the downstream reading position B can be focused on the original, and the reading of the image on the second surface of the original by the downstream reading head 6 becomes accurate, and the image data is read. Accuracy can be increased.

  Since the image reading apparatus 1 performs the shading correction by arranging the standard white plates 24 and 25 for the upstream reading head 5 and the downstream reading head 6, respectively, high-quality image data on both the front and back sides of the document. Can be obtained.

  The document that has passed over the downstream reading head 6 passes through the jump table 61. At this time, as shown in FIGS. 3 and 9, the jump base 61 is located at a position where the stopper 61 b is lower than the upper surface 17 c of the platen glass 17. For this reason, the document is turned up from the curved portion 12 of the document conveyance path 4 into the document conveyance unit while being scooped up by the jump guide 61c without coming into contact with the stopper 61b. Be transported. Finally, the document is discharged to the document discharge tray 3 by the discharge roller pair 9.

  The operation of fixed reading will be described.

  In the case of fixed reading, first, the document conveying unit 50 is raised and the platen glass 17 is released by the user (see the column of FIG. 10A), and the open / close detection sensor 70 is connected to the document placing unit 60. Is not detected (OFF). The placed document detection sensor 66 has a document placed on the platen glass, but is away from the platen glass, so that nothing is detected (OFF). In this case, the CPU 130 operates the jump table motor 62 so that the stopper 61b protrudes above the upper surface 17c of the platen glass 17 as shown in FIG. Further, the CPU 130 operates the guide plate motor 73 so that the white guide plate 67 is located at a position where a gap G can be opened between the white guide plate 67 and the platen glass 17 as shown in FIG. That is, the CPU 130 holds the jump base 61 and the white guide plate 67 at the raised position.

  In this state, the user places a document on the platen glass 17. The document is abutted against a stopper 61b as an abutting portion of the jump stand and positioned. At this time, the document is also abutted against the frame 20 (FIG. 7) of the platen glass 17. The stopper 61b and the frame 20 are arranged at right angles to each other.

  Since the image reading apparatus places a document on the platen glass 17 during fixed reading, when the platen glass is opened, the jumper stopper 61b protrudes above the upper surface 17c of the platen glass. Positioning can be performed.

  Thereafter, the user closes the platen glass 17 with the document conveying section 50 (see the column of FIG. 10 (3)). Then, the open / close detection sensor 70 detects the document placing portion 60 and detects that the platen glass is closed (ON). Further, the detection light of the placed document detection sensor 66 passes through the light transmission hole 66 a and is reflected by the document placed on the platen glass 17. Therefore, the placed document detection sensor 66 detects the document and changes from OFF to ON. The CPU 130 holds the jump stand 61 in the raised position, but operates the guide plate motor 73 to lower the white guide plate 67 and presses the document against the end portion 17 b of the platen glass with the white guide plate 67. . In this case, the jump base 61 that has been raised and the white guide plate 67 that has been lowered are formed in a shape that does not interfere with each other.

  Thereafter, the user presses the start button on the operation panel 111 of the image forming apparatus 100. Then, the CPU 130 operates a drive source (not shown) of the downstream reading head 6 to move the downstream reading head 6 from the position of the solid line in FIG. 2 to the position of the broken line (in the direction of arrow C) according to the size of the document. Move only the length. During this time, the downstream reading head 6 reads the document placed on the platen glass 17.

  As described above, the downstream read head 6 is the same as the base point at which movement starts in the fixed reading and the stop position in the flow reading, and changes from the flow reading to the fixed reading or from the fixed reading to the flow reading. When changing, there is no need to change position. Therefore, the image reading apparatus 1 can shorten the time for switching between the flow reading and the fixed reading, and can quickly perform the image reading.

  Further, since the white guide plate 67 presses the document against the end portion 17b of the platen glass, the edge of the document does not turn up, and the downstream reading head 6 can improve the reading accuracy from the edge of the document. it can.

  In the above description, the white guide plate 67 is lowered during fixed reading and presses the document against the platen glass 17. However, the white guide plate 67 may be fixed at a position where the gap G is held, and does not necessarily move up and down. There is no need to be.

  In the image reading apparatus 1 described above, the motor is operated based on the detection operation of the sensor to raise and lower the jump table. However, in the image forming apparatus 200 described below, the opening / closing operation of the document conveying unit 250 and the spring 280 The jumping platform is moved up and down by the elasticity of.

  In FIG. 11, the image reading apparatus 201 of the image forming apparatus 200 is different from the image reading apparatus 1 of FIGS. For this reason, the periphery of the jumping base 261 will be described, and the description and illustration of other parts will be omitted.

  The jumping table 261 moves up and down with a long hole 270 formed between the end portion 17b of the platen glass 17 of the document placing portion 260 and the frame 260A of the document placing portion 260 as a guide. The long hole 270 is formed along the main scanning direction that intersects the document conveyance direction (arrow E direction). The jump base 261 is also formed with a stopper 261b and a guide 261c.

  As shown in FIG. 12, the jump base 261 integrally has a storage portion 281 for storing a spring 280 as an elastic member that applies a rising force to the jump base 261 at both ends. The storage unit 281 is located on both sides of the document passage area so as not to interfere with the document passage.

  A projection 205 is provided on the document conveyance path 204 of the document conveyance unit 250 so as to protrude downward when the document conveyance unit 250 closes the platen glass 17. The projection 205 contacts the head 281 a of the storage unit 281. The protrusion 205 is located on the upstream side of the transport roller pair 11. The spring 280, the protrusion 205, and the like constitute a jump base elevating part 282.

  In such a configuration, as shown in FIG. 11, when the platen glass 17 is closed by the document conveying unit 250, the protrusion 205 comes into contact with the head 281 a of the storage unit 281 and resists the spring 280 and the storage unit 281 and The jump stand 261 is pushed down.

  In such a configuration, when the document conveying section 250 is raised and the platen glass 17 is released by the user (FIG. 13), the jump base 261 is pushed up by the spring 280, and the document guide start end 261d is made of the platen glass. Projects upward from the upper surface 17c. For this reason, a part of the stopper 261b of the jump stand protrudes above the upper surface 17c of the platen glass.

  When the platen glass 17 is closed by the document conveying unit 250 from the state shown in FIG. 13, the projection 205 presses the head 281 a of the storage unit 281. Then, the jumping table 261 moves down against the spring 280, and the stopper 261b and the document guide start end portion 261d of the guide 261c are equal to or less than the same height as the platen glass 17 (preferably lower than the platen glass 17). To the position shown in FIG.

  In the case of fixed reading, as shown in FIG. 13, the document conveying section 250 is raised by the user, the platen glass 17 is released, and a part of the jump table stopper 261b protrudes above the upper surface 17c of the platen glass. Then, the original is brought into contact with the stopper 261b. As a result, the document is positioned on the platen glass 17.

  Then, when the platen glass 17 is closed by the document conveying section 250, the jump base 261 is pushed down by the protrusion 205 as shown in FIG. At this time, since the original is pressed against the upper surface 17c of the platen glass by the white pressure plate 18 shown in FIG. 3, the position is hardly shifted. Thereafter, the downstream reading head 6 shown in FIG. 2 reads the document while moving from the position shown in FIG. 2 to a position corresponding to the size of the document in the direction of arrow C.

  As described above, the image reading apparatus 201 reads the document positioned on the stopper 261b as the abutting portion, and thus the reading accuracy can be improved.

  In the case of scanning, as shown in FIG. 11, the platen glass is closed by the document conveying unit, and the jumping roller 261 is lowered, and the conveying roller pair 13 and 11 causes the document to move on the end 17b of the platen glass. Let it pass. At this time, as shown in FIG. 11, since the stopper 261b is located at a position lower than the upper surface 17c of the platen glass 17, the document is conveyed while being scooped up by the guide 261c of the jump table without coming into contact with the stopper 261b. Is done. That is, the guide 261 c guides the document in the direction of discharging from the platen glass 17. In this state, the downstream reading head 6 reads the document at the downstream reading position B.

  Also in the image reading apparatus 201 described above, the downstream reading head is the same as the starting point of movement at the time of fixed reading and the stop position at the time of flow reading. There is no need to change the position when changing from to non-scanning. Therefore, the image reading apparatus 201 can shorten the switching time between the flow reading and the fixed reading, and can perform the image reading promptly.

  Further, since the image forming apparatus includes an image reading apparatus that shortens the switching time between the continuous reading and the fixed reading, the time when the read image information from the image reading apparatus is interrupted is reduced, and the unit time per unit time is reduced. The number of sheets on which images can be formed can be increased.

1: image reading device, 2: document stacking tray, 3: document discharge tray, 5: upstream reading head, 6: downstream reading head (reading unit), 17: platen glass (document placing surface), 17a: platen glass Intermediate part, 17b: end of platen glass (conveying end), 17c: upper surface of platen glass 17, 18: white pressure plate (original pressing plate), 50: original conveying part, 60: original placing part, 61: jump Stand (lifting member), 61b: jump stand stopper (butting portion), 61c: jump stand guide, 61d: jump guide original guide end portion, 66: placed document detection sensor (placed document detection means), 67: White guide plate (document pressing member), 80: Guide plate lifting / lowering unit (pressing drive means), 68: Stacked document detection sensor (stacked document detection means), 70: Open / close detection sensor (open / close detection means), 81: Camp stand elevating unit (elevating drive means) 100: image forming apparatus, 100A: apparatus main body, 103: image forming unit, 130: CPU, 200: image forming apparatus, 201: image reading apparatus, 205: protrusion, 250: document conveyance , 260: Document placement unit, 261: Jump table (lifting member), 261b: Jump table stopper (butting unit), 261c: Jump table guide, 261d: Document guide start end of jump table, 280: Spring (Elastic member), 282: Jump stand elevating part,
A: upstream reading position, B: downstream reading position, C: arrow, D: document, E: document transport direction, P: sheet.

Claims (10)

A document placement portion having a document placement surface on which a document is placed;
A document conveying section that is openable and closable with respect to the document placing surface and conveys the document toward the document placing surface in a closed state;
When an original is placed on the original placement surface, the original placed on the original placement surface is read while moving, and when the original transport unit is transporting the original, stop. In such a state, a reading unit that reads a document conveyed to the document placement surface by the document conveyance unit;
The document placement unit has an abutting portion against which the document placed on the document placement surface is abutted, and is disposed at a conveyance end of the document placement surface, and the document conveyance unit is opened. An elevating and lowering member protruding from the surface,
The elevating member is lowered by the closed document conveying portion when the document conveying portion is closed, and the abutting portion is positioned below the document placing surface.
An image reading apparatus. The elevating member located below has a guide that guides the document transported to the document placement surface by the document transport unit in a direction to be transported from the document placement surface and discharged.
In the state where the elevating member is lowered, the document guide start end portion of the guide is positioned lower than the document placement surface.
The image reading apparatus according to claim 1. Open / close detection means of the document conveying section;
Elevating drive means for raising and lowering the elevating member,
The elevating drive means raises the elevating member to a position protruding from the original placing surface when the open / close detecting means detects that the original conveying section is released.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. A placed document detecting means for detecting whether or not a document is placed on the document placing surface;
Elevating drive means for raising and lowering the elevating member,
The elevating and lowering drive means is located at a position where the elevating member can guide the document in the direction of conveying and ejecting the original from the original placing surface when the placed original detecting means does not detect the original. Down,
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. A stacked document detection means for detecting whether or not a document is stacked on the document transport unit;
Elevating drive means for raising and lowering the elevating member,
The elevating drive unit lowers the elevating member to a position where the elevating member can guide the document in the direction of conveying and ejecting the document from the document placing surface when the stacked document detecting unit detects the document. ,
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. An elastic member for applying a lifting force to the elevating member;
The elevating member is raised by the elastic member when the document conveying unit is opened, and is lowered against the elastic member by being pressed by the document conveying unit when the document conveying unit is closed.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus.   6. A document pressing member capable of coming into contact with and separating from the downstream end surface of the document placement surface in the document transport direction and pressing the surface of the downstream end portion of the document. The image reading apparatus according to any one of the above. A document pressing member that is capable of coming into contact with and separating from the downstream end surface of the document placement surface in the document transport direction and presses the downstream end surface of the document; and a pressing drive unit that raises and lowers the document pressing member. With
The pressing driving means lowers the original pressing member to a position where the original pressing member can press the original on the original placing surface when the original detecting means detects the original.
The image reading apparatus according to claim 4, wherein the image reading apparatus is an image reading apparatus. A document pressing member that is capable of coming into contact with and separating from the downstream end surface of the document placement surface in the document transport direction and presses the downstream end surface of the document; and a pressing drive unit that raises and lowers the document pressing member. With
A pressure driving unit that, when the stacked document detection unit detects a document, raises the document pressing member to a position where the document of the document transport unit can be guided in a direction in which the document is discharged from the document placement surface;
The image reading apparatus according to claim 5, wherein the image reading apparatus is an image reading apparatus. An image reading device for reading an original;
An image forming unit that forms an image on a sheet based on image information read by the image reading device;
The image reading apparatus is the image reading apparatus according to any one of claims 1 to 9.
An image forming apparatus.

Images