Document feeding device

Abstract

To provide a document feeding device capable of reducing the occurrence of skew of a document when the document is taken into a main body.SOLUTION: The document feeding device includes: a paper feed roller 151 that pulls out documents from a document bundle consisting of multiple documents and transports the documents: separating means that forms a nip with the paper feed roller 151 and separates the documents one by one; a pick arm unit 17 that transports the documents to the nip by pressing the documents against the paper feed roller 151; and a cam shaft 30 that has multiple arm support portions 31. The pick arm unit 17 is capable of moving between a transport position in which it protrudes toward the paper feed roller 151 and the documents and a standby position spaced apart from the paper feed roller 151 and the documents, and the multiple arm support portions 31 support the pick arm unit 17 and hold the pick arm unit 17 in the standby position.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates generally to a document feeder. [Background technology]

[0002] Among document feeders installed in printers, scanners, etc., there are devices that use a liftable pick arm to press a document against a rotating feed roller and take the document into the device (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-101905 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, as shown in Fig. 12, a cam 91 for raising and lowering a pick arm 90 is provided on one side of the pick arm in the document width direction (horizontal direction in Fig. 12(c)). Therefore, the pick arm tilts when it is raised and lowered, and as a result, the pressing force of a pick roller 92 provided on the pick arm against a feed roller 93 differs between the left and right, which may cause the document to skew. [Means for solving the problem]

[0005] In view of the above, a document feeding device according to the present invention is a paper feed roller for extracting and transporting a document from a document stack consisting of a plurality of documents; a separating means for forming a nip with the paper feed roller and separating the document sheets one by one; a pick arm unit that conveys the document to the nip by pressing the document against the paper feed roller; a camshaft having a plurality of arm supports; having the pick arm unit is movable between a transport position where it protrudes toward the feed roller and the document and a standby position where it is spaced apart from the feed roller and the document, The plurality of arm support portions support the pick arm unit and hold the pick arm unit at the standby position. Effect of the Invention

[0006] According to the present invention, it is possible to reduce the occurrence of skewing of the document when the document is taken into the main body. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a diagram showing an example of the configuration of a document feeding device. [Diagram 2] FIG. 2 is a block diagram showing a system configuration of a document feeding device. [Diagram 3] 4 is a flowchart showing a method for performing image reading of a document. [Figure 4] FIG. [Diagram 5] An exploded view of the intake and surrounding area. [Figure 6] FIG. 1 is a schematic side view showing the intake port and the internal structure of the surrounding area (initial state of the device). [Figure 7] FIG. 4 is a side view showing the internal structure of the intake port and its surrounding area. [Figure 8] FIG. 4 is a side view showing the internal structure of the intake port and its surrounding area. [Figure 9] FIG. 4 is a side view showing the internal structure of the intake port and its surrounding area. [Figure 10] FIG. 1 is a schematic side view showing the internal structure of the input port and its surrounding area (after the input of document Sh has been completed). [Figure 11] FIG. 11 is a schematic diagram showing variations in roller width at the intake port. [Figure 12] FIG. 1 is a schematic diagram showing a configuration of a prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] <Overall mechanical configuration> Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features among the multiple features described in the embodiments may be arbitrarily combined.

[0009] <Embodiment> 1 shows an example of the configuration of an original feeding device 1 according to this embodiment. The original feeding device 1 takes in an original Sh to be scanned into the device body (inside a housing 10) and reads the image of the scanned original Sh. The original Sh after image scanning is discharged from a discharge port 11 onto a discharge tray 12. When there are two or more originals Sh, they are stacked on the discharge tray 12.

[0010] Here, the document Sh is a sheet-like member (typically, paper, etc.), and images are formed on one side and the other side of the document Sh. The concept of an image includes visible objects such as characters, symbols, figures, photographs, etc., as well as the surroundings or spaces between them.

[0011] In this embodiment, the document feeder 1 has a scanner function, but in other embodiments, the document feeder 1 may additionally or alternatively have other functions. In this respect, the document feeder 1 may be expressed as a document capture device, a document feeder, a feeder, a paper feeder, etc.

[0012] In addition to the discharge tray 12, the document feeder 1 includes a loading tray 13, an intake port 14, a transport mechanism 15, a reading unit 16, a pick arm unit 17, drive sources 18a and 18b, and drive transmission units 19a and 19b.

[0013] The loading tray 13 can hold one or more originals Sh. The loading tray 13 may be referred to as a loading section, but when the originals Sh are paper, it is referred to as a paper feed tray, paper feed section, etc. The loading tray 13 is extended and inclined so that one end on the device body side is downward and the other end is upward. The originals Sh loaded on the loading tray 13 move by their own weight to a position where they come into contact with the paper feed roller 151.

[0014] The intake port 14 is an opening for taking in the document Sh from the loading tray 13 into the device body, and is formed of one or more members in a frame shape.

[0015] The transport mechanism 15 is configured to form a transport path T for the original Sh from the stack tray 13 to the discharge tray 12 in Fig. 1, and in this embodiment includes a paper feed roller 151, a separation roller (separation means) 153, a roller pair (transport rollers) 159a, and a roller pair (discharge rollers) 159b. In Fig. 1, the transport path T for the original Sh is indicated by a dashed line, and the transport direction is indicated as a D0 direction.

[0016] Hereinafter, in this specification, when indicating a relative positional relationship in the conveying direction (D0 direction), the side closer to the loading tray 13 is referred to as the upstream or upstream side, and the side closer to the discharge tray 12 is referred to as the downstream or downstream side.

[0017] The paper feed roller 151 is a drive roller provided near the intake port 14, and receives drive from the drive source 18a via the drive transmission unit 19a to rotate in the D1 direction. The paper feed roller 151 has a built-in one-way clutch, and rotates with the original Sh when the original Sh moves at a speed faster than the peripheral speed of the paper feed roller 151 due to a roller pair (conveyor roller) 159a or the like. A known electric motor may be used for the drive source 18a and the drive source 18b described later.

[0018] The separation roller 153, which is a separating means, is rotatably held in the separation unit 152 in FIG. 5(b) described later, and nips with the feed roller 151 to hold the document Sh taken in through the intake port 14. The separation roller 153 has a built-in torque limiter, and rotates in the D2 direction when driven by the drive source 18a. When a torque equal to or greater than a reference value is applied from the feed roller 151 or the document Sh, the torque limiter runs idle and the document Sh rotates in the D2' direction. As a result, when two or more sheets of document Sh are taken in through the intake port 14, the document Sh on the separation roller 153 side is returned from the intake port 14 onto the stacking tray 13. Or it remains at the intake port 14 and is not transported downstream of the nip (in the D0 direction).

[0019] Here, the separation roller 153 is made of a soft material including sponge, etc. Therefore, when the separation roller 153 is pressed against the document stack Sh, the surface of the separation roller 153 is crushed, and the contact area between the separation roller 153 and the document stack Sh increases. This makes it difficult for the document stack Sh and the separation roller 153 to slip, so that the document stack Sh can be reliably separated one by one.

[0020] With the above-mentioned configuration, the originals Sh are taken into the main body of the apparatus one by one.

[0021] The roller pair 159a is a drive roller and a driven roller arranged between the paper feed roller 151 and the reading unit 16, and holds the document Sh and transports it to the reading unit 16. The roller pair 159b is a drive roller and a driven roller arranged between the reading unit 16 and the discharge port 11, and holds the document Sh and transports it to the discharge port 11. In this embodiment, the drive rollers of the roller pairs 159a and 159b are rotated by being driven by the drive source 18b via the drive transmission unit 19b.

[0022] The reading unit 16 is disposed between the pair of rollers 159a and 159b. In this embodiment, a pair of reading units 16 is installed, one reading unit 16 reading an image on one side of the document Sh, and the other reading unit 16 reading an image on the other side of the document Sh. A known image contact sensor may be used for the reading unit 16, and for example, an imaging device constituted by a CCD / CMOS image sensor may be used.

[0023] <Overall electrical configuration> 2 is a block diagram showing a system configuration of the document feeding device 1. The document feeding device 1 includes a document stacking sensor unit 21a, a double feed detection sensor unit 21b, a first document detection sensor unit 21c, a second document detection sensor unit 21d, an operation input unit 22, and a control unit .

[0024] The document loading sensor unit 21a to the second document detection sensor unit 21d are installed on the transport path T of the document Sh. In Fig. 2, the document loading sensor unit 21a to the second document detection sensor unit 21d are shown as a sensor group 21. The document loading sensor unit 21a is composed of a lever and a sensor arranged upstream of the paper feed roller 151 (see Fig. 4). The lever rotates when the document Sh comes into contact with it, and the sensor detects the movement of the lever and outputs a predetermined detection signal.

[0025] The multi-feed detection sensor unit 21b shown in Fig. 1 is installed downstream of the separation roller 153 inside the housing 10, and detects when separation by the separation roller 153 is not performed properly. When an overlap of documents Sh is detected (when so-called multi-feeding has occurred), a predetermined detection signal is output. In this embodiment, a sensor equipped with an ultrasonic transmission element and a reception element is used to detect multi-feeding by utilizing the attenuation of ultrasonic waves by the documents Sh.

[0026] The first document detection sensor unit 21c is installed upstream of the roller pair 159a and downstream of the double feed detection sensor unit 21b inside the housing 10. It detects that the leading edge of the document Sh has reached the feed roller 151 and outputs a predetermined detection signal. In this embodiment, an optical sensor is used to detect the arrival of the document Sh by the light being blocked by the document Sh.

[0027] The second document detection sensor unit 21d is installed downstream of the roller pair 159a and upstream of the reading unit 16 inside the housing 10. It detects when the leading edge of the document Sh reaches the roller pair 159a and when the trailing edge of the document Sh passes through the roller pair 159a, and outputs a predetermined detection signal. In this embodiment, an optical sensor is used to detect the arrival of the document Sh by the light being blocked by the document Sh.

[0028] The document stacking sensor unit 21a to the second document detection sensor unit 21d may be formed of any known sensor, including a lever-type sensor, an optical sensor, an ultrasonic sensor, or the like, and may be formed of a transmitting sensor and a receiving sensor.

[0029] The operation input unit 22 is an operation panel through which the user inputs instructions to read an image, and may be installed in any part of the housing 10 or the exterior. The operation input unit 22 may also have a function as a display unit, and in this embodiment, a touch panel display is used as the operation input unit 22 as a typical example.

[0030] The control unit 23 includes a CPU (Central Processing Unit) 231, a memory 232, and a communication interface 233. The CPU 231 reads a predetermined program from another memory (non-volatile memory such as ROM) not shown, develops it on the memory 232 (volatile memory such as RAM), and executes each step (see FIG. 3) described later to realize image reading. The CPU 231 can also receive input signals from the operation input unit 22 and detection signals from the document loading sensor unit 21a and the like via the communication interface 233, and can also receive other input signals from external devices not shown.

[0031] In another embodiment, the control unit 23 may be configured with a semiconductor device such as an ASIC (Application Specific Integrated Circuit), that is, the functions of the control unit 23 may be realized by either hardware or software. Also, the control unit 23 may be expressed as a drive control unit, an image reading control unit, a document input control unit, etc. according to its function, or may be provided separately according to each function.

[0032] With this configuration, the control unit 23 performs drive control for each of the above-mentioned elements so as to realize image reading of the original Sh (and the associated intake and discharge of the original Sh) based on the input signal of the operation input unit 22, the detection signal of the original loading sensor unit 21a, etc.

[0033] <Overall software configuration> 3 is a flowchart showing a method for reading an image of an original Sh. This flowchart is mainly executed by the control unit 23.

[0034] In step S1010 (hereinafter simply referred to as "S1010." The same applies to other steps described below), it is determined whether or not there is an instruction to start image reading. If there is an instruction to start image reading, the process proceeds to S1020, and if not, the process returns to S1010.

[0035] In S1020, the presence or absence of the document Sh on the stacking tray 13 is determined based on the detection signal of the document stacking sensor unit 21a. If the document Sh is present on the stacking tray 13, the process proceeds to S1040, and if not, the process proceeds to S1030. Note that if the document Sh is not present, the process may be configured to repeat the determination in S1020 until a predetermined time has elapsed, and to proceed to S1030 after the predetermined time has elapsed.

[0036] In S1030, a notification is output to indicate that no document Sh exists on the stack tray 13, and then this flowchart ends. This notification may be performed by the touch panel display that is the operation input unit 22.

[0037] After S1040, the process starts to take in the original Sh, assuming that the original Sh is present on the stacking tray 13. In S1040, the drive source 18b for driving the roller pair 159a and the like starts to be driven.

[0038] In S1050, the driving source 18a is driven to start driving the sheet feed roller 151. As a result, the document Sh on the stacking tray 13 is taken in through the open intake port 14.

[0039] In S1060, based on a detection signal indicating that the leading edge of the document Sh has reached the document, which is output from the second document detection sensor section 21d, the reading unit 16 starts reading an image of the document Sh while the document Sh is being conveyed. At this time, the first document detection sensor section 21c simultaneously performs jam detection such as whether the document Sh has reached the second document detection sensor section 21d or the like within a predetermined time after the start of driving the paper feed roller 151.

[0040] In S1070, similarly to S1060, the driving of the drive source 18a is stopped based on a detection signal indicating that the leading edge of the original Sh has arrived, output from the second original detection sensor unit 21d, and the driving of the paper feed roller 151 is interrupted or temporarily stopped. That is, when the downstream end (leading edge) of the original Sh reaches the second original detection sensor unit 21d, it means that a single original Sh has been properly taken in, and therefore the start of taking in the next original Sh is suppressed until the image reading and discharge of the original Sh are completed. Note that, although S1060 and S1070 are shown to be executed sequentially in FIG. 3, they may actually be executed in order or simultaneously.

[0041] In S1080, image reading is stopped based on a detection signal indicating that the upstream end (rear end) of the document Sh has passed the second document detection sensor unit 21d, and the presence or absence of the document Sh on the stacking tray 13 is determined based on the detection signal of the document stacking sensor unit 21a. If the document Sh is present on the stacking tray 13, the process returns to S1050, and if not, the process proceeds to S1090. That is, if the document Sh remains on the stacking tray 13, S1050 to S1080 are repeated, and if the document Sh does not remain on the stacking tray 13, the process proceeds to S1090.

[0042] In S1090, it is determined that no originals Sh remain on the stacking tray 13, so the drive source 18b is driven in the direction opposite to the feeding direction of the originals Sh to return the device to the initial state described later, and image reading is completed.

[0043] <Mechanical components> The following describes the driving manner of the pick arm unit 17 and its peripheral configuration that takes in or inhibits the taking in of the document Sh in the document feeding device 1 of this embodiment.

[0044] FIG. 4 is a perspective view of components constituting the intake port 14 shown in FIG. 1, and FIG. 5 is a perspective view showing the components constituting the intake port 14 disassembled. FIGS. 6 to 10 are schematic side views showing the internal structure of the intake port 14 and its surroundings. Note that FIGS. 6(b), 7(b), 8(b), 9(b), and 10(b) are enlarged schematic views of the vicinity of the intake port 14 when viewed from the same direction as FIG. 1, and FIGS. 6(a), 7(a), 8(a), 9(a), and 10(a) are enlarged schematic views of the vicinity of the intake port 14 when viewed from the opposite direction to FIG. 1. FIG. 6 shows the state of the device before the intake of the original Sh starts (standby state), and FIG. 10 shows the state when the intake of all the originals Sh has been completed, and FIGS. 7 to 9 show the states in between in chronological order.

[0045] <Mechanical components - upper side - document stopper> 5(a) shows the cam shaft 30, FIG. 5(b) shows the separation unit 152, and FIG. 5(c) shows the pick arm unit 17. FIG.

[0046] 5(a) causes the arm portion 171 to rotate. The cam shaft 30 is installed in the housing 10 so as to be rotatable about a rotation axis A5, and is biased in the direction D4 by a cam shaft spring (biasing member) 20e. The cam shaft 30 has arm support portions 31 at both ends in the axial direction (width direction of the document Sh) that rotate integrally with the rotation axis A5.

[0047] 5(b) includes a separation roller 153 and a separation holder 154. The separation holder 154 rotatably holds the separation roller 153. Here, the separation unit 152 is fixed to the housing 10 so as to be rotatable about a hole A8 that engages with the shaft A1 as a rotation axis, and is pressed toward the paper feed roller 151 by a separation spring (biasing member) 20a. This allows the document Sh to be sandwiched in the nip between the separation roller 153 and the paper feed roller 151.

[0048] 5(c) has an arm portion 171, which is rotatably installed in the housing 10 around a hole portion A2 that engages with a rotation axis A1 of the separation unit 152. The arm portion 171 has a shape that avoids the range of motion of the separation unit 152, thereby preventing interference without increasing the height of the device.

[0049] Two or more pick rollers 172 (pressing parts) are provided symmetrically in the left-right direction (original width direction) and rotatably supported on the arm part 171. In the case of two pick rollers as in this embodiment, they are provided symmetrically with respect to the center in the left-right direction.

[0050] The arm portion 171 has an engagement portion 176 having a hole portion A2 that engages with the pivot shaft A1 on both left and right ends, and is biased in the direction D6 by a pick spring 20b (biasing member) provided on the engagement portion 176, so that there is no difference between the left and right sides in the force with which the pick roller 172 presses against the paper feed roller 151.

[0051] 6A, the arm portion 171 rotates between a standby position P1 where the pick roller 172 is separated from the document Sh, and a transport position P2 where the pick roller 172 presses against the feed roller 151, as shown in FIG. 10A. When the arm portion 171 is at the standby position P1, the pick roller 172 retreats to a position where it does not contact the document stack Sh placed on the placement surface f1 (see the perspective view of FIG. 4), so that the document Sh is not caught by the pick roller 172 when the document Sh is set. On the other hand, between the standby position P1 and the transport position P2 shown in FIG. 9A, the pick roller 172 contacts the document stack Sh placed on the placement surface f1 by the pick spring 20b, and presses the document Sh against the feed roller 151. Also, at the transport position P2 shown in FIG. 10A, the pick roller 172 presses against the feed roller 151 by the pick spring 20b.

[0052] In this embodiment, the pick roller 172 is a driven roller, but it may be any roller that is driven or slides with the movement of the document Sh.

[0053] As shown in FIG. 5, a document stopper 173 is supported on the arm portion 171 so as to be rotatable about a shaft portion A3 as a rotation axis, and is biased in the direction D3 by a stopper spring (biasing member) 20c.

[0054] When arm portion 171 is in standby position P1 as shown in FIG. 6, locking portion 1731 (see the perspective view of FIG. 5) provided on document stopper 173 locks with housing holding portion 174 of housing 10, and document stopper 173 is held in an upright position.

[0055] On the other hand, when the arm portion 171 is between the standby position P1 and the transport position P2 as in Fig. 8 and Fig. 9, or when it is at the transport position P2 as in Fig. 10, the locking portion 1731 is separated from the housing holding portion 174. Therefore, the document stopper 173 rotates in the D3 direction due to the pressing force of the stopper spring 20c, and changes from the upright position to a tilted position, allowing the document Sh to be taken in.

[0056] When the locking portion 1731 and the housing holding portion 174 are separated from each other, the document stopper 173 abuts and is locked with the locking portion 156 of the separation holder 154. In other words, the document stopper 173 tilts more as the arm portion 171 approaches the transport position P2, and stands upright more as the arm portion 171 approaches the standby position P1.

[0057] 8 to 10 is between the standby position P1 and the transport position P2 or is at the transport position P2, the document stopper 173 functions as a transport surface for the document Sh. The locking portion 156 is formed in an arc shape coaxial with the rotation axis of the separation roller 153. As a result, while the document stopper 173 functions as a transport surface, the amount of protrusion of the separation roller 153 from the document stopper 173 can be kept constant, and a stable paper feeding state can be maintained.

[0058] <Mechanical components - upper side - cam shaft, arm section> The mechanism for raising and lowering the arm portion 171 will now be described.

[0059] 6(a), 7(a), 8(a), 9(a) and 10(a), the arm support portion 31 is indicated by a dashed line and is provided so as to protrude towards the separation roller 153. The axial direction will hereinafter be referred to as the left-right direction.

[0060] The cam shaft 30 rotates between a standby position P3 shown in FIG. 6(a) and a transport position P4 shown in FIG. 10(a). When the cam shaft 30 is at the transport position P4, the arm portion 171 is separated from the arm support portion 31, and the pick roller 172 rotates in the direction D6 by the biasing force of the pick spring 20b until it contacts the document Sh or the feed roller 151. When the cam shaft 30 rotates in the direction D4', the arm support portion 31 engages with the arm holding portion 175 of the arm portion 171, causing the arm portion 171 to rotate in the direction D6' (see FIG. 8(a) and FIG. 9(a)). When the cam shaft 30 rotates to the standby position P3, the arm portion 171 is located at the standby position P1 as shown in FIG. 6, and the pick roller 172 is separated from the feed roller 151 and the document Sh.

[0061] 6(b), 7(b), 8(b), 9(b), and 10(b), the rotation axis A5 of the cam shaft 30 is provided at a position (upper side) farther from the transport path T of the document Sh than the movable ranges of the separation unit 152 and the arm portion 171. On the other hand, the arm support portion 31 of the cam shaft 30 is disposed closer to the transport path T (lower side) than the arm holding portion 175 in order to hold the arm holding portion 175 of the arm portion 171 away from the transport path T when the arm portion 171 is in the standby position P1 as shown in FIG.

[0062] As shown in Fig. 5, the arm support part 31 of the camshaft 30 and the rotation axis A5 are connected by a lever shape 311, but the lever shape 311 is provided on the outside of the arm holding part 175 in the left-right direction. Therefore, when the camshaft 30 and the arm part 171 rotate, the lever shape 311 does not contact or interfere with the arm part 171. With this configuration, only the rotation axis A5 of the camshaft 30 needs to be disposed above the arm part 171 and the separation unit 152, and the movable ranges of the arm part 171, the separation unit 152, and the camshaft 30 are all contained below the rotation axis A5 (on the conveying path T side). Therefore, the height of the device body can be reduced.

[0063] In this embodiment, the cam shaft 30 rotates by being driven by the driving source 18b shown in Fig. 1. The driving source 18b rotates forward when the document Sh is transported, and when the transport of the document Sh is completed, rotates in the reverse direction by a predetermined amount to return the device to the initial state (Fig. 6) and then stops rotating.

[0064] A one-way clutch is disposed in the drive transmission unit 19b that transmits the drive from the drive source 18b to the camshaft 30, and when the drive source 18b is rotated in the reverse direction, the drive is transmitted to the camshaft 30, and when the drive source 18b is rotated in the forward direction, the drive is cut off. As a result, when the drive source 18b is rotated in the reverse direction, the camshaft 30 receives the drive of the drive source 18b and rotates in the D4' direction. By stopping the rotation when the camshaft 30 reaches the standby position P3, the arm portion 171 can be maintained in the standby position P1.

[0065] On the other hand, when the driving source 18b is rotated forward to start transporting the document Sh, the driving force to the cam shaft 30 is cut off, so that the cam shaft 30 rotates in the direction D4 by the biasing force of the cam shaft spring 20e until it reaches the transport position P4 where the abutment 312 abuts against a rotation stopper (not shown). As a result, the arm portion 171 is released from the lock with the arm support portion 31 of the cam shaft 30, and the pick roller 172 rotates by the biasing force of the pick spring 20b until it comes into contact with the document Sh or until it is positioned at the transport position P2.

[0066] In this embodiment, a stepping motor is used for the drive source 18b that drives the camshaft 30, and the amount of rotation can be specified in detail. Therefore, when moving the camshaft 30 to the standby position P3, it is sufficient to reverse the drive source 18b by a specified number of pulses from the state in which the camshaft 30 is at the transfer position P4, and there is no need to use a detection sensor that detects that the camshaft 30 has reached the standby position P3.

[0067] In this embodiment, two paper feed rollers 151 are provided symmetrically about the center in the left-right direction, and two pick rollers 172 for pressing the document Sh against each paper feed roller 151 are also provided symmetrically in the left-right direction.

[0068] When the document Sh is taken into the device body, if the timing at which the left and right pick rollers 172 press the rotating paper feed roller 151 differs between the left and right, the part of the leading edge of the document Sh that is pressed against the paper feed roller 151 by the pick roller 172 first is taken into the device first, and the document Sh is transported at an angle (skewed). Also, if there is a difference in the pressing force of the left and right pick rollers 172, there will be a difference between the left and right in the friction force between the paper feed roller 151 and the paper, and there will be a difference in the timing at which the leading edge of the document Sh is taken into the device in the left and right directions, and the document Sh may be transported at an angle.

[0069] Therefore, it is important that the left and right pick rollers 172 move up and down evenly and are pressed against the paper feed roller 151 with an even pressure.

[0070] According to this embodiment, the arm support portion 31 of the cam shaft 30 supports both arm holding portions 175 at both ends of the arm portion 171 in the left-right direction, so that even if the strength of the arm portion 171 is insufficient, the arm portion 171 can be lowered without tilting to the left or right, and the left and right pick rollers 172 can touch the document Sh at the same time. In addition, since the pick spring 20b is arranged in the engagement portion 176, the force with which the left and right pick rollers 172 press the document Sh against the paper feed roller 151 is uniform, so that the document Sh can be prevented from being skewed when it is taken into the device body.

[0071] In addition, the arm portion 171 is not deformed by being held at an angle in the standby position P1, and a difference in the pressing force of the pick roller 172 between the left and right sides does not occur.

[0072] In this embodiment, the rotation axis A5 of the cam shaft 30 is located at a position that does not overlap with the movable range of the separation unit 152 and the arm portion 171. Therefore, the rotation axis A5 can pass through from left to right, and the left and right arm support portions 31 can be provided as a single component. With this configuration, the arm portion 171 can be reliably moved left and right simultaneously without being affected by backlash, and the pick roller 172 can press the document Sh against the paper feed roller 151 left and right simultaneously.

[0073] In addition, in this embodiment, since the arm support parts 31 at both ends in the axial direction are integrally provided, it is possible to implement an inexpensive configuration without increasing the number of parts. Furthermore, in this embodiment, since only the rotation axis A5 of the cam shaft 30 needs to be disposed above the arm part 171 and the separation unit 152, the height of the device body can be reduced.

[0074] In addition, as an embodiment different from this embodiment, three or more arm holders for raising and lowering the arm may be provided. For example, if the left and right arm holders are provided asymmetrically in the left-right direction, there is a possibility that the left and right arms will bend differently. Also, if there are three or more pick rollers that press the document against the paper feed roller, when the arm bends, the pick rollers closer to the center may press the paper feed roller earlier (or later). In such a case, by adding an arm holder to the center in the left-right direction (the center of the document width) to support the arm, it is possible to prevent the arm from bending and to make all the pick rollers contact the paper feed roller at the same time.

[0075] <Mechanical components - upper side - camshaft, separation unit> As described above, the separation roller 153 is rotatably held by the separation unit 152, and the separation unit 152 is held by the housing so as to be rotatable about the shaft A1. In this embodiment, in order to prevent the separation roller 153 from being pressed against the paper feed roller 151 for a long period of time and being deformed, a mechanism is provided to separate the separation roller 153 from the paper feed roller 151 in the initial state in which the document Sh is not being transported.

[0076] The mechanism for separating the separation roller 153 from the feed roller 151 using the cam shaft 30 that moves the arm portion 171 up and down will be described below.

[0077] As shown in Fig. 5, the cam shaft 30 has a separation holder support part 34 that rotates integrally with the rotation shaft A5. In Figs. 6(b), 7(b), 8(b), 9(b), and 10(b), the separation holder support part 34 is shown by a dashed line and is provided so as to protrude toward the separation roller 153 side (the back side of the page).

[0078] 10(b), when the cam shaft 30 is at the transport position P4, the separation unit 152 and the separation holder support portion 34 are separated, and the separation unit 152 rotates by the biasing force of the separation spring 20a until the separation roller 153 comes into contact with the document Sh or the paper feed roller 151. When the cam shaft 30 rotates in the D4' direction, the separation holder support portion 34 engages with the separation holder holding portion 155, rotating the separation unit 152 in a direction separating it from the paper feed roller 151. When the cam shaft 30 rotates to the standby position P3 as shown in FIG. 6, the separation roller 153 separates from the paper feed roller 151.

[0079] As described above, the rotation axis A5 of the cam shaft 30 is provided at a position (upper side) farther from the transport path T of the document Sh than the movable range of the separation unit 152 and the arm portion 171. On the other hand, the separation holder support portion 34 of the cam shaft 30 is disposed closer to the transport path T (lower side) than the separation holder holding portion 155 in order to hold the separation holder holding portion 155 away from the transport path T in a state in which the separation roller 153 shown in FIG. 6 is separated from the feed roller 151.

[0080] 5, the separation holder support portion 34 of the cam shaft 30 and the rotation axis A5 are connected by a lever shape 341, but the lever shape 341 is provided on the outer side in the left-right direction than the separation holder holding portion 155. Therefore, when the cam shaft 30 and the separation unit 152 each rotate, the lever shape 341 does not contact or interfere with the separation unit 152.

[0081] When the driving source 18b is rotated in the reverse direction, the cam shaft 30 is driven by the driving source 18b and rotates in the direction D4'. When the cam shaft 30 reaches the standby position P3, the rotation is stopped, so that the separation unit 152 can be kept separated from the sheet feed roller 151.

[0082] On the other hand, when the document Sh starts to be transported, the drive source 18b is rotated forward, so that the drive to the cam shaft 30 is cut off, and the cam shaft 30 rotates in the direction D4 by the biasing force of the cam shaft spring 20e until it reaches the transport position P4 where the abutment 312 abuts against a rotation stopper (not shown). As a result, the separation unit 152 is released from the separation holder support portion 34 of the cam shaft 30, and the separation roller 153 rotates by the biasing force of the separation spring 20a until it comes into contact with the document Sh or the paper feed roller 151.

[0083] In this embodiment, the arm portion 171 is integrally provided on the cam shaft 30 that raises and lowers the arm portion 171, and on the separation holder support portion 34 that raises and lowers the separation unit 152. This allows for an inexpensive configuration without increasing the number of parts.

[0084] <Mechanical components - lower side> 4, a feed roller cover 130 is provided on the transport path T side of the feed roller 151, and a guide member 131 and a rotating member 32 are provided on the transport path T side of the feed roller cover 130 so as to form a transport surface. The guide member 131 arranged on the upstream side is supported rotatably about the shaft A4, and the rotating member 32 arranged on the downstream side is supported rotatably about the shaft A6.

[0085] As shown in Fig. 4, guide member 131 is located upstream of the nip between feed roller 151 and separation roller 153, and has a placement surface f1 on which the downstream end of document Sh can be placed before the document is taken into the device body. As shown in Fig. 6, placement surface f1 can be held at a standby position P5 located above feed roller 151, and at a transport position P6 located below feed roller 151, as shown in Figs. 7 to 10.

[0086] 4, the rotating member 32 includes an extension 321, and a contact portion 1311 that contacts the extension 321 is provided on the guide member 131 of the feed roller cover 130. The guide member 131 is biased by the document table spring (biasing member) 20d in a direction in which the placement surface f1 moves away from the transport path T, and when the guide member 131 and the extension 321 are in contact with each other, the rotating member 32 is biased in the direction D7 by the document table spring 20d.

[0087] A rotating cam 33, which rotates by receiving the drive of the driving source 18b, is installed in the housing 10 below the rotating member 32 and is rotatable about the shaft portion A7 as a rotation axis. The rotating cam 33 rotates between a standby position P7 shown in FIG. 6(a) and a transport position P8 shown in FIG. 10(a), and is biased in the direction D5 by a rotating cam spring (biasing member) 20f. When the rotating cam 33 is at the standby position P7 as shown in FIG. 6(a), the rotating cam 33 abuts against the rotating member 32 and pushes the rotating member 32 upward. In addition, the extension portion 321 of the rotating member 32 abuts against the abutment portion 1311 of the guide member 131, and holds the guide member 131 at the standby position P5.

[0088] 10(a), when the rotating cam 33 is at the transport position P8, the rotating cam 33 separates from the rotating member 32, and the rotating member 32 is held at a position where it abuts against an abutment (not shown) due to its own weight. At this time, the abutment between the abutment portion 1311 of the guide member 131 and the extension portion 321 of the rotating member 32 is also released, and the guide member 131 is urged in the D7 direction by the document table spring 20d (FIG. 4), and is held at the transport position P6 where it abuts against an abutment (not shown). In this embodiment, the document table spring 20d is used to urge the guide member 131 in the D7 direction, but a configuration in which a force in the D7 direction is generated by the weight of the guide member 131 or the weight of the document Sh may also be used.

[0089] In this embodiment, the rotating cam 33 rotates by receiving drive from the driving source 18b via the drive transmission unit 19b. A one-way clutch is arranged in the drive transmission unit 19b, and the drive is transmitted to the rotating cam 33 when the driving source 18b rotates in the reverse direction, and the drive is cut off when the driving source 18b rotates in the forward direction. As a result, when the driving source 18b is rotated in the reverse direction as shown in FIG. 6(a), the rotating cam 33 receives the drive of the driving source 18b and rotates in the D5' direction. By stopping the rotation of the rotating cam 33 when it reaches the standby position P7, the guide member 131 can be maintained in the standby position P5.

[0090] On the other hand, when the driving source 18b rotates forward when the transport of the document Sh begins, the driving force to the rotating cam 33 is cut off, so that the rotating cam 33 rotates in the direction D5 by the biasing force of the rotating cam spring 20f until the abutment 331 abuts against a rotation stopper (not shown). The abutment between the rotating cam 33 and the rotating member 32 and the abutment between the rotating member 32 and the guide member 131 are both released, and the guide member 131 rotates by the document table spring 20d until it is located at the transport position P6.

[0091] 6(a), the rotating member 32 forms a gap G1 between the guide member 131 and the rotating member 32, into which the document stopper 173 in the upright position can fit. That is, while the arm portion 171 is in the standby position P1, the document stopper 173 is held by fitting into the edge portion that forms the gap G1.

[0092] 6, when the document Sh is set on the guide member 131, in addition to the biasing force of the stopper spring 20c, a force in the direction D3 due to the weight of the document Sh is applied to the document stopper 173. If the document stopper 173 is not strong enough and bends in the direction D3, the document Sh will move downstream and enter the nip between the feed roller 151 and the separation roller 153.

[0093] Furthermore, if the thickness or width of the document stopper 173 is increased to prevent the document stopper 173 from bending, it is necessary to increase the size of the device body to prevent interference between the document stopper 173 and surrounding components. On the other hand, in this embodiment, the tip of the document stopper 173 fits into the edge of the gap G1, so that the document stopper 173 can be prevented from bending without increasing the thickness or width of the document stopper 173. Therefore, the tip of the document Sh can be restricted to an appropriate position without increasing the size of the device.

[0094] <Up and down timing adjustment> In this embodiment, by appropriately controlling the timing at which the arm unit 171 and the rotating member 32 rotate and the timing at which the paper feed roller 151 starts to rotate, the leading edge of the document Sh can be made to follow the document stopper 173 without applying a load to the document Sh, and the document Sh can be sent to the nip between the paper feed roller 151 and the separation roller 153 in the correct order. The operation of each part when paper feed starts and the configuration that realizes this operation are described below in chronological order.

[0095] Fig. 6 is a diagram showing the initial state of the device before the start of paper feeding. This is the state before step S1010 in the flowchart of Fig. 3 described above, and shows the state in which both drive sources 18a and 18b are stopped. As described above, cam shaft 30 is at standby position P3, which causes arm portion 171 to be at standby position P1, document stopper 173 to be in an upright position, and separation roller 153 to be separated from paper feed roller 151. Also, guide member 131 is at standby position P5 protruding further toward transport path T than paper feed roller 151.

[0096] 7 is a diagram showing the state immediately after the start of the paper feed operation, which is midway through the operation of step S1040 in the flowchart of FIG. 3, and shows the state immediately after the driving source 18b starts to move.

[0097] In the state of Fig. 7, compared to the state of Fig. 6, the cam shaft 30 is driven by the drive source 18b and rotates in the D4 direction, but the arm portion 171 remains at the standby position P1, and the position of the document stopper 173 that moves in conjunction with the arm portion 171 does not change. As described above, the arm support portion 31 of the cam shaft 30 abuts on the arm holding portion 175 of the arm portion 171 to hold the arm portion 171 at the standby position P1, but in the state shown in Fig. 6(a) and Fig. 7(a), the arm support portion 31 of the cam shaft 30 abuts on the arc portion 175a of the arm holding portion 175 of the arm portion 171. The arc portion 175a is arranged so that the center of the arc shape coincides with the center of the rotation axis A5 of the cam shaft 30 when the arm portion 171 is at the standby position P1. 6(a) and 7(a), the arm portion 171 does not move in conjunction with the rotation of the camshaft 30 and remains in the standby position P1.

[0098] 8, the separation unit 152 rotates until the separation holder holding portion 155 and the separation holder support portion 34 of the cam shaft 30 are released and the separation roller 153 comes into contact with the feed roller 151. Thus, according to this embodiment, the separation unit 152 rotates prior to the rotation of the arm portion 171 and the document stopper 173. Therefore, while the feed roller 151 and the separation roller 153 are separated from each other, the document Sh moves downstream, and the document Sh is not inserted as a bundle into the nip between the feed roller 151 and the separation roller 153.

[0099] 7, the rotating cam 33 rotates in the direction D5 by being driven by the driving source 18b, and the rotating member 32 in contact with the rotating cam 33 rotates in a direction retracting from the transport path T. The guide member 131 rotates until it is released from contact with the rotating member 32 and reaches the transport position P6. Thus, according to this embodiment, the rotating member 32 and the guide member 131 rotate before the arm portion 171 rotates, and the engagement between the edge of the gap G1 and the document stopper 173 shown in FIG. 6(a) is released. Therefore, when the arm portion 171 rotates, the document stopper 173 does not get caught on the edge of the gap G1, preventing the arm portion 171 from rotating.

[0100] 8 shows a state in which the driving source 18b has rotated further than in FIG. 7, and represents the state between steps S1040 and S1050 in the flow chart of FIG.

[0101] Compared to the state in FIG. 7, the cam shaft 30 is driven by the drive source 18b and rotates in the direction D4, the arm support portion 31 of the cam shaft 30 abuts against the inclined surface portion 175b of the arm portion 171 instead of the arc portion 175a, and the arm portion 171 rotates in the direction D6. As a result, the document stopper 173 rotates in the direction D3 and releases the transport path T. In this manner, according to this embodiment, the document stopper 173 releases the transport path T before the feed roller 151 starts to rotate. Therefore, the document Sh is pushed downstream with the transport path T blocked by the document stopper 173, and the leading edge of the document Sh is not damaged.

[0102] Fig. 9 shows a state in which the driving source 18b has rotated further than in Fig. 8, and represents a state in which the driving source 18a has started to move during the operation of step S1050 in the flowchart of Fig. 3. The paper feed roller 151 rotates in the D1 direction by the driving source 18a, and the document Sh is pressed against the paper feed roller 151 by its own weight and begins to be taken into the device body. Compared to the state in Fig. 8, the cam shaft 30 rotates in the D4 direction by the driving source 18b, and the arm portion 171 rotates to a position where the pick roller 172 contacts the document Sh.

[0103] However, because the arm support portion 31 and the arm holding portion 175 of the arm portion 171 are in contact with each other, the pressing force of the pick spring 20b is received by the arm support portion 31, and the pick roller 172 is not pressing the document Sh. Furthermore, when the cam shaft rotates further in the D4 direction, the pick roller 172 presses the document Sh against the feed roller 151, and the document Sh is stably transported downstream.

[0104] 9(a), if multiple pick rollers 172 arranged in the left-right direction do not simultaneously come into contact with the document Sh and start pressing the document Sh against the feed roller 151, this can cause the document Sh to skew. In this embodiment, the arm support portion 31 of the cam shaft 30 supports the arm holding portions 175 at both left-right ends of the arm portion 171, so that the arm portion 171 descends without tilting and the left and right pick rollers 172 come into contact with the document Sh at the same time, preventing the document Sh from skewing when it is fed.

[0105] FIG. 10 is a diagram showing a state in which all of the documents Sh on the guide member 131 have been taken into the apparatus main body, and shows a state midway through the operation of step S1060 in the flow chart of FIG.

[0106] The camshaft 30 rotates until the abutment 312 (see FIG. 5) abuts against a rotation stopper (not shown), and the abutment between the camshaft 30 and the arm portion 171 is released. In addition, the rotating cam 33 rotates until the abutment 331 abuts against a rotation stopper (not shown).

[0107] 10(a), if the multiple pick rollers 172 arranged in the left-right direction do not press the document Sh against the paper feed roller 151 with the same force, it will cause the document Sh to skew. In this embodiment, since the pick springs 20b are arranged in the engagement parts 176, the forces with which the left and right pick rollers 172 press the document Sh against the paper feed roller 151 are equalized, and skew of the document Sh can be prevented when the document Sh is taken into the device body.

[0108] In this embodiment, when driving source 18b is rotated forward from the state shown in Fig. 6, camshaft 30 and rotating cam 33 start rotating at the same time, come into contact with the rotation stopper at the same time, and stop rotating, resulting in the state shown in Fig. 10. Therefore, when driving source 18b is rotated in the reverse direction in step S1090 of the flowchart shown in Fig. 3 to return the device to the initial state, the state shown in Fig. 10 goes from the state shown in Fig. 9, the state shown in Fig. 8, and the state shown in Fig. 7, and then returns to the state shown in Fig. 6.

[0109] <Nip width> FIG. 11 is a diagram showing the intake port 14 of the document feeder 1 according to the present embodiment as viewed from the upstream side of the transport path of the document Sh, and shows a variation of the embodiment for carrying out the present invention.

[0110] As described above, in this embodiment, when the arm unit 171 is at the standby position P1, the arm holding unit 175 of the arm unit 171 is supported by the arm support unit 31 of the cam shaft 30. In addition, the contact points 40 of the arm holding unit 175 and the arm support unit 31 are disposed on both sides of the center in the document width direction (the center of the nip between the feed roller 151 and the separation roller 153). Here, when the distance between the contact points 40 in the document width direction is L1 and the nip width between the feed roller 151 and the separation roller 153 is L2, the contact points 40 are disposed so that L1>L2. The nip width is the width of the nip between the separation roller 153 and the feed roller 151. Since there are multiple nips in this embodiment, the nip width is L2 including the distance between the rollers.

[0111] In order to prevent a difference in the pressing force of the pick roller between the left and right sides, it is desirable to make the distance in the document width direction between the farthest pick springs among those pick springs that generate the pressing force of the pick roller larger than the nip width.

[0112] 11(a), for example, the distance L1 between the contact points 40 of the arm holding portion 175 and the arm support portion 31 is greater than the width between the outer sides of the feed roller 151, and is also greater than the width between the outer sides of the separation roller 153. Therefore, the distance L1 between the contact points is greater than the nip width L2 between the feed roller 151 and the separation roller 153.

[0113] Also, when the distance L1 between the contact points 40 of the arm holding portion 175 and the arm support portion 31 is smaller than the width between the outsides of the paper feed rollers 151 and larger than the width between the outsides of the separation rollers 153, as in FIG. 11(b), or when the distance L1 is larger than the width between the outsides of the paper feed rollers 151 and smaller than the width between the outsides of the separation rollers 153, as in FIG. 11(c), the distance L1 is larger than the nip width L2.

[0114] This arrangement makes it possible to prevent the pick roller 172 from being pressed or raised and lowered in a tilted state relative to the feed roller 151. Also, when the separation holder holding part 155 rotates, there is no interference between the arm support part 31 and the feed roller 151 or separation roller 153. Furthermore, since only the rotation axis A5 of the cam shaft 30 needs to be disposed above the separation roller 153, the height of the device can be reduced.

[0115] According to this embodiment, the arm support portion 31 of the cam shaft 30 supports the arm holding portions 175 at both left and right ends of the arm portion 171, so that the arm portion 171 can be lowered without tilting, and the left and right pick rollers 172 can simultaneously touch the document Sh. In addition, because the pick spring 20b is arranged in the engagement portion 176, the force with which the left and right pick rollers 172 press the document Sh against the feed roller 151 becomes uniform, and it is possible to prevent the document Sh from skewing when the document Sh is taken into the device main body.

[0116] In addition, in this embodiment, the arm support parts 31 at both ends of the axial direction of the camshaft 30 are integrally provided, so that the number of parts is not increased and a relatively inexpensive configuration can be implemented. Furthermore, in this embodiment, only the rotation axis A5 of the camshaft 30 needs to be disposed above the arm part 171 and the separation unit 152. Therefore, the height of the device main body can be reduced.

[0117] In this embodiment, each element is named based on its main function, but the functions described in the embodiment may be sub-functions and are not strictly limited to those expressions. Furthermore, those expressions can be replaced with similar expressions. In the same spirit, the expression "unit, part" may be replaced with "component," "member," "structure," "assembly," etc., or may be omitted.

[0118] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

[0119] For example, in the above embodiments, the driving sources 18a and 18b shown in Fig. 1 are described as separate driving sources, but they may be configured as the same driving source. In that case, a clutch for interrupting the transmission of the driving force or a delay mechanism for delaying the transmission of the driving force may be provided in the drive transmission path from the driving source to each roller or the like.

[0120] As described above, the timing of the transmission of the drive from the drive source 18b to the arm portion 171 and the separation unit 152 can be adjusted. In this embodiment, the timing is adjusted by the shape of the engagement portion (separation holder holding portion 155, arm holding portion 175) with the camshaft 30, but the arm portion 171 and the separation unit 152 may be rotated by different mechanisms or drives. Also, the separation holder support portion 34 of the camshaft 30 and the arm support portion 31 may be provided on different members having a coaxial rotation shaft instead of being integral, in which case the shafts may be engaged with each other with a backlash in the rotation direction, and a configuration may be adopted in which there is a time for the shafts to rotate idly when the drive is transmitted. Alternatively, this may be realized by other elements such as a clutch mechanism or a lock mechanism.

[0121] In the above embodiment, the rotation axis A5 of the cam shaft 30 for raising and lowering the arm portion 171 is provided above the separation roller 153, but it may be disposed on the feed roller 151 side as shown in FIG. 11(c).

[0122] In this embodiment, the drive of the feed roller 151 starts after the document stopper 173 is in a tilted position (a state in which the intake port 14 is open), but this is not limited to this. In other words, it is sufficient if the document Sh comes into contact with the rotating feed roller 151 and is prevented from being pressed against the document stopper 173 when there is no gap between the document stopper 173 and the feed roller 151 for the document Sh to pass through. Therefore, the timing of starting the drive can be adjusted within a range that does not deviate from this purpose.

[0123] As another embodiment for moving the separation unit 152 away from the feed roller 151, the arm portion 171 may be retreated to the standby position P1, and then further rotated in the direction D6' shown in Fig. 6(a) etc. to move the separation unit 152 away from the feed roller 151 via the arm portion 171. However, since the movable range of the arm portion 171 is reduced when the shape for moving the arm portion 171 and the separation unit 152 away from the conveying path T is integrally provided on the cam shaft 30 as in this embodiment, the height of the device body can be reduced.

[0124] In addition, in this embodiment, the control unit 23 drives the driving source 18b to rotate the guide member 131, but in other embodiments, the guide member 131 may be mechanically configured to rotate in conjunction with the rotation of the arm portion 171.

[0125] For example, the guide member 131 may be linked to the arm portion 171 by a link mechanism, and may rotate together with the arm portion 171 when the arm portion 171 rotates from the standby position P1 to the transport position P2. Also, the guide member 131 may be configured to be driven by separate drive sources for the respective drive portions.

[0126] In addition, in this embodiment, the guide member 131 is pushed out toward the transport path T by the cam and retracted from the transport path T by the document table spring 20d, but the configuration may be such that the opposite direction occurs. That is, the guide member 131 may be pushed up toward the transport path T by the biasing force of the document table spring 20d, and the guide member 131 may be pushed down in a direction retracting from the transport path T by the engagement of the cam member.

[0127] As described above, it is possible to adjust the timing of the drive power transmission from the drive source 18a to the paper feed roller 151. This may be achieved by the drive control of the drive transmission unit 19a as described in the above embodiment, or may be achieved additionally or alternatively by, for example, a clutch mechanism, a lock mechanism, or the like.

[0128] (Appendix 1) a paper feed roller for extracting and transporting a document from a document stack consisting of a plurality of documents; a separating means for forming a nip with the paper feed roller and separating the document one by one, 2. An image reading apparatus according to claim 1, wherein the separating means is movable between a position of the nip and a standby position spaced from the position of the nip.

[0129] (Appendix 2) a document stopper for restricting the taking-in of the document; a pick arm unit that conveys the document to the nip by pressing the document against the paper feed roller, the pick arm unit is movable between a transport position where it protrudes toward the feed roller and the document and a standby position where it is spaced apart from the feed roller and the document, The pick arm unit and the separating means are moved by a rotatable cam member, The image reading device according to claim 1, wherein the cam member is made of a single material.

[0130] (Appendix 3) 3. The image reading device according to claim 2, wherein the cam member that moves the pick arm and the cam member that moves the separating means have different shapes.

[0131] (Appendix 4) The image reading device described in Appendix 2 or 3, characterized in that the separation means is maintained separated from the paper feed roller by a separation holder support portion formed on the cam member when paper is not being fed, and when paper is being fed, the separation means rotates until it contacts the paper feed roller before the document stopper rotates from an upright position to an inclined position. [Explanation of symbols]

[0132] Sh Manuscript 1 Document feeder 10. Chassis 11 Outlet 12 Output tray 13 Loading Tray 130 Feed roller cover 131 Guide member 1311 Contact part 14 Intake port 15 Transport mechanism 151 Paper feed roller 152 Separation Unit 153 Separation roller 154 Separate holder 155 Separate holder holding part 156 Locking part 16 Reading unit 17 Pick arm unit 171 Arm section 172 Pick Coro 173 Document stopper 1731 Locking part 174 Housing holder 175 Arm holder 175a Arc section 175b Slope 176 Engagement part 20a Separation spring 20b Pick spring 20c Stopper spring 20d Document bed spring 20e Camshaft spring 20f Rotating cam spring 30 Camshaft 31 Arm support part 311 Lever shape 312 End 32 Rotating member 321 Extension part 33 Rotating Cam 331 End 34 Separate holder support part 341 Lever shape 40 Contacts

Claims

1. a feed roller for extracting and transporting a document from a document stack; a separating means for forming a nip with the paper feed roller and separating the document sheets one by one; a pick arm unit that conveys the document to the nip by pressing the document against the paper feed roller; a camshaft having a plurality of arm supports; having the pick arm unit is movable between a transport position where it protrudes toward the feed roller and the document and a standby position where it is spaced apart from the feed roller and the document, The document feeder, wherein the arm support sections support the pick arm unit and hold the pick arm unit at the standby position.

2. The separation means is rotatably held by a separation holder, 2. The document feeder according to claim 1, wherein the separation holder is rotatably held by a housing.

3. The separation holder includes a separation holder holding portion, 3. The document feeding device according to claim 2, wherein the cam shaft has a separation holder support portion that engages the separation holder holding portion, and rotates the separation means in a direction to separate the separation means from the paper feed roller.

4. The pick arm unit has an engagement portion, 3. The document feeder according to claim 2, wherein the engagement portion is disposed on the housing so as to be rotatable coaxially with the separation holder.

5. the pick arm unit has a plurality of arm holding parts supported by the plurality of arm support parts, The document feeding device according to claim 1, characterized in that the multiple arm support parts are each rotatable around a rotation axis and are arranged in a line in the document width direction, and the distance in the document width direction between the contact points of the multiple arm support parts and the multiple arm holding parts that are located furthest away in the document width direction is greater than the nip width.

6. 6. The document feeder according to claim 5, wherein the arm holders each have an arcuate portion that is concentric with the rotation shaft.

7. 6. The document feeding device according to claim 5, further comprising: a plurality of biasing members arranged in the document width direction to generate a pressing force for pressing the pick arm unit against the paper feed roller; and a distance in the document width direction between the farthest biasing members among the plurality of biasing members is greater than the nip width.

8. 6. The document feeder according to claim 5, wherein the rotation shaft is located at a position farther away from the document transport path than the pick arm unit in the standby position.

Images