JP2005277533A - Image scanner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image scanner provided with a means for immediately restoring a pickup roller to a standby position on the upper part, even if the pickup roller moves downward due to the rebound at the time of closing a document pressing plate. <P>SOLUTION: An ADF section A is integrally formed on the document pressing plate 19 which is provided on the top surface of an FBS section F and is vertically openable/closable, and the ADF section A is provided with a vertical rocking mechanism 23 of the pickup roller 3 and a control means 24 for controlling the operation of this mechanism 23. The means 24 performs control so that the pickup roller 3 may be vertically moved when the plate 19 is closed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus in an image forming apparatus such as a copying machine, a facsimile machine, or a multifunction machine combining these functions, and more particularly, an automatic document feeder (ADF) and a flat plate image reading unit (FBS). The image reading apparatus is integrated with a document pressing plate that can be opened and closed.

  In the image forming apparatus as described above, an image reading apparatus including an image reading unit in the ADF and an FBS unit is mounted. As an image reading unit in the ADF, an image reading and scanning apparatus that feeds and separates documents placed on the document placing unit one by one, feeds them to the reading unit of the ADF, and stands by or rests on the reading unit. A system that reads an image of a document sequentially while passing through it has come to be adopted. Further, the FBS unit reads an original image by the image reading / scanning apparatus which places the original document downward on the platen glass and reciprocates along the lower surface of the platen glass. It is designed to be used both for reading FBS documents.

In the case of the image reading apparatus including the image reading unit and the FBS unit in the ADF as described above, the ADF unit may be integrated with a document pressing plate that can be opened / closed vertically provided on the upper surface of the FBS unit. In many cases, Patent Document 1 discloses an example of a paper feeding device in such an image reading device. Further, this Patent Document 1 operates in conjunction with a pick-up roller capable of swinging up and down that acts on the upper surface of a bundle of documents placed on a document placing portion and feeds the document, and swinging of the pickup roller. A shutter (original regulating member) is also disclosed. When the pickup roller is in the upper standby position, this shutter is positioned on the document placement portion and restricts the leading edge of the document bundle placed on the document placement portion so that the pickup roller acts on the document bundle. When the document is fed out, the document is retracted to allow the document to be fed out.
JP 2002-255363 A

  Thus, if the ADF unit is integrated with the document pressing plate as described above, the pickup roller may be lowered due to the reaction when the document pressing plate is opened and closed. FIG. 6 is a conceptual diagram showing the movement of such a pickup roller. FIG. 6 (a) shows a state in which the pickup roller is waiting upward, and FIG. 6 (b) shows a drop due to a reaction as described above. It shows the state. In the figure, the pickup roller 100 is attached to the swinging end portion of a swinging arm 103 that is supported by the drive shaft 102 of the separation roller 101 so as to be swingable up and down. A torque limiter 104 is interposed between the swing arm 103 and the drive shaft 102, and the swing arm 103 swings up and down as the drive shaft 102 rotates due to the action of the torque limiter 104. Further, the rotation of the drive shaft 102 is configured to be transmitted to the pickup roller 100 via the belt 105. Further, a document regulating member 106 that can be displaced between the document leading edge regulating position and the retracted position in conjunction with the vertical movement of the pickup roller 100 is linked to the support shaft of the pickup roller 100. A separation pad 108 elastically biased by a compression spring 107 is elastically contacted with a peripheral body of the separation roller 101.

  As shown in FIG. 6A, when the pickup roller 100 is in the upper standby position, the document restricting member 106 is in the document leading end restricting position, so that the document D has its leading end aligned with the document restricting member 106. Set in state. When the switch of the apparatus is turned on, the pickup roller 100 is lowered from this state, pressed against the upper surface of the document D, and the document regulating member 106 is retracted from the document leading edge regulating position. Thereafter, the pickup roller 100 and the separation roller 101 are driven to rotate so that the document D is fed from the uppermost sheet, and is separated and fed one by one under the action of the separation pad 108. However, when the original pressing plate is closed with force, the pickup roller 100 may be moved downward and maintained as it is, as shown in FIG. 6B. In this state, the pickup roller 100 becomes an obstacle and the document D cannot be set correctly. In addition, since the document restricting member 106 is retracted from the document leading edge restricting position, it is not subject to the restriction, and subsequent feeding / separating feeding of the document is not performed properly, which causes feeding failure and double feeding. .

  The present invention has been made in view of the above circumstances, and even when the pickup roller is moved down due to a reaction or the like when closing the document pressing plate, the pickup roller is quickly returned to the upper standby position. It is an object of the present invention to provide an image reading apparatus that can prevent the occurrence of problems.

In the present invention, a document is fed out by a pick-up roller capable of swinging up and down and pressed against an upper surface of a bundle of documents placed on a document placement unit, and separated one by one by a separation feeding unit, and the document is directed to a reading unit The present invention relates to an image reading apparatus provided with an automatic document feeder for feeding and a flat image reading unit.
According to a first aspect of the present invention, the automatic document feeder is integrally formed with a document pressing plate that is openable and closable, and is provided on an upper surface of the flat plate image reading unit, and an up-and-down swing mechanism of the pickup roller. And a control means for controlling the operation of the mechanism, wherein the control means controls the pickup roller to move upward when the document pressing plate is closed.

  According to a second aspect of the present invention, a document restricting member for restricting the leading end of the document bundle on the document placing portion is provided in the vicinity of the downstream side of the pickup roller. Is located at the document leading edge regulating position on the document placing portion, and when the pickup roller is lowered to a position where it is pressed against the upper surface of the document bundle, it is retracted from the document placing portion. And

  According to a third aspect of the present invention, the separating / feeding means includes a separating roller, and the pickup roller is provided at a swinging end portion of a swinging arm supported so as to swing up and down on a drive shaft of the separating roller. The swing arm is attached and swings up and down in conjunction with the rotation of the drive shaft.

  According to the image reading apparatus of the present invention, when the document pressing plate is closed, the control means controls the pickup roller to move up and down using the vertical swing mechanism. Thus, even if the pickup roller moves downward from the normal upper standby position, the pickup roller quickly returns to the original upper standby position. Accordingly, when the document is set on the document placement portion, the pickup roller does not become an obstacle, and the document is set correctly. And, when a document regulating member that is displaced between the document leading edge regulating position and the retracted position in conjunction with the vertical swing of the pickup roller is provided, the leading edge of the document can always be set to be regulated by this document regulating member. Subsequent feeding / separating feeding is appropriately performed, and poor paper feeding and double feeding are less likely to occur.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a longitudinal sectional view of an essential part showing an example of an image reading apparatus, FIG. 2 is a perspective view of a state in which a drive mechanism in which a pickup roller and a separation roller are unitized is viewed from below, and FIG. 3 is an exploded perspective view thereof. 4 is a control block diagram, and FIG. 5 is an operation flowchart.

  The image reading apparatus 1 shown in the figure is applied to a so-called multi-function machine having a facsimile function, a copying function, and a printer function, and shows an ADF (automatic document feeder) section A and an FBS section (flat plate type). Image reading unit) F. The ADF unit A shown in the figure is configured as a double-sided image reading device for reading a double-sided image and outputting it as a digital signal while conveying a sheet of document D one by one. A document supply tray 2b is detachably attached to the document supply port 2a of the ADF unit A so as to incline downward toward the document supply port 2a. The document supply port 2a and the document supply tray 2b A document placing portion 2 is configured. A pickup roller 3 is provided on the document supply port portion 2a to feed the document bundle D accumulated on the document supply tray 2b from the upper layer portion. The pickup roller 3 is followed to separate the fed documents one by one. Thus, a document separating and feeding means 4 for feeding is provided. The document separating / feeding means 4 includes a separating roller 4a and a retard roller 4b which is elastically contacted with a peripheral body of the separating roller 4a and is urged to rotate in the opposite direction.

  The document fed out by the pickup roller 3 is introduced between the separation roller 4a and the retard roller 4b, and due to the difference in the coefficient of friction with respect to the two papers due to the rotation of the separation roller 4a and the counter-rotation biasing action of the retard roller 4b. Each sheet is separated and fed downstream. Needless to say, the document separating means 4 may be a combination of a separation roller and a separation pad instead of the separation roller 4a and the retard roller 4b.

  Documents separated one by one by the document separating and feeding means 4 are registered rollers (registration means) 6 and large-diameter conveying rollers 7 which are sequentially arranged along a document conveying path 5 formed in a U-turn shape. Is conveyed to the reading point (reading unit) P and then discharged to the discharge tray 9 by the discharge roller 8. Pressure rollers 6a, 7a, 7b and 8a for nipping the document D to be fed are elastically contacted with the rollers 6, 7 and 8. The discharge roller 8 can be rotated forward and backward. When the rear end of the original on which the image on the first surface is read at the reading point P reaches the discharge roller 8, the discharge roller 8 is connected to the rear end of the original by the pressure roller 8a. Is temporarily stopped in the nipped state, and then reversely rotated so that the document D is fed again from the switchback conveyance path 10 through the document conveyance path 5 to the reading point P so that the image on the second surface of the document D is read. It is configured. A switching gate 10a is installed at a branching portion to the switchback conveying path 10, and this switching gate 10a is switched to a position indicated by a broken line when the discharge roller 8 is reversed and the document D is switched back. Control is performed so that the back conveyance path 10 side is opened.

  A slit glass (platen) 11 is disposed at the reading point P, and when the document passes over the slit glass 11, it waits under the slit glass 11 (see the two-dot chain line portion in FIG. 1). Image information on the surface of the document is sequentially read by the scanning device 12 and output as a digital signal as described above. The image reading / scanning device 12 also serves as reading by the FBS unit F. A full-rate carriage (scanning carriage) 14 and a half-rate carriage (scanning carriage) 14 are provided in a box-type reading / scanning casing 13 having a platen glass 18 on the upper surface. A rate carriage (scanning carriage) 15, a condenser lens unit 16, and a CCD 17 are arranged.

  The full rate carriage 14 includes a light source 14b made of a fluorescent lamp or a cold cathode tube and a first mirror 14c mounted on a carriage frame 14a, and is connected to a drive belt 14d and slidable on a guide rail (not shown). And reciprocate left and right within the housing 13 over substantially the entire range. The half-rate carriage 15 includes second and third mirrors 15b and 15c that form an angle of 90 ° on the carriage frame 15a, and is driven at a speed half that of the full-rate carriage drive belt 14d. It is connected to the belt 15d and slidably supported by a guide rail (not shown), and reciprocates left and right within the housing 13 over the range of its substantially left half.

  The drive belts (or toothed belts) 14d and 15d are coaxially mounted on the drive pulleys 14e and 15e having a diameter of 2: 1 and are driven by the same scanning motor (not shown). Is done. Therefore, the full-rate carriage 14 and the half-rate carriage 15 connected to the drive belts 14d and 15d reciprocate so as to follow each other at a speed ratio of 2: 1 by the operation of the motor. The condensing lens unit 16 and the CCD 17 are fixed to the bottom plate 13 a of the housing 13, and when reading the document D 1 placed on the platen glass 18, the full rate stands by on the left side in the housing 13. As the carriage 14 and the half-rate carriage 15 move to the right, the reflected light emitted from the light source 14b to the document D1 is repeatedly reflected by the first to third mirrors 14c, 15b, and 15c, and the condenser lens unit 16 Then, the light is sequentially incident on the CCD 17 to form an image. In the CCD 17, the formed optical information is converted into a digital electric signal and output.

  Further, when reading the ADF document D, as described above, the full-rate carriage 14 moves and stands by at a position directly below the slit glass 11 (the half-rate carriage 15 also stops at a predetermined standby position). In the ADF portion A, the image of the document D continuously conveyed on the slit glass 11 is similarly read. During such scanning, the light reflected by the document D or D1 follows the optical path L and enters the CCD 17, but the moving speed ratio between the full rate carriage 14 and the half rate carriage 15 is 2: 1. The so-called inter-substance distance is always constant, so that the read image quality is kept constant.

  The ADF portion A, the document supply tray 2b, and the discharge tray 9 are integrated to form a document pressing plate (platen cover) 19, and can be opened and closed up and down with the back side of the paper as a hinge portion (not shown). Therefore, when reading the document by the FBS unit F, the document pressing plate 19 is opened and the document is placed on the exposed platen glass 18. A sensor 20 for detecting opening / closing of the document pressing plate 19 is installed on one side of the document pressing plate 19. For convenience of understanding, the sensor 20 is shown on the right side in FIG. 1, but it is located as far as possible from the opening / closing hinge so that even a slight lifting of the pressing plate can be detected, that is, the document. It is desirable to dispose on the front side of the pressing plate 19. Further, a sensor 21 for detecting the presence or absence of a document or the width size of a placed document is installed in the document supply port 2a. A document regulating member 22 that is displaced between the document leading edge regulating position and the retracted position in conjunction with the vertical swing of the pickup roller 3 is provided near the downstream side of the pickup roller 3 in the supply port portion 2a. Yes. Details of this will be described later.

  The image reading and scanning device 12 includes a light source 14b, a plurality of mirrors 14c, 15b and 15c, a lens unit 16 and a CCD 17 mounted on one scanning carriage and reciprocating along the lower surface of the platen glass 18. There may be.

  The separation roller 4a, the registration roller 6, the large-diameter conveyance roller 7 and the discharge roller 8 are driven by a single document conveyance motor (not shown) as a drive source and appropriately via transmission means (same as above) such as a gear or a belt. It is configured to communicate. The pickup roller 3 is configured to be driven and transmitted from the drive system of the separation roller 4a, which will be described in detail below. FIG. 2 is a perspective view of a drive mechanism in which the pickup roller 3 and the separation roller 4a are unitized, as viewed from below, and FIG. 3 is an exploded perspective view thereof.

  The drive shaft 4c of the separation roller 4a rotates with the driving force of the document conveying motor. A pulley 4d that rotates integrally with the drive shaft 4c is fitted to the drive shaft 4c. Further, a separation roller 4a is fitted on the drive shaft 4c so as to be freely rotatable, and a coil spring 4e that conjugates both is fitted on the pulley 4d and the small diameter cylindrical portions 4d1 and 4a1 of the separation roller 4a. . The coil spring 4e functions as a spring clutch. When the drive shaft 4c rotates in the forward direction (in the direction of the arrow X in FIGS. 1 and 2), the rotational force tightens the coil spring 4e. Incorporated. Accordingly, when the drive shaft 4c rotates forward and the pulley 4d rotates integrally, the coil spring 4e is tightened, and the small-diameter cylindrical portions 4d1 and 4a1 are engaged with each other via the coil spring 4e. As a result, the pulley 4d rotates. The separation roller 4a is transmitted to the separation roller 4a, and the separation roller 4a rotates in the normal direction (the direction in which the document is fed), that is, in the X direction.

  The rotation of the pulley 4d is also transmitted to the pickup roller 3. That is, the drive shaft 4c is provided with a swing arm 3a that can swing up and down with the drive shaft 4c as a fulcrum. The support shaft 3b is supported on the front side of the swing arm 3a so as to be rotatable. The pickup roller 3 is fitted so as to be freely rotatable. A pulley 3c is fitted to the support shaft 3b so as to be freely rotatable. A belt 3d is stretched between the pulley 3c and the pulley 4d on the separation roller 4a side, and the pulley 4d on the separation roller 4a side The rotation is transmitted to the pulley 3c on the pickup roller 3 side.

  The rotation of the pulley 3c is transmitted to the pickup roller 3 through a one-way clutch and a differential clutch. That is, a one-way clutch 3e is fitted to the support shaft 3b, and a coil spring 3f is press-fitted to the outer peripheral portion of the one-way clutch 3e and the pulley 3c in a conjugate manner. This coil spring 3f is incorporated in such a relationship that the forward rotation direction of the pulley 3c, that is, the X direction (document feeding direction) is the winding loosening direction. Normally, when the drive is transmitted to the one-way clutch 3e due to the pulley 3c rotating in the X direction, the coil spring 3f is not loosened, and the drive is transmitted by the tightening force. When an abnormal load (for example, a force pulling the document in the reverse direction) is applied to the pickup roller 3, the coil spring 3f is loosened to reduce the impact on the drive transmission system of the pulley 3c and reduce its wear. Can be prevented.

  The one-way clutch 3e functions to be locked to the support shaft 3b when the X direction rotational force shown in FIG. 2 is applied via the coil spring 3f, and to be unlocked when the anti-A direction force is applied. It is. With this lock, the rotational force in the X direction of the pulley 3c is transmitted to the support shaft 3b. As such a one-way clutch 3e, a known one is appropriately selected and adopted as long as it has the above-described function. A differential clutch member 3g is fixed to the support shaft 3b adjacent to the one-way clutch 3e, the differential clutch member 3g includes a clutch pawl 3g1 extending in the thrust direction, and an end surface of the pickup roller 3 is provided in the thrust direction. When the clutch pawls 3g2 are projected and the clutch pawls 3g1 and 3g2 are engaged with each other, mutual rotation transmission is performed.

  The swing arm 3a swings up and down by the swing mechanism 23 in conjunction with forward and reverse rotation of the drive shaft 4c. In other words, the swing mechanism 23 is coupled to one coupling member 23b integrated with the drive shaft 4c via a pin 23a that is inserted through the drive shaft 4c of the separation roller 4a so as to be orthogonal to the axis thereof. A compression spring 23d (torque limiter) is mounted in a compressed state between the other coupling member 23c elastically contacted with the outer surface of the moving arm 3a. Therefore, when the drive shaft 4c rotates forward in the X direction, friction due to the restoring elasticity of the compression spring 23d acts between the coupling members 23b and 23c, so that the swing arm 3a swings in the Y direction. A moving force acts. As a result of the swing arm 3a swinging in the Y direction, the pickup roller 3 comes into contact with the uppermost layer portion of the document D (see FIG. 1) deposited on the document tray 2b.

  If the drive shaft 4c continues to rotate forward even after the pickup roller 3 comes into contact with the uppermost layer portion of the document D, the swing of the pickup roller 3 is prevented by the deposited layer of the document D, but the rotation of the drive shaft 4c is prevented. Continued against the friction force. Accordingly, the rotation of the drive shaft 4c is transmitted to the pickup roller 3 and the separation roller 4a, and the document D on the document tray 2b is fed out from the uppermost layer, separated one by one, and fed toward the conveyance path 5. The With this feeding and feeding, the accumulated layer thickness of the original D on the original tray 2b becomes smaller. However, with respect to the swing arm 3a, the drive shaft 4c always rotates in the X direction while rotating in the X direction. Therefore, the pickup roller 3 is always pressed and urged against the uppermost layer portion of the document D so that the feeding of the document D is not delayed.

  Then, when the feeding and feeding of the document D are completed, the drive shaft 4c is temporarily stopped and then reversely rotated in the anti-X direction, the anti-Y direction force is applied to the swing arm 3a by the friction action of the compression spring 23d. The leading side is lifted by the action, and the pickup roller 3 is held at the standby position above the document tray 2b by the subsequent stop of the drive shaft 4c. In the illustrated example, a felt ring 23e is interposed between the swing arm 3a and the coupling member 23c. The felt ring 23e maintains the integration of the drive shaft 4a and the swing arm 3a due to the friction action of the compression spring 23d, and the pickup roller 3 abuts on the deposited layer of the original to prevent the swing. After that, it functions to relieve the contact friction resistance between the coupling member 23c and the swing arm 3a accompanying the rotation of the drive shaft 4a.

  The document D fed out by the pickup roller 3 and separated one by one by the separation roller 4a reaches the registration roller 6, is registered by the registration roller 6, and is conveyed toward the reading point P. The peripheral speed by the registration roller 6 is set to be slightly higher than the peripheral speed of the pickup roller 3 and the separation roller 4a in order to secure the interval between pages of the document supplied continuously. Therefore, when the leading end reaches the registration roller 6 due to the length of the conveyance path 5, the latter half of the document D is restrained by the separation roller 4a and the pickup roller 3, and therefore the document D is caused by the difference in peripheral speed. A conveyance load (tensile force) is applied to the. The pulling force of the document D acts in the direction of unlocking the coil spring 4e and the one-way clutch 3e as the spring clutch with respect to the separation roller 4a and the pickup roller 3 (separation from the drive shaft 4c and the support shaft 3b). To do. Therefore, the separation roller 4a and the pickup roller 3 are disconnected from the respective drive transmission systems, and are idled to reduce the transport load.

  As described above, while the drive shaft 4c is rotating forward, the pickup roller 3 is always pressed against the uppermost layer portion of the document D, and the drive transmission system from the pulley 4d to the pulley 3c is always operating. Accordingly, when the trailing edge of the preceding document is detached from the pickup roller 3 and the tensile force does not act on the pickup roller 3, the drive transmission from the pulley 3c to the pickup roller 3 is resumed, and the next document is fed out. In this case, when the next original is fed immediately after the action of the tensile force is eliminated, the trailing edge of the preceding original and the leading edge of the next original are simultaneously introduced into the separation roller 4a. The tip is prevented from entering by the separation action of the separation roller 4a and the retard roller 4b.

  The pickup roller 3 is provided with a document regulating member 22 that can be displaced between a document leading edge regulating position and a retracted position in conjunction with the vertical swing of the pickup roller 3. That is, in FIG. 2, an operating bar 22a is extended on the support shaft 3b of the pickup roller 3 (it can be fixed to the swing arm 3a), and the tip of the operating bar 22a is connected to the machine body (ADF). The fixed pin 22b fixed to the machine body of the part A is loosely inserted into the long hole 22d of the rotation link 22c that is rotatably attached. A connecting bar 22e is fixed to the other end of the rotating link 22c in parallel with the operation bar 22a, and a plate-like document regulating member 22 is integrally connected to the connecting bar 22e.

  Accordingly, when the swing arm 3a rotates (downward) in the Y direction as the drive shaft 4c rotates in the X direction, the rotating link 22c moves around the fixed pin 22b in the Z direction under the action of the operating bar 22a. The original regulating member 22 is displaced so as to be flipped up. That is, when the pickup roller 3 is pressed against the original bundle D on the original placement portion 2 and the feeding is started, the original regulating member 22 is displaced to the retracted position. When the feeding of the document D is completed and the reading is completed, the motor rotates reversely and the drive shaft 4c rotates in the anti-X direction. As a result, the swing arm 3a rotates (moves upward) in the anti-Y direction. The restricting member 22 returns to the original document leading edge restricting position. FIG. 1 shows that the document regulating member 22 is in the document leading edge regulating position.

  Since the above-described swing mechanism 23 of the swing arm 3a is subjected to the friction action of the compression spring 23d, a reaction force (inertial force) greater than the friction force is generated when the document pressing plate 19 is closed with force. It may act on the pickup roller 3. Therefore, when the document pressing plate 19 is closed, the pickup roller 3 moves downward and is maintained in this state, which causes troubles in the subsequent setting of the document D. In the present embodiment, when it is detected that the document pressing plate 19 is closed, the document conveying motor is reversely rotated for a predetermined time to move the swing arm 3a upward, and the pickup roller 3 is always moved upward during standby. It is displaced to the standby position. Hereinafter, this control will be described with reference to FIGS.

  FIG. 4 shows a block diagram of a control system in a facsimile apparatus having a copying function or a printer function. The main control unit (control means) 24 is composed of a CPU and controls the operation of all functions as a facsimile machine. The NCU 25 and the modem 26 are connected to an external facsimile machine and function to modulate and demodulate various transmission signals accompanying transmission and reception via this communication line. The image memory 27 mainly stores image data received from an external terminal (facsimile device or personal computer) temporarily. The RAM 28 includes an image information storage unit 28a that temporarily stores image information read by the image reading and scanning device 12, and also includes a storage unit for various data such as a one-touch dial number. The ROM 29 stores various operation programs for the facsimile apparatus.

  The display unit 30 is composed of a liquid crystal panel or the like, and is for visually informing the operator of various information or guidance such as operation procedures and error displays. The operation unit 31 includes various operation means operated by an operator in addition to a start key (not shown), a numeric keypad, and various function keys (including a single-sided / double-sided reading mode setting key). The reading unit 12 and the document feeding unit 32 correspond to the image reading scanning device 12 and the ADF unit A in FIG. The document feeder 32 includes a document transport motor (not shown) as a drive source for transport rollers such as the separation roller 4a.

  The recording unit 33 prints out image data read by the reading unit 12, image data received through the NCU 25, and image data received from an external terminal such as a personal computer. A known recording means such as an ink ribbon method or an ink jet method is employed. Although not shown in FIG. 1, the recording unit 33 is disposed under the image reading apparatus 1. As described above, the document pressing plate opening / closing detection sensor 20 is provided on one side of the document pressing plate 19 and detects opening / closing of the document pressing plate 19.

  FIG. 5 shows an operation flow for opening and closing the document pressing plate 19 and the upward movement of the pickup roller 3. That is, the document pressing plate open / close detection sensor 20 detects that the document pressing plate 19 is open in step S1. Thereafter, in step S2, when the document pressing plate open / close detection sensor 20 detects that the document pressing plate 19 is closed, the main control unit 24 reversely operates the document conveying motor constituting the document feeding means 32. (Step S3). Along with this, the swing arm 3a rotates in the anti-Y direction (see FIG. 2), the pickup roller 3 moves up, and the pickup roller 3 is maintained at the upper standby position by the subsequent stop of the motor (step S4). Is done. The motor is stopped by a time-up of a preset timer (not shown) sufficient for the pickup roller 3 to reach the upper standby position from the start of the reverse rotation operation of the motor.

  As described above, when the document pressing plate 19 is closed, the pickup roller 3 is moved upward and maintained at the upper standby position, so that subsequent document setting is not hindered by the pickup roller 3. Further, when the pickup roller 3 is in the standby position, the document restricting member 22 is always located at the regular document leading edge restricting position, so that the restricting action is accurately performed.

  In addition, as an example of the swing arm 3a, that is, the vertical swing mechanism 23 of the pickup roller 3, the configuration interlocked with the drive shaft 4c of the separation roller 4a has been described, but the solenoid and the input arm disclosed in Patent Document 1 are also described. It may be due to. The document regulating member 22 may also be configured to appear and disappear on the document placement unit 2 in conjunction with the registration roller 6 via a shutter disclosed in Patent Document 1 or a link mechanism as appropriate. Further, although the image reading apparatus for double-sided reading has been described, it is needless to say that it can be applied to an image reading apparatus for single-sided reading, and in addition, a so-called 1-through type double-sided reading system may be used.

It is a longitudinal cross-sectional view of the principal part which shows an example of an image reading apparatus. It is the perspective view of the state which looked up at the drive mechanism which united the pick-up roller and the separation roller from the bottom. It is the same exploded perspective view. It is a control block diagram of the apparatus. FIG. 5 is an operation flowchart of opening and closing of a document pressing plate and an upward movement of a pickup roller. FIG. 4A is a conceptual diagram showing the movement of a pickup roller in a conventional image reading apparatus. FIG. 4A shows a state where the pickup roller is waiting upward, and FIG. 4B shows a state where the pickup roller is lowered due to a reaction or the like.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reading device, 2 Document loading part, 3 Pickup roller
3a swing arm, 4 separation feeding means, 4a separation roller,
19 document pressing plate, 22 document restricting member,
23 Up-and-down swing mechanism of the pickup roller 24 Main control unit (control means)
A ADF section (automatic document feeder), D document (document bundle),
F FBS unit (flat plate type image reading unit), P reading point (reading unit).

Claims (3)

Automatic feeding of a document by a vertically swingable pickup roller pressed against the upper surface of a document stack placed on the document placement unit, and separating the documents one by one by a separation feeding unit and feeding the document toward the reading unit An image reading apparatus comprising a document feeder and a flat image reading unit,
The automatic document feeder is formed integrally with a document pressing plate that is mounted on the upper surface of the flat-plate-type image reading unit and can be opened and closed, and controls the vertical movement of the pickup roller and the operation control of this mechanism. Control means to perform,
The image reading apparatus according to claim 1, wherein the control unit controls the pickup roller to move upward when the document pressing plate is closed.   In the vicinity of the downstream side of the pickup roller, a document restricting member for restricting the leading end of the document bundle on the document placing portion is provided. When the pickup roller is in the upper standby position, the document restricting member is 2. The apparatus according to claim 1, wherein the document is positioned at a document front end regulating position on the placement unit, and is retracted from the document placement unit when the pickup roller is lowered to a position where it is pressed against the upper surface of the document bundle. Image reading apparatus.   The separation feeding unit includes a separation roller, and the pickup roller is attached to a swinging end portion of a swinging arm supported on a drive shaft of the separation roller so as to swing up and down. 3. The image reading apparatus according to claim 1, wherein the swinging is performed in conjunction with the shaft rotation of the drive shaft.

Images