JP4597408B2 - Automatic document feeder and image reading apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic document feeder mounted on an image forming apparatus such as a copying machine or an image reading apparatus.
[0002]
[Prior art]
Conventionally, a sheet-through method in which an image is read while a sheet document is conveyed by a fixed reading unit, and a document (including a book document) is stationary on a contact glass, and the reading unit is moved to perform image reading. In an automatic document feeder (ADF) capable of reading (pressure plate method), the pressure plate that presses the document against the contact glass is composed of one resin white sheet having elasticity and one sponge sheet. ing. Here, due to the mechanical configuration of the ADF, a guide plate (a guide portion for scooping up a sheet document by a sheet-through method) that is opened during maintenance such as document jam processing and roller cleaning is located at the bottom of the ADF, and the guide plate A configuration in which a pressure plate is attached is unavoidable.
[0003]
Related to this type of apparatus are Japanese Patent Laid-Open Nos. 05-188491 and 10-153889. In the technique disclosed in Japanese Patent Application Laid-Open No. 05-188491, the auxiliary friction sheet is made detachable from the pressure plate, and when the existing friction sheet becomes dirty, the existing friction sheet is covered with the auxiliary friction sheet for copying. . In the technique disclosed in Japanese Patent Laid-Open No. 10-153889, one side of the pressure plate (OC mat) is fixed to the bottom surface of the ADF with a double-sided tape or the like, and the other side (pressure plate open side) can be attached and detached. At times, the platen is opened halfway.
[0004]
Further, as shown in FIG. 9, a sponge sheet 90a ′ adhered to the bottom surface of the guide portion 90g ′ for scooping up the document, and a lower cover 90f ′ on the ADF side, while being adhered to the single resin white sheet 90 ′. It is conceivable that a sponge sheet 90b 'adhered to the bottom surface of the sheet is provided, and the guide portion 90g' rotates around the rotation fulcrum 90h 'to open during jam processing. In this case, sponge sheets 90 a ′ and 90 b ′ are attached to the white sheet 90 ′ in order to absorb an impact when the pressure plate is opened and closed, and a guide portion 90 g that scoops up the document by a sheet through method for jam processing. ′ Is rotatable.
[0005]
[Problems to be solved by the invention]
However, in the technique disclosed in Japanese Patent Application Laid-Open No. 05-188491, the presence of the pressure plate interferes with the opening of the guide plate. Therefore, it is necessary to remove the pressure plate itself in order to open the guide plate. is there. Further, in the technique disclosed in Japanese Patent Application Laid-Open No. 10-153889, when the pressure plate is half-opened, the pressure plate sheet may be forcibly bent.
[0006]
Further, in the configuration shown in FIG. 9, since the sponge sheet 90b ′ is fixed to the bottom surface of the lower cover 90f ′ on the ADF side, when the guide portion 90g ′ is opened for jamming, the white sheet 90 ′ is moved downward. The sponge sheets 90a ′ and 90b ′ and the white sheet 90 ′ are bent to form a gap between the operator's hand and foreign matter.
[0007]
An object of the present invention is to provide an automatic document feeder and an image reading apparatus capable of improving such problems and improving operability and safety during jam processing and maintenance.
[0008]
[Means for Solving the Problems]
  The invention according to claim 1 is a fixed reading system in which an original is stopped and an image is read by moving a reading unit.And an automatic document conveying device applied to an image reading apparatus capable of reading any image of a sheet-through method in which the reading unit is fixed and an image is read while conveying the document, and the fixed reading methodThe pressure plate that presses the document to correspond toAnd a housing in which a document transport path for transporting a document in the sheet-through method is formed, and a housing for opening the document transport path to the outside. An outlet unit that is pivotally attached to the housing with the pivoting fulcrum provided as a fulcrum, and the pressure plate is fixed to the lower surface of the outlet unit.A first sheet-like elastic member;A mounting member mounted parallel to the bottom surface of the housing at a position spaced from the outlet unit and movable in a direction perpendicular to the axial direction of the pivot fulcrum; and a lower surface of the mounting memberA fixed second sheet-like elastic member;A white sheet-like elastic member having one end fixed to the lower surface of the first sheet-like elastic member and the other end fixed to the lower surface of the second sheet-like elastic member, and the outlet A rotation fulcrum of the unit is provided above the white sheet-like elastic member, and when the front end of the outlet unit is rotated downward so as to open the document conveyance path, the second sheet is provided. When the elastic member moves together with the mounting member in the separating direction away from the outlet unit, the other end side of the white sheet elastic member moves in the separating direction.There is a special feature.
[0009]
  When the housing is openThat is, when the document transport path is openedThe first sheet-like elastic member is used for jam processing and maintenance.By turning the outlet unitWhen the second sheet-like elastic member is moved in accordance with the opening operation, the second sheet-like elastic member moves in parallel with the bottom surface of the housing, so that the white sheet is formed at the separation portion between the first sheet-like elastic member and the second sheet-like elastic member. The elastic member is not bent or bent.For this reason, even if the pressure plate is attached to the bottom of the ADF, the guide plate at the bottom of the ADF can be smoothly opened and closed without forcibly bending the white sheet-like elastic member of the pressure plate.Therefore, the operability when the housing is opened can be improved, and the operator's hand and foreign matter can be prevented from entering between the ADF bottom and the pressure plate.
[0010]
  The white sheet-like elastic memberBy turning the outlet unitSwing with opening movement,End side of outlet unitButRotate downwardThe white sheet-like elastic member is made of resin and has an appropriate rigidity,Of the mounting member during parallel movement with respect to the bottom of the housingIf the resistance is appropriately small, the white sheet-like elastic member will not bend and the horizontal direction (Bottom of the enclosure(Parallel direction).
[0011]
  The invention described in claim 2In Claim 1, The said case to which the said attachment member is attached is in the said sheet through system.The bottom cover of the stack part that temporarily stores the originals after scanningIsThere is a special feature.
[0013]
  According to a third aspect of the present invention, in the second aspect, the bottom coverBottomIsParallel to the separation directionRail grooveAnd the mounting member isSlide rail that fits into the rail grooveIsThere is a special feature.
[0014]
  TheRide railIsAnd the bottom cover at the bottom of the ADFSecond sheet-like elastic memberMove in directions parallel to each other,WhiteThe bottom of the ADF without forcibly bending the colored sheet-like elastic memberOut ofMouth unitInIt will be able to open smoothly.
[0015]
The invention according to claim 4 is the invention according to claim 2, wherein each of the first sheet-like elastic member and the second sheet-like elastic member includes a resin sheet member and a foamable resin sheet member, The pressure plate is formed by sandwiching the foamable resin sheet member between the resin sheet member and the white sheet-like elastic member.
[0016]
While sandwiching a sponge sheet-like cushion member (included in the first and second sheet-like elastic members) with a resin white sheet-like elastic member and a resin sheet member, while absorbing the impact at the time of opening and closing the pressure plate, The sheet shape of the pressure plate portion can be maintained.
[0017]
  The invention according to claim 5 is the sheet material made of expandable resin and the white sheet-like elastic member constituting the first sheet-like elastic member according to claim 4,The tip side farthest from the pivot pointIt is characterized by being partly bonded.
[0018]
  OutMouth unitToWhen a foam resin sheet member (sponge sheet cushion) is bonded to the entire bottom surface, OutThe white sheet-like elastic member (pressure plate white sheet) may be bent by the opening operation of the mouth unit. Therefore, by adhering only to a part on the upstream end side in the conveyance direction so as to reduce the adhesion area,White sheet-like elastic memberIt will be possible to avoid bending.
[0019]
  The invention according to claim 6, ContractThe automatic document feeder according to any one of claims 1 to 5 is provided.
[0020]
  Like above-mentioned,White sheet-like elastic memberWithout forcibly bending the ADF bottomOutlet unitCan be opened and closed smoothly, improving operability during jam handling and maintenance, andOutlet unitAn image reading apparatus capable of preventing the operator's hand and foreign matter from entering the opening when the is open is realized.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an overall configuration of an image reading apparatus according to an embodiment of the present invention.
The image reading apparatus according to the present embodiment has a reading section I fixed at a predetermined position, and a sheet-through method (automatic conveyance mode) that reads an image while conveying a document 1 to be read at a predetermined speed, and a book original. Or the like can be placed on the contact glass 21b, and a fixed reading method (pressure plate mode) in which an image is read while moving the reading unit I can be executed. A device (hereinafter referred to as ADF) is mounted.
[0022]
On the main body side of the image reading apparatus, a reading unit I is provided that is movable in the horizontal direction below the contact glasses 21a and 21b. The reading unit I includes a light source, a mirror, a lens, a CCD, and the like (not shown), and reads a surface image of a document from below the contact glasses 21a and 21b. The image read in this way is converted into an electrical signal via the CCD and stored in an image memory (not shown). Note that the reading unit I reads the white background plate 32 while moving from the home position (position A) in the vicinity of the reading position 20 to the position A ′ at a predetermined timing (including when the document reading is started), and correction used for shading correction. Get the data.
[0023]
On the other hand, the ADF includes a document setting unit A for setting a document bundle composed of a plurality of documents 1 to be read, a separation feeding unit B for separating and feeding the documents one by one from the set document bundle, A registration unit C that pulls out and conveys the aligned original, and turns the conveyed original so that the original is directed toward the reading side (downward). In the automatic conveyance mode, a first reading conveyance unit E for reading the front surface image of the original document from below the contact glasses 21a and 21b, a second reading conveyance unit F for reading the back side image of the original document after reading the front surface, and reading the front and back sides The paper discharge unit G that discharges the completed document to the outside of the apparatus, the stack unit H that stacks and holds the document after reading, the drive units 101 to 105 that drive these conveyance operations, and a controller that controls a series of operations. Comprising the like over La 100 (shown in FIG. 2).
[0024]
Here, when the lower guide plate (included in the outlet unit 90g) is opened for jamming, the pressure plate white sheet 90 is bonded to the pressure plate white sheet 90 so that the opening operation of the outlet unit 90g is not hindered. The sheet-made sheets 90c and 90d and the slide rail 90e which slides the resin-made sheet 90d in the horizontal direction are provided, and the platen white sheet 90 can be moved in the horizontal direction while being attached to the ADF side. Further, in order to make the upper surface height of the contact glass 21a used in the image reading of the sheet-through method and the upper surface height of the contact glass 21b used in the image reading of the fixed reading method equal to the thickness of the resin sheet 90c, after the reading. The thickness from the document scooping mechanism (including the lower guide plate) to the paper discharge mechanism (lower cover 90f) is set to be thinner than before.
[0025]
The configuration of the control unit of the image reading apparatus according to the present embodiment is as shown in FIG. The controller 100 includes detection signals from the document set sensor 5 and the registration sensor 17, status signals from each motor (for example, a stepping motor) 101 to 105, and an interface unit (such as a serial communication line) with the main body controller 111 ) The control signal (document feed signal, reading start signal, etc.) transmitted through 107 is input.
[0026]
Further, the controller 100 outputs signals (document size signal (width signal, length signal), registration stop signal, discharge completion signal, etc.) based on detection information from the document set sensor 5 and the registration sensor 17 to the main body control unit 111. And driving of the motors 101 to 105 is controlled based on a control signal transmitted from the main body control unit 111. For example, when the document setting sensor 5 detects that the document 1 is set on the document setting table 2, the detection information is transmitted to the main body control unit 111 as a document setting signal by the controller 100 via the interface unit 107.
[0027]
Further, as shown in FIG. 3, the controller 100 supplies power to the contact image sensor 25a disposed on the ADF side. Further, the controller 100 sends timing signals (front DF gate on / off signal, back DF gate on / off signal, etc.) indicating the reading timing to the contact image sensor 61 based on the control signal transmitted from the main body control unit 111. At the same time, the light source for exposure is turned on / off.
[0028]
The contact image sensor 25a includes a light source unit (LED) 208 for exposure at the time of reading a document, a CCD sensor chip 201 that reads an image surface of the document and photoelectrically converts the information into an electrical signal (analog signal), and an analog thereof. An amplifier 202 that amplifies the signal, an A / D converter 203 that converts the amplified analog signal into a digital signal, an image processing unit 204 that generates image information from the digital signal, and a frame for expanding and storing the image information The image information stored in the memory 205 and the frame memory 205 is provided with an output control circuit 206 that sends the image information to the main body control unit 111 via the interface circuit 207, and the image information obtained by performing exposure processing according to the timing signal from the ADF side. Is sent to the main body side.
[0029]
Further, the controller 100 has a RAM (not shown), and this RAM stores the mode (pressure plate mode, automatic transfer mode, single-side mode, double-side mode, etc.) input and set from the operation unit 108 on the main body side, The stored contents are updated every time the setting mode is changed.
[0030]
In this embodiment, when setting the document bundle 1 to be read, the image surface is set on the document table 2 including the movable table 3 with the image surface facing upward. At this time, the document bundle 1 is positioned in the width direction (direction perpendicular to the conveyance direction) by a side guide (not shown). When the document 1 is set, it is detected by the set filler 4 and the document set sensor 5, and this detection information is transmitted from the ADF side to the main body control unit 111 by the interface (for example, serial signal line) 107. Further, a first document length sensor 30 or a second document length sensor 31 (a reflection type sensor or an actuator type sensor that can be detected even with one document) provided on the surface of the document table 2 is used. ) To determine the outline of the length of the document in the conveyance direction. Here, it is necessary to arrange a sensor that can determine at least whether the document size is vertical or horizontal. Further, the movable table 3 is configured to be movable up and down in the directions a and b shown in FIG. 1 by the bottom plate raising motor 105. When the set filler 4 and the set sensor 5 detect that the document 1 is set, The bottom plate raising motor 105 is rotated forward to raise the movable table 3 so that the uppermost surface of the document bundle comes into contact with the pickup roller 7. The pickup roller 7 is operated by the pickup motor 101 in the c and d directions shown in FIG. 1 by the cam mechanism, and the movable table 3 is lifted and is pushed by the upper surface of the document on the movable table 3 and lifts in the c direction. 8, the upper limit can be detected.
[0031]
Further, when a print key (not shown) is pressed by the main body operation unit 108 and a document feed signal is transmitted from the main body control unit 111 to the ADF-side controller 100 via the interface 107, the pickup roller 7 feeds the paper. The roller is rotated by the normal rotation of the motor 102, and several (ideally, one) documents on the document table 2 are picked up. The rotation direction in this case is a direction in which the uppermost document is conveyed to the sheet feeding port. The paper feeding belt 9 is driven in the feeding direction by the normal rotation of the paper feeding motor 102, and the reverse roller 10 is driven to rotate in the reverse direction to the paper feeding by the normal rotation of the paper feeding motor 102. The lower document is separated and only the uppermost document is fed.
[0032]
More specifically, the reverse roller 10 is in contact with the paper feeding belt 9 at a predetermined pressure, and when the paper is in direct contact with the paper feeding belt 9 or in contact with a single document, the reverse roller 10 rotates. It will be rotated counterclockwise. Further, since the reverse roller 10 is set so that the follower force is lower than the torque of a torque limiter (not shown), two or more originals enter between the paper feed belt 9 and the reverse roller 10. When this happens, the paper rotates in the clockwise direction, which is the original driving direction, and pushes back the excess document to prevent double feeding. The document separated into one sheet by the action of the paper feeding belt 9 and the reverse roller 10 is further conveyed by the paper feeding belt 9, the leading edge is detected by the abutting sensor 11, and the pull-out roller 12 is further stopped. I hit it.
[0033]
Thereafter, a predetermined distance is sent from the detection of the abutting sensor 11, and as a result, by stopping the paper feed motor 102 in a state where it is pressed against the pull-out roller 12 with a predetermined amount of bending, The drive of the paper feed belt 9 is stopped. When the leading edge of the original reaches the abutting sensor 11, the pickup motor 101 is rotated to retract the pickup roller from the upper surface of the original, and the original is fed only by the conveying force of the paper feed belt 9. By such an operation, the leading edge of the document enters the nip of the pair of upper and lower rollers of the pull-out roller 12, and the leading edge is aligned (skew correction). The pull-out roller 12 has a function of performing the skew correction, and is a roller for conveying the skew-corrected document to the intermediate roller 14 after separation, and is driven by the reverse rotation of the paper feed motor 102. During the reverse rotation of the paper feed motor 102, the pull-out roller 12 and the intermediate roller 14 are driven, but the pickup roller 7 and the paper feed belt 9 are not driven.
[0034]
A plurality of width size sensors 13 are arranged in the depth direction, and detect the size in the width direction (direction orthogonal to the conveyance direction) of the documents conveyed by the pull-out roller 12. Note that the length of the document in the conveying direction can be detected from the motor pulse during detection of the leading and trailing edges of the document by the butting sensor 11. When the document is conveyed from the registration unit C to the turn unit D by driving the pull-out roller 12 and the intermediate roller 14, the conveyance speed at the registration unit C is set to be higher than the conveyance speed at the reading conveyance unit E. This shortens the processing time for sending the document to the reading unit I. When the leading edge of the document is detected by the reading entrance sensor 15, before the leading edge of the document enters the nip of the upper and lower roller pairs of the reading entrance roller 16, deceleration is started in order to make the document transportation speed the same as the reading transportation speed. At the same time, the reading motor 103 is driven forward to drive the reading inlet roller 16, the reading outlet roller 23, and the CIS outlet roller 27. Thereafter, when the registration sensor 17 detects the leading edge of the document, the controller 100 decelerates over a predetermined conveyance distance, pauses just before the reading position 20, and sends a registration stop signal to the main body control unit 111 via the interface 107. Send.
[0035]
Next, when the controller 100 receives a reading start signal from the main body control unit 111, the controller 100 speeds up and conveys the document until the leading edge of the document that has stopped being registered reaches the reading position. Also, at the timing when the leading edge of the document detected by the pulse count of the reading motor 103 reaches the reading unit I, the gate signal indicating the effective image area in the sub-scanning direction on the first surface is sent to the main body control unit 111 in the first reading conveyance. Sent through part E until the trailing edge of the original comes off.
[0036]
Here, in the case of single-sided document reading, the document that has passed through the reading conveyance unit E is conveyed to the paper discharge unit G through the second reading unit 25. At this time, when the leading edge of the original is detected by the paper discharge sensor 24, the paper discharge motor 104 is driven to rotate forward to rotate the paper discharge roller 28 counterclockwise. Further, the drive pulse of the discharge motor 104 from the detection of the leading edge of the document by the discharge sensor 24 is counted, and the discharge motor driving speed is reduced immediately before the trailing edge of the document comes out of the nip between the upper and lower roller pairs of the discharge roller 28. Thus, control is performed so that the document discharged onto the discharge tray 29 does not jump out.
[0037]
In the case of double-sided document reading, the second reading unit 25 is detected when the leading edge of the document reaches the second reading unit 25 by the pulse count of the reading motor 103 after the leading edge of the document is detected by the paper discharge sensor 24. Then, a gate signal indicating an effective image area in the sub-scanning direction is transmitted from the controller 100 through the reading unit I until the trailing edge of the original is removed. The second reading roller 26 serves as a white reference part for acquiring shading data in the second reading unit 25 at the same time as suppressing the floating of the original in the second reading unit 25.
[0038]
Next, the configuration and operation of the pressure plate portion including the pressure plate white sheet 90, the first cushion 90a, the second cushion 90b, the first resin sheet 90c, the second resin sheet 90d, and the slide rail 90e will be described.
[0039]
  As shown in FIG. 4, the member attaching method in the pressure plate part is by adhesion using a double-sided tape or the like. The pressure plate white sheet 90 is made of resin, and presses the original on the contact glass 21b and is used as a white reference. On the back surface of the pressure plate white sheet 90 (the surface that does not face the contact glass 21b), one side of the two sponge sheet-like cushions 90a and 90b is moderate so that the opening / closing operation of the outlet unit 90g is not hindered. They are bonded with an appropriate bonding area at intervals. Furthermore, the other side of each of the cushions 90a and 90b (the side where the pressure plate white sheet 90 is not bonded) has one side of the resin sheets 90c and 90d divided into two so as not to hinder the opening / closing operation of the outlet unit 90g. In this way, they are bonded with an appropriate bonding area with an appropriate interval. The other side of the resin sheet 90c (the surface to which the cushions 90a and 90b are not bonded) is bonded to the bottom surface of the outlet unit 90g, and the other side of the resin sheet 90d (the cushions 90a and 90b are bonded). The surface that has not been bonded) is bonded to the slide rail 90e. As shown in FIG. 5, the slide rail 90e is provided with a lower cover 90f disposed below the paper discharge tray 29.(Bottom cover)Is slidably attached in a horizontal direction (a direction parallel to the bottom surface of the lower cover 90f). Therefore, the pressure plate portion can slide in the horizontal direction.
[0040]
With such a configuration, from the state where the opening (outlet unit 90g) for jamming at the bottom of the ADF is closed (shown in FIG. 6A), the opening is opened as shown in FIG. 6B. In this case, the pressure plate white sheet 90 is gently bent at the portion where the cushions 90a and 90b are not bonded, and the entire pressure plate moves in a direction parallel to the bottom surface of the ADF. Therefore, the opening for jam processing at the bottom of the ADF can be opened smoothly and sufficiently without removing the pressure plate itself. Further, since the pressure plate white sheet 90 is bent so as to form a curved surface, a crease is formed in the bent portion, and the fold is not reflected in the read image. Further, when the opening is opened, a gap for entering foreign matter does not occur between the pressure plate white sheet 90 and the ADF bottom, so that an accident caused by foreign matter can be prevented.
[0041]
Here, the conditions under which the pressure plate portion including the pressure plate white sheet 90 slides properly when the jam processing opening (exit unit 90g) at the bottom of the ADF opens from the closed state (normal state) will be described.
[0042]
Assuming that the force exerted by the outlet unit 90g on the pressure plate white sheet 90 when the opening is opened from the normal state is an opening force, as shown in FIG. 7B, the rotation fulcrum of the outlet unit 90g is the sheet (pressure plate white sheet 90). The horizontal component Fx of the opening force is not generated at the moment of opening. On the other hand, as shown in FIG. 7A, when the rotation fulcrum of the outlet unit 90g is above the sheet (corresponding to the pressure plate white sheet 90), the horizontal component Fx of the opening force is generated at the moment of opening. Here, when Fs is a force necessary to cause the sheet to bend, and Fa is a maximum static frictional force of a movable mounting portion of the seat (equivalent to a slide mechanism such as a slide rail 90e), The condition for “the sheet slides in the horizontal direction without bending” is Fs> Fx> Fa.
[0043]
Further, when the pressure plate white sheet 90 is adhered to the entire bottom surface of the scooping portion (included in the outlet unit 90g), as shown in FIG. 8, when the outlet unit 90g rotates by a rotation angle of 2θ or more, the bottom surface corresponding to the angle θ The sheet is drawn upward from the original sheet position, and the sheet is bent. Therefore, the pressure plate white sheet 90 is bonded to a part of the bottom surface of the scooping portion, for example, on the upstream side in the transport direction (left side in the drawing) with respect to the rotation fulcrum of the outlet unit 90g.
[0044]
The pressure plate white sheet 90 and the like constitute the white sheet-like elastic member, the sponge sheet 90a and the resin sheet 90c and the like constitute the first sheet-like elastic member, and the sponge sheet 90b and the resin sheet 90d and the like. The second sheet-like elastic member is constituted, the slide rail 90e and the like constitute the attachment member, the outlet unit 90g and the like constitute the opening means, and the resin sheets 90c and 90d and the like constitute the resin sheet member. The sponge sheets 90a, 90b and the like constitute the foamable resin sheet member.
[0045]
【The invention's effect】
  BookAccording to the invention, when the first sheet-like elastic member swings with the housing opening operation, the second sheet-like elastic member moves in parallel with the bottom surface of the housing, so that the white sheet-like elastic member (for example, The opening operation of the housing can be performed without deforming or damaging the pressure plate white sheet made of resin, and the operator's hand or foreign matter can be prevented from entering between the ADF bottom and the pressure plate when the housing is opened..
[0046]
  BookAccording to the invention, the pressure plate is attached to the ADF bottom by using a movable attachment method (a method using a slide mechanism or the like) in which the ADF bottom and the pressure plate are movable only in directions parallel to each other. Even if the ADF is attached, a part of the bottom surface of the ADF can be opened smoothly and sufficiently, and therefore, the operability during the ADF jam processing and maintenance is good. Here, the bending generated in the white sheet-like elastic member (for example, the resin-made pressure plate white sheet) constituting the pressure plate is relatively gentle and does not have a crease, so there is no influence on the read image. Furthermore, the gap generated between the ADF bottom and the pressure plate during ADF jam processing and maintenance is smaller than when the pressure plate is removed or when the pressure plate is slid, thereby preventing the operator's hands and foreign objects from entering.
[0047]
  BookAccording to the invention, the rail groove provided in the bottom cover of the ADF is fitted to the slide rail to which the pressure plate portion is attached, and the guide plate and the pressure plate at the bottom of the ADF move in directions parallel to each other. The guide plate at the bottom of the ADF can be opened and closed smoothly without forcibly bending the elastic member.
[0048]
  BookAccording to the present invention, the first and second sheet-like elastic members (sponge sheet-like cushion members) are laminated between the white pressure plate sheet made of resin and the resin sheet so that the impact at the time of opening and closing the pressure plate with a sponge or the like. And the sheet shape of the pressure plate portion can be held by the resin sheet.
[0049]
  BookAccording to the invention, bending of the pressure plate white sheet can be avoided by bonding only at a part on the upstream end side in the conveyance direction so as to reduce the bonding area between the outlet unit and the sponge sheet-like cushion.
[0050]
  BookAccording to the invention, the image reading apparatus includes the ADF that can smoothly open and close the guide plate at the bottom of the ADF without forcibly bending the pressure plate white sheet as described above. When the guide plate is in the open state, it is possible to prevent an operator's hand or foreign matter from entering the opening.
[0051]
As described above, according to the present invention, it is possible to improve the operability and safety at the time of jam processing and maintenance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an overall configuration of an image reading apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a control unit of the image reading apparatus according to the embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a second reading unit according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a configuration of a pressure plate portion according to an embodiment of the present invention.
5 is a cross-sectional view (sliding mechanism) along AA in FIG.
FIG. 6 is a cross-sectional view showing a bending at the time of horizontal movement of a pressure plate part according to an embodiment of the present invention.
FIG. 7 is a schematic diagram for explaining an opening force of a document scooping portion (exit unit) according to an embodiment of the present invention.
FIG. 8 is a schematic diagram for explaining an adhesion position (size of adhesion area) between a document scooping portion (exit unit) and a pressure plate white sheet according to an embodiment of the present invention.
FIG. 9 is a cross-sectional view showing a configuration (when fixed) of a pressure plate portion in a conventional automatic document feeder.
[Explanation of symbols]
1 Manuscript
2 Original table
20 Reading position
21a, 21b Contact glass
29 Output tray
90 pressure plate white sheet
90a, 90b sponge sheet
90c, 90d resin sheet
90e slide rail
90f lower cover
90g outlet unit
90h fulcrum
I reading section

Claims (6)

An image reading apparatus capable of reading either a stationary reading method in which an original is stationary and an image reading is performed by moving a reading unit and a sheet-through method in which the reading unit is fixed and an image is read while conveying the original. An automatic document feeder that is applied to
A pressure plate for pressing the original so as to correspond to the fixed reading method ;
A casing that holds the pressure plate and has a document transport path formed therein for transporting a document in the sheet-through method,
An exit unit that is pivotally attached to the casing with a pivotal fulcrum provided in the casing so that the document transport path can be opened to the outside; and
The pressure plate is parallel to the first sheet-like elastic member fixed to the lower surface of the outlet unit, the bottom surface of the housing at a position spaced from the outlet unit, and the axial direction of the rotation fulcrum. An attachment member movably attached in an orthogonal direction; a second sheet-like elastic member fixed to the lower surface of the attachment member; one end side fixed to the lower surface of the first sheet-like elastic member; and A white sheet-like elastic member having the other end fixed to the lower surface of the second sheet-like elastic member,
The rotation fulcrum of the outlet unit is provided above the white sheet-like elastic member,
The second sheet-like elastic member moves together with the mounting member in a separating direction away from the exit unit when the leading end side is rotated downward so that the exit unit opens the document conveyance path. Accordingly, the other end side of the white sheet-like elastic member moves in the separating direction . 2. The automatic document feeder according to claim 1, wherein the housing to which the attachment member is attached is a bottom cover of a stack unit that temporarily stores a discharged document after reading in the sheet-through method . A rail groove parallel to the separation direction is formed on the bottom surface of the bottom cover ,
The automatic document feeder according to claim 2, wherein the attachment member is a slide rail that fits into the rail groove.   Each of the first sheet-like elastic member and the second sheet-like elastic member includes a resin sheet member and a foamable resin sheet member, and the resin sheet member and the white sheet elastic member are 3. The automatic document feeder according to claim 2, wherein the pressure plate is formed so as to sandwich the foamable resin sheet member. The foamable resin sheet member constituting the first sheet-like elastic member and the white sheet-like elastic member are bonded to a part of a tip side most distant from the rotation fulcrum. The automatic document feeder according to claim 4. Image reading apparatus is characterized by providing an automatic document feeder according to any one of 請 Motomeko 1-5.

Images