JP2009044521A - Image reading apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the external shape of an image reading apparatus by positioning an image reading unit in the image reading range of a medium placing section by installing a shutter that covers the image reading unit freely openably and closably. <P>SOLUTION: The image reading apparatus comprises an image reading unit for reading the image of a document, a scanning mechanism for using the image reading unit for scanning to read the image of the document placed on the medium placing section, a document feeding mechanism which is arranged above the scanning mechanism and feeds the document by conveying it to the image reading unit, and a shutter that covers the image reading unit freely openably and closably. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image reading apparatus and an image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine, a facsimile machine, or a multi function printer (MFP) has an image reading device that reads an image of a document. The image reading apparatus includes a medium feeding device (ADF: Auto Document Feeder) that separates and transports a set of a plurality of original documents one by one and a medium conveyed by the medium feeding device. A scanner for reading the image. The scanner can also read an image of a medium placed on a flat bed (see, for example, Patent Document 1).

The scanner uses a single reading sensor to read both an image of the medium conveyed by the medium feeding device and an image of the medium placed on the flat bed. When reading an image of a medium placed on the flat bed, it is necessary to press the medium against the reading surface of the flat bed using a uniform document pressing plate. Therefore, when reading the image of the medium conveyed by the medium feeding device, it is necessary to position the reading sensor outside the image reading range on the flat bed.
JP 2001-242670 A

  However, in the conventional image reading apparatus, when the image of the medium conveyed by the medium feeding apparatus is read, the reading sensor is positioned outside the image reading range on the flat bed. The outer shape of will become larger.

  The present invention solves the problems of the conventional image reading apparatus and disposes the image reading unit within the image reading range of the medium mounting unit by disposing a shutter unit that covers the image reading unit so as to be freely opened and closed. An object of the present invention is to provide an image reading apparatus and an image forming apparatus capable of reducing the outer shape of the image reading apparatus.

  Therefore, in the image reading apparatus of the present invention, an image reading unit that reads an image of a document, a scanning mechanism that scans the image reading unit to read an image of a document placed on a medium placement unit, A document feeding mechanism that is disposed above the scanning mechanism and that transports a document and supplies the document to the image reading unit, and a shutter unit that covers the image reading unit so as to be freely opened and closed.

  According to the present invention, in the image reading apparatus, the image reading unit is positioned within the image reading range of the medium placing unit by disposing the shutter unit that covers the image reading unit so as to be freely opened and closed. The outer shape can be reduced.

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

  FIG. 1 is a diagram showing the configuration of the image forming apparatus according to the first embodiment of the present invention.

  As shown in the figure, the image forming apparatus according to the present embodiment includes an image forming unit 1 and an image reading unit 13 as an image reading apparatus. The image forming apparatus is, for example, a copier, a facsimile machine, a multifunction machine commonly referred to as an MFP, and the like. The image forming unit 1 prints an image on a medium such as paper, and an image of a document that is a medium such as paper. Any type of apparatus may be used as long as the apparatus includes the image reading unit 13 that reads the image.

  The image forming unit 1 may form a monochrome image, may form a color image, or may form an image by any method such as an ink jet method or a thermal transfer method. Here, there are four image drum units that form images with toners of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K), and color images are formed by electrophotography. A case of a tandem type color electrophotographic printer that forms the image will be described.

  The image forming unit 1 includes a stacked cassette medium, a sheet feeding cassette unit 2 that supplies the medium one by one, and four image drum units that transfer toner images of each color onto the conveyed medium. It has an image forming unit 8 and a fixing unit 9 for fixing the transferred toner image to the medium.

  The paper feed cassette unit 2 is provided with a paper feed roller 3 that feeds the stacked media one by one from the top. The paper feed roller 3 incorporates a one-way crunch (not shown) that transmits a driving force from a driving source (not shown) only in one direction and idles when it is reversed.

  Further, the sensors 4 and 6 for detecting the passage of the medium along the medium conveyance path for conveying the medium from the paper feed cassette unit 2 to the image forming unit 8, and a function for correcting the skew of the fed medium. A conveying roller 5 for conveying, and a conveying roller 7 for feeding the medium conveyed from the conveying roller 5 to the image forming unit 8 are provided.

  In each image drum unit in the image forming unit 8, charging, exposure, development, and transfer processes are performed, and toner images of each color formed on the image drum are transferred to a medium by a transfer roller. Then, the medium onto which the toner image has been transferred passes between a heating roller and a pressure roller provided in the fixing unit 9, whereby the toner image is fixed on the medium.

  Further, discharge rollers 10 and 11 for sending the medium to the discharge tray 12 are disposed along the medium transport path for transporting the medium discharged from the fixing unit 9.

  The image reading unit 13 includes a medium feeding device 14 as a document feeding mechanism and a flat bed scanner 15, and is disposed above the image forming unit 1.

  The medium feeding device 14 is a device commonly referred to as ADF that separates and conveys a set of a plurality of documents as originals one by one and supplies them to the flatbed scanner 15. The flat bed scanner 15 includes a medium loading plate 20 as a flat bed that is a medium loading portion on which a medium is loaded, and a medium pressing plate that presses the medium loaded on the medium loading plate 20. 21 and a sensor carriage 16 serving as a scanning mechanism disposed below the flat bed, and an apparatus for reading an image of a medium placed on the flat bed. The medium mounting plate 20 is made of a light-transmitting plate material such as a glass plate, and the medium pressing plate 21 is a light-reflecting white sheet that is attached to the lower surface, that is, the medium contact surface. Is provided.

  Further, the image reading unit 13 is disposed at both ends in the width direction of the paper feed tray 17 for placing the medium, and in the width direction of the medium placed on the paper feed tray 17. A pair of guide units 18 for guiding both ends, and a discharge tray 19 on which a medium discharged after image reading is placed are provided. The guide unit 18 prevents the skew of the medium.

  Next, the configuration of the image reading unit 13 will be described in detail.

  FIG. 2 is a first cross-sectional view showing the configuration of the main part of the image reading unit in the first embodiment of the present invention, and FIG. 3 is the configuration of the main part of the image reading unit in the first embodiment of the present invention. It is the 2nd sectional view showing.

  The sensor carriage 16 includes an image reading sensor unit 24 as an image reading unit disposed on the upper surface, and is movable in the horizontal direction in the drawing, that is, in the horizontal direction along the guide member 16a. The image reading sensor unit 24 includes a sensor such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor), an optical element such as a lens and a light guide member, and the like, and reads an image on a medium. Yes.

  When the medium is supplied to the flat bed scanner 15 by the medium feeding device 14, the sensor carriage 16 stops at a position as shown in FIG. 2 and stops together with the sensor carriage 16. Reads an image of a relatively moving medium. When the medium is placed on the medium placement plate 20, the sensor carriage 16 moves at a constant speed in the direction indicated by the arrow C and moves with the sensor carriage 16 as shown in FIG. 3. The reading sensor unit 24 reads the image of the stopped medium.

  Reference numeral 28 denotes a hopper for aligning the leading ends of the media placed on the paper feed tray 17, which is moved up and down by the urging force of the spring 29. Reference numeral 22 denotes a paper feed roller for separating and transporting the media one by one. The separation pad 31 is brought into close contact with the paper feed roller 22 by the urging force of the spring 30. Further, the medium feeding device 14 includes a conveyance roller 23 for conveying the medium to the image reading sensor unit 24, a discharge roller 25 for discharging the medium after reading the image to the discharge tray 19, and a spring 26. A medium pressing member 27 is provided for pressing the medium at a position facing the image reading sensor unit 24 by the urging force. Reference numerals 35, 36, and 37 denote drive shafts for the paper feed roller 22, the transport roller 23, and the discharge roller 25, respectively.

  In the present embodiment, the medium feeding device 14 includes a shutter 33 as a shutter unit that covers an image reading unit so as to be freely opened and closed. The shutter 33 opens and closes a reading window 101. The window 101 is provided with a transparent guide 61. The transparent guide 61 is a transparent member such as a light-transmitting acrylic plate and also functions as a medium transport guide. The shutter 33 is moved in the horizontal direction in FIGS. 2 and 3, that is, in the horizontal direction by the gear 32 to open and close the window 101. Reference numeral 39 denotes a drive shaft of the gear 32.

  When the medium is supplied to the flat bed scanner 15 by the medium feeding device 14, the shutter 33 is opened and the window 101 is opened. The window 101 exists at a reading position, that is, a position facing the image reading sensor unit 24 in FIG. Accordingly, the image reading sensor unit 24 stopped together with the sensor carriage 16 can read the image of the medium passing through the window 101 through the transparent guide 61 of the window 101. The reading position, that is, the position where the image reading sensor unit 24 is stopped is within the image reading range of the medium placing plate 20. Further, the medium is conveyed between the transparent guide 61 and the medium pressing member 27. The medium pressing member 27 is urged in the direction of the transparent guide 61 by the urging force of the spring 26 and presses the medium against the transparent guide 61.

  The transparent guide 61 can be omitted. In this case, the window 101 exists as an opening.

  Further, when the medium is placed on the medium placing plate 20, the shutter 33 is in a closed state and is moved leftward in the drawing so as to cover the window 101 at the reading position. That is, the shutter 33 is moved to the left from the reading position, and the window 101 is covered with the shutter 33 as shown in FIG.

  Next, the configuration of the drive unit of the image reading unit 13 will be described.

  FIG. 4 is a first perspective view showing the configuration of the drive unit of the image reading unit in the first embodiment of the present invention, and FIG. 5 is the configuration of the drive unit of the image reading unit in the first embodiment of the present invention. FIG. 6 is a first perspective view showing the configuration of the medium pressing plate of the image reading unit in the first embodiment of the present invention, and FIG. 7 is the first embodiment of the present invention. FIG. 8 is a perspective view showing the configuration of the shutter of the image reading unit according to the first embodiment of the present invention.

  As shown in FIGS. 4 and 5, the drive shafts 35, 36 (FIG. 2), 37, and 39 are respectively attached to the base unit 43 of the image reading unit 13. The gear 32 for moving the shutter 33 includes a first gear 32 a and a second gear 32 b disposed on both sides in the width direction of the medium, and is fixed to the drive shaft 39. The shaft 28 a of the hopper 28 is also attached to the base unit 43.

  Further, the image reading unit 13 is attached to a drive motor 34 for driving the drive shafts 35, 36, 37 and 39, a lock member 38 connected to the drive shaft 35, a sensor 42 for detecting a medium, and a drive shaft 39. The torque limiter 40, the rib 43a of the base unit 43 in contact with the lock member 38, and the gears 44, 54, 55, 56, 57, 58, 59 and 60 are included.

  The sensor 42 detects the medium by pressing the medium. The gear 54 is a drive gear for driving the paper feed roller 22 and the lock member 38, and is connected to the drive shaft 35. Further, the gear 56 is a drive gear for driving the transport roller 23 and is connected to the drive shaft 36. Further, the gear 60 is a drive gear for driving the discharge roller 25 and is connected to the drive shaft 37.

  The gears 55, 57, 58 and 59 are driving force transmission gears for transmitting the driving force of the driving motor 34 to the gears 54, 56 and 60, and have a double gear structure. The gear 58 meshes with the drive motor 34 and the gears 57 and 59, and the gear 57 meshes with the gear 56. Further, the gear 59 is meshed with the gears 44, 55 and 60.

  When the medium is supplied to the flat bed scanner 15 by the medium feeding device 14, the drive motor 34 rotates in the direction indicated by the arrow F and the shutter 33 is indicated by the arrow A as shown in FIG. Move in the direction. Since the lock by the lock member 38 is released, the hopper 28 rotates in the direction indicated by the arrow G around the shaft 28a.

  On the other hand, when the medium is placed on the medium placement plate 20, the drive motor 34 rotates in the direction indicated by the arrow H and the shutter 33 moves in the direction indicated by the arrow B as shown in FIG. To do. Since the lock member 38 is locked, the hopper 28 rotates about the shaft 28a in the direction indicated by the arrow I.

  As shown in FIGS. 6 and 7, the image reading unit 13 has a cover 41 that covers the top of the medium placing plate 20, and long holes 41a and 41b are formed on both sides of the cover 41. Is formed. The shutter 33 is fitted into the long holes 41a and 41b. The shutter 33 is made of a plate material having a light-reflective white sheet pasted on the surface thereof, or a plastic plate material toned in white. As shown in FIG. 8, the shutter 33 includes posts 33a and 33b, and the posts 33a and 33b are slidable within the long holes 41a and 41b.

  The torque limiter 40 has a function of causing the gear 44 to idle when a torque exceeding a specified value is applied. The specified value needs to be a value equal to or greater than a torque necessary for opening and closing the shutter 33, and is, for example, 300 [g * cm].

  When the medium is supplied to the flat bed scanner 15 by the medium feeding device 14, the shutter 33 is opened and the transparent guide 61 is exposed as shown in FIG. On the other hand, when the medium is placed on the medium placing plate 20, as shown in FIG. 6, the shutter 33 is closed, and the transparent guide 61 of the window 101 is shielded.

  Next, the operation of the image printing apparatus having the above configuration will be described. First, the operation of the image forming unit 1 will be described.

  First, the medium set in the paper feed cassette unit 2 is fed out one by one by the paper feed roller 3 and conveyed to the image forming unit 8 by the conveyance rollers 5 and 7. Subsequently, a toner image is transferred to the medium by the image forming unit 8. Then, the medium on which the toner image is transferred is conveyed to the fixing unit 9. As the medium passes between a heating roller and a pressure roller provided in the fixing unit 9, the toner image is fixed on the medium. Then, the medium on which the toner image is fixed is discharged to the discharge tray 12 by the discharge rollers 10 and 11, and the image forming operation by the image forming unit 1 is completed.

  Next, the operation of the image reading unit 13 will be described. First, an operation when a medium is supplied by the medium feeding device 14 will be described.

  FIG. 9 is a time chart showing the operation of the image reading unit in the first embodiment of the present invention.

First, when the medium is placed on the paper feed tray 17, the sensor 42 detects the medium (Fig. 9: t _0). Subsequently, the user gives a reading instruction by, for example, pressing a start button (not shown) (FIG. 9: t _S ). Then, the drive motor 34 rotates in the direction indicated by the arrow F in FIG. Even if the reading instruction is given, if the medium is not placed on the paper feed tray 17, that is, if the sensor 42 does not detect the medium, the medium is placed on the medium placement plate 20. Since it is determined that the drive motor 34 has not been driven, the drive motor 34 does not rotate.

  When the drive motor 34 rotates, the gears 44, 54, 55, 56, 57, 58, 59 and 60 rotate in directions indicated by arrows in FIG. Then, the lock member 38 connected to the drive shaft 35 rotates in the same direction as the gear 54, and comes into contact with the rib 43 a of the base unit 43 and stops. As a result, the lock member 38 holding the hopper 28 is detached from the hopper 28, and the lock of the hopper 28 is released.

Further, simultaneously with the rotation of the lock member 38, the first gear 32a and the second gear 32b fixed to the drive shaft 39 rotate, so that the shutter 33 slides in the direction indicated by the arrow A in FIG. When the posts 33a and 33b of the shutter 33 come into contact with the end surfaces of the long holes 41a and 41b of the cover 41, a load is applied to the drive shaft 39. Therefore, the gear 44 is idled by the action of the torque limiter 40, and the first gear 32a. And the rotation of the second gear 32b stops. As a result, the shutter 33 stops sliding, and is opened as shown in FIG. 7, and the transparent guide 61 of the window 101 is exposed (FIG. 9: t ₁ ).

On the other hand, when the lock of the hopper 28 is released, the hopper 28 is rotated and set in the direction indicated by the arrow G around the shaft 28a by the biasing force of the spring 29 as shown in FIG. The medium is brought into close contact with the paper feed roller 22. Then, the medium is fed one by one from the paper feed tray 17 by the paper feed roller 22, and stopped at the reading position, that is, as shown in FIG. 2, by the transport roller 23 fixed to the drive shaft 36. The image reading sensor unit 24 is conveyed above. The medium conveyed above the image reading sensor unit 24 is pressed by the medium pressing member 27, pressed against the transparent guide 61 of the window 101, and image reading is started by the stopped image reading sensor unit 24. (FIG. 9: t ₂ ).

The medium from which the image has been read is discharged to the discharge tray 19 by the transport roller 25 fixed to the drive shaft 37. In this way, the medium set on the paper feed tray 17 is conveyed one by one and the image is read (FIG. 9: t _{2 to} t ₄ ).

When the medium placed on the paper feed tray 17 runs out, the sensor 42 returns to the position as shown in FIG. 5, and the detection of the medium by the sensor 42 is turned off (FIG. 9: t ₃ ).

Subsequently, when the last medium has passed the reading position, reading of the medium is completed (FIG. 9: t ₄ ). Thereafter, the rotation of the drive motor 34 is continued for a predetermined time, and when the last medium is discharged to the discharge tray 19, the rotation of the drive motor 34 is stopped (FIG. 9: t ₅ ).

Then, after stopping the rotation for a predetermined time, the drive motor 34 temporarily rotates in the reverse direction, that is, in the direction indicated by the arrow H in FIG. 5 (FIG. 9: t ₆ ). . As a result, the gears 44, 54, 55, 56, 57, 58, 59, and 60 rotate in directions indicated by arrows in FIG. Then, the lock member 38 connected to the drive shaft 35 rotates in the same direction as the gear 54, thereby rotating the hopper 28 in the direction indicated by the arrow I about the shaft 28a to push down and lock.

Further, simultaneously with the rotation of the lock member 38, the first gear 32a and the second gear 32b fixed to the drive shaft 39 rotate, so that the shutter 33 slides in the direction indicated by the arrow B in FIG. As shown in FIG. 6, the shutter 33 returns to the closed state, and the transparent guide 61 of the window 101 is shielded. Then, the drive motor 34 stops rotating (FIG. 9: t ₇ ).

  Next, the operation of the image reading unit 13 when a medium is placed on the medium placing plate 20 will be described.

  When the user places a medium on the medium placing plate 20, the sensor 42 does not detect the medium, so that the image reading unit 13 is in a state where the shutter 33 is closed as shown in FIGS. It has become.

  Subsequently, when the user gives a reading instruction by, for example, pressing a start button (not shown), the sensor carriage 16 moves at a constant speed in the direction indicated by the arrow C as shown in FIG. Then, the image reading sensor unit 24 that moves together with the sensor carriage 16 reads an image of the medium placed on the medium placement plate 20 and stopped.

  When the image data read by the operation of the image reading unit 13 as described above is transferred to the image forming unit 1, the image forming unit 1 starts the above-described image forming operation.

  As described above, in the present embodiment, the reading position where the stopped image reading sensor unit 24 reads the image of the medium supplied by the medium feeding device 14 is the image reading range on the medium mounting plate 20. Is set in. Therefore, the outer shape of the image reading unit 13 can be reduced.

  Further, since the shutter 33 opens and closes in conjunction with the drive of the drive motor 34, the reflection of light when reading an image with the flatbed scanner 15 can be made uniform even with a simple mechanism.

  Next, a second embodiment of the present invention will be described. In addition, about what has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol. The description of the same operations and effects as those of the first embodiment is also omitted.

  FIG. 10 is a sectional view showing the configuration of the image reading unit according to the second embodiment of the present invention, and FIG. 11 is a perspective view showing the configuration of the drive unit of the image reading unit according to the second embodiment of the present invention. 12 is a perspective view showing the configuration of the medium pressing plate of the image reading unit according to the second embodiment of the present invention. FIG. 13 is a first view showing the configuration of the main part of the image reading unit according to the second embodiment of the present invention. FIG. 14 is a second enlarged sectional view showing the configuration of the main part of the image reading unit according to the second embodiment of the present invention.

  In the present embodiment, the medium feeding device 14 includes a sheet 46 instead of the shutter 33 in the first embodiment as a shutter unit that covers the image reading unit so as to be freely opened and closed. The sheet 46 is fixed to the drive shafts 45 and 47 at both ends in the longitudinal direction, and is wound around the drive shafts 45 and 47. As shown in FIG. 10, the drive shafts 45 and 47 are disposed on both sides in the horizontal direction of the medium pressing member 27 and attached to the base unit 43. Note that gears 49 and 51 are fixed to the drive shafts 45 and 47.

  Further, the sheet 46 extends in the horizontal direction so as to cover the lower surface of the medium pressing member 27 and is disposed so as not to be loose. The sheet 46 is conveyed in the directions indicated by arrows D and E in FIGS. 11, 13 and 14 by rotating the drive shafts 45 and 47. In order to make the conveyance speed of the sheet 46 constant, the drive shafts 45 and 47 and the gears 49 and 51 are formed to have the same shape and the same size, that is, the same diameter and the same number of teeth. Has been.

  The sheet 46 is made of a sheet material having white elasticity showing light reflectivity, and has a colorless and transparent region 46a as a reading window in a part thereof. Then, by conveying the sheet 46 in the directions indicated by arrows D and E in FIGS. 11, 13 and 14, the region 46a is moved along the upper surface of the medium placing plate 20 in the lateral direction in FIG. The seat 46 can be switched between an open state and a closed state.

  As shown in FIG. 10, when the medium is supplied to the flatbed scanner 15 by the medium feeding device 14, the sheet 46 is opened, and the area 46a is in the reading position, that is, the image reading sensor unit in FIG. 24 (position facing the lower surface of the medium pressing member 27 as shown in FIG. 13). Accordingly, the image reading sensor unit 24 stopped together with the sensor carriage 16 can read the image of the medium passing above the image reading sensor unit 24 through the medium placing plate 20 and the region 46a. The reading position, that is, the position where the image reading sensor unit 24 is stopped is within the image reading range of the medium placing plate 20. Further, the medium is conveyed between the area 46a and the medium pressing member 27 along the area 46a. The medium pressing member 27 is urged in the direction of the region 46a by the urging force of the spring 26, and presses the medium against the region 46a.

  Further, when the medium is placed on the medium placement plate 20, the sheet 46 is in a closed state, and as shown in FIG. 14, is moved to the right from the reading position to cover the reading position. It is like that. That is, as shown in FIG. 14, the position facing the medium pressing member 27 in the medium placing plate 20 is covered with a portion other than the region 46 a in the sheet 46.

  In the example shown in the figure, reference numerals 48 and 53 denote shafts for facilitating the conveyance of the sheet 46 and preventing adhesion of scratches and dirt. The shafts 48 and 53 are attached to the base unit 43 so that they can freely rotate about their own axes.

  Further, torque limiters 50 and 52 are attached to the drive shafts 45 and 47 as shown in FIG. The torque limiters 50 and 52 have a function of causing the gears 49 and 51 to idle when a torque exceeding a specified value is applied. The specified value needs to be a value equal to or greater than the torque necessary for conveying the sheet 46, and is, for example, 300 [g * cm].

  The configuration of other points is the same as that of the first embodiment, and a description thereof will be omitted.

  Next, the operation of the image reading unit 13 in the present embodiment will be described. First, an operation when a medium is supplied by the medium feeding device 14 will be described.

  When a medium is placed on the paper feed tray 17, the sensor 42 detects the medium. Subsequently, when the user gives a reading instruction, the drive motor 34 rotates in the direction indicated by the arrow J in FIG. Even when the reading instruction is given, the drive motor 34 does not rotate when no medium is placed on the paper feed tray 17, that is, when the sensor 42 does not detect the medium.

  When the drive motor 34 rotates, the gears 49, 51, 54, 55, 56, 57, 58, 59, and 60 rotate in directions indicated by arrows in FIG. Then, the lock member 38 connected to the drive shaft 35 rotates in the same direction as the gear 54, and comes into contact with the rib 43 a of the base unit 43 and stops. As a result, the lock member 38 holding the hopper 28 is detached from the hopper 28, and the lock of the hopper 28 is released.

  Further, since the drive shafts 45 and 47 rotate in the same direction simultaneously with the rotation of the lock member 38, the sheet 46 is conveyed in the direction indicated by the arrow D in FIGS. Then, when the region 46a reaches the reading position as shown in FIG. 12, the end portion of the sheet 46 on the drive shaft 45 side reaches the portion fixed to the drive shaft 45. That is, all the sheets 46 wound around the drive shaft 45 are fed out and are not fed out further. For this reason, the sheet 46 cannot be conveyed in the direction indicated by the arrow D, and is pulled between the drive shafts 45 and 47. Therefore, since the load is applied to the drive shafts 45 and 47, the gears 49 and 51 are idled by the action of the torque limiters 50 and 52, and the seat 46 is stopped in the pulled state. As a result, the sheet 46 is opened as shown in FIGS. 12 and 13, and the region 46a is exposed.

  On the other hand, when the lock of the hopper 28 is released, the hopper 28 is rotated about the shaft 28 a by the biasing force of the spring 29, and the set medium is brought into close contact with the paper feed roller 22. Then, the medium is fed one by one from the paper feed tray 17 by the paper feed roller 22, and is read by the transport roller 23 fixed to the drive shaft 36, that is, as shown in FIG. As shown, the image reading sensor unit 24 is conveyed to a position above the stopped image reading sensor unit 24. The medium conveyed above the image reading sensor unit 24 is pressed by the medium pressing member 27 and is pressed against the colorless and transparent region 46a of the sheet 46, and the image reading sensor unit 24 that is stopped reads the image. Done.

  When the image reading is completed, the drive motor 34 temporarily rotates in the reverse direction, that is, in the direction opposite to the direction indicated by the arrow J in FIG. As a result, the drive shafts 45 and 47 rotate in the reverse direction, so that the sheet 46 is conveyed in the direction indicated by the arrow E in FIGS. Then, the sheet 46 as shown in FIG. 14 returns to the closed state, and the region 46a is shielded.

  Next, the operation of the image reading unit 13 when a medium is placed on the medium placing plate 20 will be described.

  When the user places a medium on the medium placing plate 20, the sensor 42 does not detect the medium, and therefore the image reading unit 13 has the sheet 46 closed as shown in FIG.

  Subsequently, when the user gives a reading instruction, the sensor carriage 16 moves at a constant speed. Then, the image reading sensor unit 24 that moves together with the sensor carriage 16 reads the image of the medium placed on the medium placement plate 20 and stopped.

  Other operations are the same as those in the first embodiment, and a description thereof will be omitted.

  Thus, in the present embodiment, instead of the shutter 33 in the first embodiment, the sheet 46 is provided, and the sheet 46 is opened and closed. Therefore, the same effects as those of the first embodiment can be obtained, and the medium can be brought closer to the image reading sensor unit 24 by the thickness of the shutter 33, so that the image reading accuracy can be increased. .

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

1 is a diagram illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. 1 is a first cross-sectional view illustrating a configuration of a main part of an image reading unit according to a first embodiment of the present invention. It is a 2nd sectional view showing the composition of the principal part of the image reading unit in a 1st embodiment of the present invention. FIG. 3 is a first perspective view illustrating a configuration of a drive unit of the image reading unit according to the first embodiment of the present invention. It is a 2nd perspective view which shows the structure of the drive part of the image reading unit in the 1st Embodiment of this invention. FIG. 3 is a first perspective view illustrating a configuration of a medium pressing plate of the image reading unit according to the first embodiment of the present invention. It is a 2nd perspective view which shows the structure of the medium press plate of the image reading unit in the 1st Embodiment of this invention. FIG. 3 is a perspective view illustrating a configuration of a shutter of the image reading unit according to the first embodiment of the present invention. It is a time chart which shows operation | movement of the image reading unit in the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the image reading unit in the 2nd Embodiment of this invention. It is a perspective view which shows the structure of the drive part of the image reading unit in the 2nd Embodiment of this invention. It is a perspective view which shows the structure of the medium press plate of the image reading unit in the 2nd Embodiment of this invention. It is a 1st expanded sectional view which shows the structure of the principal part of the image reading unit in the 2nd Embodiment of this invention. It is a 2nd expanded sectional view which shows the structure of the principal part of the image reading unit in the 2nd Embodiment of this invention.

Explanation of symbols

13 Image Reading Unit 14 Medium Feeding Device 16 Sensor Carriage 20 Medium Placement Plate 24 Image Reading Sensor Unit 33 Shutter 34 Drive Motor 46 Sheet 46a Area 101 Window

Claims (7)

(A) an image reading unit for reading an image of a document;
(B) a scanning mechanism that scans the image reading unit in order to read an image of the document placed on the medium placing unit;
(C) a document feeding mechanism that is disposed above the scanning mechanism and that feeds the document to the image reading unit;
(D) An image reading apparatus comprising: a shutter portion that covers the image reading portion so as to be freely opened and closed. The image reading apparatus according to claim 1, wherein the shutter unit opens and closes in conjunction with a drive motor of the document feeding mechanism. The image reading apparatus according to claim 1, wherein the shutter unit is a sheet having a transparent area. The image reading apparatus according to claim 3, wherein the sheet moves in conjunction with a drive motor of the document feeding mechanism. (A) an image reading unit for reading an image of a document;
(B) a scanning mechanism that scans the image reading unit within an image reading range in order to read an image of a document placed on the medium placing unit;
(C) a document feeding mechanism that transports a document and supplies it to the image reading unit;
(D) a shutter unit that covers the image reading unit so as to be freely opened and closed;
(E) When reading an image of a document supplied by the document feeding mechanism, the image reading device is configured to position the image reading unit within the image reading range. When reading an image of a document supplied by the document feeding mechanism, the image reading unit is at a position facing a reading window, the shutter unit opens the window,
The image reading apparatus according to claim 5, wherein when reading an image of a document placed on the medium placing portion, the shutter portion closes the window. An image forming apparatus comprising the image reading apparatus according to claim 1.

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