JP4816964B2 - Document feeder - Google Patents

Description

  The present invention relates to a document conveying device having a so-called automatic document conveying mechanism.

  Conventionally, as a document conveying device of an image reading device (such as a copying device, a scanner device, or a multi-function device in which these are arranged in parallel) that reads an image of a document, an automatic document that reads a conveyed document with a stationary image reading means One having a transport mechanism (ADF: Auto Document Feeder) is known.

  In such an automatic document conveyance mechanism, in order to convey the document, a detection sensor for detecting the document is provided along the conveyance path. For example, in Patent Document 1, a separation roller that conveys the originals placed on the paper feed tray one by one to the reading unit is provided opposite to the paper feed tray, and the upstream side of the separation roller in the document conveyance direction. Detection sensors are arranged at two locations on the downstream side. The upstream detection sensor detects that the original is placed on the paper feed tray, and the downstream detection sensor detects the leading or trailing edge of the original fed to the reading unit by the separation roller. is doing.

Both of the two detection sensors of Patent Document 1 have the same structure, and the detection pieces of the detection sensor appear from the bottom to the top of the opening formed in the bottom surface of the paper feed tray serving as a conveyance path. It protrudes as possible, and the photo interrupter is blocked at the lower part of the detection piece. The detection piece is urged in a direction protruding upward from the opening, but the urging force is set to such an extent that the detection piece can be easily retracted (sunk) to the opening side when the document comes into contact. Yes. Then, when the detection piece is rotated by the document so as to be retracted to the opening, this rotation is detected by the photo implanter.
JP 2007-223703 A (see FIGS. 2 and 5)

  In the automatic document transport mechanism, the document is often placed on the sheet feeding tray with the center aligned. For this reason, in consideration of cost reduction and the like, the separation roller and the cover body covering the separation roller are often arranged at the center position in the width direction of the paper feed tray (direction perpendicular to the document transport direction). Therefore, if the detection sensor described in Patent Document 1 is arranged outside in a plan view with respect to the cover body that covers the separation roller, the document may cause a paper jam in the vicinity of the separation roller. There was a problem. In particular, this problem is likely to occur when the conveyed document is thinner and less rigid (less elastic) than ordinary copy paper. More specifically, as shown in FIG. 7, when the original G2 is thin and has low rigidity as described above, the detection piece 141 protruding from the original placement surface 14c of the paper feed tray 14 is sufficiently provided in the opening 122. It cannot be evacuated to the inside. Therefore, there is a possibility that the thin original G2 is lifted along the detection piece 141 and is caught on the peripheral members such as the drive shaft 31 of the separation roller 30 and the original is jammed (original jam).

  Furthermore, when the detection piece 141 as described in Patent Document 1 is arranged outside in a plan view with respect to the cover body 32a covering the separation roller 30, the above-described thin paper, curling, There is also a problem that when a document with a large gap is conveyed, the document floats at the position of the detection piece 141 and the placed document cannot be detected by the detection sensor.

  In addition, when the detection piece 141 is arranged outside the cover body in a plan view, that is, at a position not covered with the cover body, when a housing cover (not shown) for jamming of the paper feed tray 14 is opened. The user may touch the detection piece 141 with his / her hand. Then, in the case where the electric circuit board is arranged inside the document conveying measure near the lower part of the detection piece 141, there is a possibility that the user touches the detection piece 141 to cause electrostatic breakdown of the electric circuit board. there were.

  Further, since the opening 122 for projecting the detection piece 141 formed in the document placing surface 14c of the sheet feeding tray 14 is exposed, dust or the like is introduced into the document conveying apparatus from the opening. It becomes easy to enter. Then, when the electric circuit board is disposed in the vicinity of the opening, there is a problem that the electric circuit board may be destroyed due to a short circuit.

  The present invention solves the above problem, and even when a detection unit having a detection piece in contact with the document is provided in the feeding unit for conveying the document to the reading unit side, An object of the present invention is to realize a document conveying device that can reliably convey a document while preventing troubles such as clogging.

  In order to achieve the above object, the document feeder according to the first aspect of the present invention transfers a document from a paper feed unit that feeds the document to a paper discharge unit that discharges the document through a reading unit that reads the document. An original conveying apparatus configured to convey an original, a document placing table having a document placing surface on which at least one document is placed, and a part of the document placing table. A separation roller which is arranged so as to be in contact with the original placed on the original placement surface, overlapping in plan view, and driven so as to separate the original one by one and transport it to the reading unit side; Detecting means for detecting a document placed on the document placement surface and conveyed by the separation roller, the detection piece having a detection piece that can be projected and retracted with respect to a hole provided in the document placement surface; An opening that exposes the separation roller so as to be in contact with the document placement surface; And a cover body that covers at least a side opposite to the side facing the document placement surface of the separation roller, and the detection piece is disposed inside the cover body in a plan view. It is a feature.

  According to a second aspect of the present invention, in the document conveying device according to the first aspect, the separation roller is pivotally supported by a drive shaft extending in a direction orthogonal to the document conveying direction, and the separation roller and the cover body are supported. Is characterized in that it is partially disposed on the substantial center of the document placement surface in the direction orthogonal to the document transport direction.

  According to a third aspect of the present invention, in the document conveying device according to the first or second aspect, the cover body is rotatably attached to the drive shaft and extends in the document conveying direction. The detection piece is arranged inside the side plate.

  According to a fourth aspect of the present invention, in the document conveying device according to any one of the first to third aspects, the cover body is formed in an arm shape extending from the drive shaft side to the upstream side in the document conveying direction. A suction roller that contacts the document placed on the document placement surface is rotatably attached to the cover body upstream of the separation roller in the document transport direction. To do.

  According to a fifth aspect of the present invention, in the document conveying device according to any one of the first to fourth aspects, at least a region on the downstream side in the document conveying direction of the document table including the region overlapping the cover body is It is characterized by being covered with an openable / closable lid.

  According to the first aspect of the present invention, the detection means for detecting the document placed on the document placement surface of the document placement table is a detection piece capable of appearing and retracting with respect to a hole provided in the document placement surface. The detection piece is disposed inside the cover body that covers at least the upper surface of the separation roller in a plan view. Therefore, when the original is thin and the rigidity is small, even if the original that comes into contact with the detection piece is likely to lift, the cover body provided on the upper surface side of the detection piece can suppress the lift of the original. Paper jams (paper jams) caused by the original floating near the separation roller (paper feeding unit) are less likely to occur.

  Further, by preventing the document from lifting up, the reliability of the operation in which the document comes into contact with the detection piece and retreats it into the hole is improved, so that the detection piece does not rotate despite the presence of the document. It is possible to prevent detection errors caused by the detection errors and improve detection accuracy.

  Further, since the upper surface of the detection piece is blocked by the cover body, the user cannot easily touch the detection piece. Therefore, even if the electric circuit board is arranged in the vicinity of the detection piece inside the document conveying device, there is no possibility of causing electrostatic breakdown of the electric circuit board through the detection piece.

  Furthermore, a hole for projecting the detection piece opens in the document placement surface, but the upper surface of this hole is also covered with the cover body, so there is a risk that foreign matter, dust, or the like may enter the hole. And the effect of preventing a short circuit of the electric circuit board due to foreign matter or dust can be enhanced.

  According to the second aspect of the present invention, the separation roller and the cover body are partially in a direction perpendicular to the document transport direction on the document placement surface, that is, substantially in the center in the width direction of the document placement surface. Has been placed. Therefore, when the document is aligned with the center portion in the width direction of the document placement surface by so-called center alignment, the separation roller contacts the center portion in the width direction of the document regardless of the size of the document. And the detection piece arrange | positioned inside the cover body can also contact | abut to a document reliably.

  According to the invention described in claim 3, the cover body has the side plate extending in the document conveying direction. By providing the side plate on the cover body, the lower end of the side plate can be brought closer to the document placement surface, so when the document is about to float along the detection piece, the side plate arranged near the detection piece Lifting can be prevented more reliably. In particular, as described in claim 2, when the cover body is arranged at the center of the document placement surface in the width direction, the distance between the detection piece covered by the cover body and the side plate of the cover body becomes short. Therefore, the original that is about to float by the detection piece can be suppressed by the side plate in the vicinity thereof, and the effect of preventing paper jam is enhanced.

  According to the fourth aspect of the present invention, the suction roller that contacts the document placed on the document placement surface is rotatable upstream of the separation roller in the arm-shaped cover body in the document conveyance direction. It is attached. That is, the suction roller abuts on the top surface of one or a plurality of documents placed on the document placement surface, and the separation roller separates only one document on the top surface and conveys it to the reading unit side. It is composed. If the detection piece is arranged between the separation roller and the suction roller, it can be detected whether or not the document to be conveyed by the separation roller is placed on the document placement surface, and the detection piece is arranged immediately downstream of the separation roller. The leading edge or trailing edge of the document conveyed by the separation roller can be detected. That is, even if the detection piece is arranged at a position covered by the cover body, the detection purpose can be changed according to the positional relationship with the separation roller.

  According to the fifth aspect of the present invention, at least the downstream area in the document transport direction on the document placement surface including the area overlapping the cover body is covered with the lid, but the lid can be opened and closed. Is provided. Therefore, in a normal use state, not only the cover body but also at least the downstream area in the document transport direction is covered with the lid body, and thus the user cannot easily touch the hand. When it is necessary to open the lid, the user can touch the part covered with the lid, but the detection piece is arranged inside the cover in plan view. The possibility that the user will accidentally touch is extremely low, and the possibility of causing electrostatic breakdown of the electric circuit board as described above is very small.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The present embodiment shows an image reading device 2 provided with a document conveying device 1, and FIG. 1 is an external perspective view of the image reading device 2. The image reading apparatus 2 is applied to an image reading unit of a multi function device (MFD) having a plurality of functions such as a facsimile function, a copy function, a printer function, and a scanner function. The present invention may be applied to a single scanner device, a copy device, and a facsimile device. In FIG. 1, only the image reading device 2 of the multi-function device is illustrated, and the other portions are not illustrated.

  The image reading device 2 is arranged at the upper part of the main body of the multi-function device, and the uppermost surface of the image reading device 2 is first rotatable up and down via a hinge (not shown) provided on the back side (back side in FIG. 1). The lid 4 is attached, and an automatic document feeder (ADF) that is the document feeder 1 is provided on one side (left side in FIG. 1) of the first lid 4.

  Although not shown, an operation unit including buttons and buttons for performing various operations and a panel display unit such as a liquid crystal is provided on the front side of the image reading device 2 (front side in FIG. 1). The image reading device 2 (multifunctional device) is connected to an external device such as a computer. Accordingly, the image reading apparatus 2 is operated by a command from a user using the operation unit or a command from an external device such as a computer.

  At the center of the upper surface exposed when the first lid 4 is opened, as shown in FIGS. 2 and 4, a rectangular transparent glass plate 5 for reading a stationary document, and the document conveying device 1 A transparent glass plate 6 that is elongated in the X-axis direction for reading the original document conveyed in (1) is juxtaposed. Below the glass plates 5 and 6, an image reading means 7 is disposed so as to be reciprocally movable in the Y-axis direction.

  The image reading means 7 is a so-called line image sensor that irradiates a document with light from a light source through the glass plate 5 or the glass plate 6 and condenses the reflected light from the document on a light receiving element by a lens and converts it into an electrical signal. The image reading means 7 is provided long in the Y-axis direction of FIGS. 1 and 2, and is provided so as to be capable of reciprocating in the Y-axis direction along a guide shaft (not shown) by a known traveling mechanism. Although the CIS (Contact Image Sensor) is applied to the image reading means 7, a CCD (Charge Coupled Devise) may be used.

  When the image reading device 2 is used as a flat bed scanner (FBS) and reads a stationary document placed on the glass plate 5, the image reading means 7 extends below the glass plate 5 in the Y-axis direction. Read the document while moving. On the lower surface of the first lid 4, there is provided a presser plate 8 made of a sponge, a white plate, or the like for pressing the document toward the glass plate 5 when the first lid 4 is closed.

  On the other hand, when the document conveying device 1 is used in the image reading device 2, the image reading means that holds the document conveyed along the conveying path 13 of the document conveying device 1 below the glass plate 6. Read by 7. That is, in the document conveying apparatus 1, the position of the glass plate 6 is the reading unit 11 (reading position), and in the reading unit 11, the conveyance path 13 is formed so as to expose the reading surface of the document on the glass plate 6. ing. The reading unit 11 is also provided with a guide body 25 that is elastically biased so as to press the document toward the glass plate 6 side.

  The document transport device 1 includes a paper feeding unit 10 that feeds a document, the reading unit 11 described above, and a paper discharge unit 12 that discharges the document after reading. Since the reading unit 11 is at the lowest position (position facing the glass plate 6) and the paper feeding unit 10 is located above the paper discharging unit 12, the conveyance path 13 is connected to the document conveyance device 1. Inside, it is formed in a substantially U-shape that is lateral in a side view.

  In addition, a second lid 16 having a rotation center on one side surface (the left side in FIG. 1 and the right side in FIG. 3) of the first lid 4 is formed on the upper portion of the document conveying device 1 so as to be openable and closable. ing. The second lid body 16 extends from one side surface side of the first lid body 4 toward the central portion side, and the tip of the second lid body 16 extends in the document transport direction (hereinafter referred to as “paper feed tray 14”). It has reached a position covering the downstream end (simply referred to as the transport direction).

  The paper feed unit 10 is provided with a paper feed tray (corresponding to a document placement table in the claims) 14 having a document placement surface 14c on which documents to be fed can be placed in a stacked state. In this embodiment, since the document placement surface 14c of the paper feed tray 14 is integrally connected to the members constituting the transport path 13, the region on the downstream side in the transport direction of the paper feed tray 14 is It can also be said to be an upstream region of the conveyance path 13.

  The document placement surface 14c of the paper feed tray 14 is provided with one side surface side of the first lid 4 on which the document conveying device 1 is disposed as a base end, and the opposite free end is higher than the base end. It is formed in an inclined shape so as to be located at In other words, the document placed on the document placement surface 14c is placed so as to be inclined so that the front end of the document is located below the rear end.

  The base end side of the paper feed tray 14 is covered with the second lid 16 as described above. A hinge portion 14a is provided at a midway portion in the longitudinal direction from the base end to the free end of the paper feed tray 14, and a half on the free end side of the paper feed tray 14 serves as a turn-back portion 14b and is rotated by the hinge portion 14a. It is made possible. As a result, when there is no need to use the paper feed tray 14, the folding portion 14b of the paper feed tray 14 is folded to cover the document placement surface 14c of the paper feed tray 14 to prevent contamination by dust, dust, or the like. can do.

  The paper feed tray 14 is provided with a pair of guide pieces 20 along the side edges of the document so that the interval in the Y-axis direction can be adjusted by a known interlocking mechanism 23. By moving the guide piece 20 by hand, it is possible to perform so-called center alignment in which the document is aligned with the center line in the width direction of the paper feed tray 14 (direction perpendicular to the transport direction).

  The paper discharge unit 12 is provided with a paper discharge tray 15 on which discharged documents can be placed in a stacked state. The paper discharge tray 15 is formed in a plane on the first lid 4 below the paper feed tray 14 with a gap.

  A plurality of rollers for transporting the document are arranged on the transport path 13 at appropriate intervals. A suction roller 34 and a separation roller 30, which will be described in detail later, are arranged in the paper feeding unit 11, a conveyance roller 35 is arranged in the middle of the conveyance path 13, and a discharge roller 36 is arranged in the paper discharge unit 12. ing. A driven roller 37 is disposed opposite to the discharge roller 36. Note that the number and configuration of the rollers arranged along the conveyance path 13 are not limited to the above-described embodiments, and can be appropriately changed as necessary.

  In addition, detection means (sensors) for detecting a document are appropriately disposed along the conveyance path 13, and the paper feed unit 11 detects that the document is placed on the paper feed tray 14. Detection means 40 (described in detail later) is arranged. In the middle of the conveyance path 13, a detection unit 50 that detects the leading edge and the trailing edge of the document by being rotated by the conveyed document is disposed. The detecting unit 50 can detect the size of the document.

  The separation roller 30 disposed in the paper feed unit 10 is provided to convey the document placed on the document placement surface 14c to the reading unit 11 side. The separation roller 30 is supported by a drive shaft 31 extending in a direction orthogonal to the transport direction, and is provided at an upper position facing a region on the downstream side of the paper feed tray 14 in the transport direction. The separation roller 30 is disposed at the center position in the width direction of the paper feed tray 14, and the length in the width direction of the separation roller 30 is set to be considerably shorter than the length in the width direction of the paper feed tray 14. . In other words, since the document is placed on the sheet feed tray 14 in a centered manner, the separation roller 30 is disposed at the center position in the width direction of the sheet feed tray 14 so that the separation roller 30 can be reliably secured regardless of the size of the document. Can be brought into contact with the document.

  The roller surface of the separation roller 30 is made of a material that elastically contacts the document placement surface 14 c of the paper feed tray 14, while the portion of the document placement surface 14 c that faces the separation roller 30 has friction. A separation pad 45 having high resistance is provided. Even if a plurality of documents are stacked on the document placement surface 14c of the paper feed tray 14, the separation roller 30 can separate only one uppermost document by the frictional resistance and convey it to the reading unit 11 side. it can.

  The separation roller 30 is covered with a cover body 32 that is rotatably attached to the drive shaft 31. Similar to the separation roller 30, the cover body 32 is disposed at the center position in the width direction of the paper feed tray 14, and the length in the width direction is set to be considerably shorter than the length in the width direction of the paper feed tray 14. Has been. The cover body 32 is formed in an arm shape extending from the drive shaft 31 to the upstream side in the transport direction, and has an opening 33 that exposes the separation roller 30 to the document placement surface 14c side. Specifically, the cover body 32 includes an upper plate 32a that covers the upper surface of the separation roller 30 (the side opposite to the side facing the document placement surface 14c), and left and right side plates 32b that extend along the transport direction. A front plate 32c that covers the front surface of the separation roller 30 on the downstream side in the transport direction. The lower ends of both side plates 32b are extended to a position closer to the document placement surface 14c than the drive shaft 31 at a position corresponding to the drive shaft 31, and so as to follow the inclined shape of the document placement surface 14c. It curves upward toward the upstream side in the transport direction and is connected to the edge of the upper plate 32a on the upstream side in the transport direction.

  A suction roller 34 is rotatably attached to the cover body 32 at a position upstream of the separation roller 30 in the transport direction. The suction roller 34 and the separation roller 30 are arranged so that their axes are parallel to each other, and are connected to the separation roller 30 by a gear (not shown). When the separation roller 30 rotates by the drive shaft 31, the suction roller 34 rotates in the same direction as the separation roller 30. Since the cover body 32 has the drive shaft 31 as a base end and the side to which the suction roller 34 is attached is a free end, the suction roller 34 is placed on the document placement surface 14c by the weight of the cover body 32 and the suction roller 34. In contact with the uppermost surface of one or a plurality of documents placed on the document.

  The detection means 40 provided in the paper feed unit 10 includes a detection piece 41 provided so as to protrude upward and downward from a hole portion 22 formed in the document placement surface 14c of the paper feed tray 14. The photo-implanter 42 is provided inside the document conveying device 1 and detects the displacement of the detection piece 41.

  The hole 22 formed in the document placing surface 14c is disposed inside the cover body 32 of the separation roller 30 in a plan view. Specifically, the hole 22 is covered with the upper plate 32a of the cover body 32 and both side plates. It is provided at a position corresponding to between the separation roller 30 and the suction roller 34 inside the region sandwiched by 32b. Therefore, the detection piece 41 protruding from the hole portion 22 is covered with the cover body 32 at the top.

  As shown in FIG. 5, the detection piece 41 is formed in an L shape in a side view, and a lower end portion of the detection piece 41 is pivotally supported inside the document conveying apparatus 1, and an upper end portion is formed. Becomes a free end and protrudes upward from the hole 22. The detection piece 41 is elastically biased upward by an elastic member such as a spring (not shown) on the side on which the original passes on the original placement surface 14c. The urging force of the elastic member is easily rotated in the direction in which the detection piece 41 is immersed in the hole 22 by a document (a copy sheet or other commonly used recording medium) that contacts the upper end of the detection piece 41. It is set to the extent that causes

  Further, the detection piece 41 is arranged so that the vicinity of the bent portion blocks between the light emitting portion and the light receiving portion of the photo interrupter 42. As a result, when the detection means 40 rotates in the direction in which the detection piece 41 is immersed in the hole portion 22 as shown in FIG. It is configured to detect that a light beam has reached the light receiving unit from the light emitting unit and the detection piece 41 has rotated.

  According to the above configuration, when placing a document on the document placement surface 14 c of the paper feed tray 14, the leading end of the document passes under the suction roller 34 and reaches a position where it contacts the separation roller 30. At this time, the document is placed so that the reading surface (document surface) is the upper surface. When the inserted document G1 comes into contact with the detection piece 41 of the detection means 40, as shown in FIG. 6A, a pressing force that retracts the detection piece 41 into the hole portion 22 acts. Is rotated downward, and this displacement can be detected by the photo implanter 42. Thereby, it is possible to detect that a document is placed on the document placement surface 14c of the paper feed tray 14 (whether or not a document is present).

  Then, when a document conveyance or reading is instructed manually or from an external device to the document conveyance device 1, the separation roller 30 rotates to separate only one document located on the uppermost layer and send it to the conveyance path 13. It is done. In the reading unit 11, the document is conveyed with the reading surface on the lower surface side, the document is read by the image reading means 7 on the glass plate 6, and the document passes through the paper discharge unit 12 with the reading surface facing the lower surface side. The paper is discharged to the paper discharge tray 15.

  If the original G2 placed on the original placement surface 14c of the paper feed tray 14 is thin and does not have sufficient rigidity to retract the detection piece 41 into the hole 22, the original G2 is detected. Lifting to avoid the piece 41 may occur. As shown in FIG. 7 described above, when the detection piece 41 is arranged outside the cover body 32, the edge of the document G2 that is lifted by the detection piece 141 is in a state of jumping up and is caught on the drive shaft 131 as it is. There is also a risk of document jamming (paper jam).

  In addition, when the original is thin paper, or when the original is curled or wrinkled, the detection piece 41 cannot be reliably pressed and rotated due to the rising of the original. An error (missing detection) may occur.

  However, in this embodiment, since the detection piece 41 is disposed inside the cover body 32 in plan view, the side plate 32b of the cover body 32 is provided in the immediate vicinity of the detection piece 41, and the lower end of the side plate 32b is It is closer to the surface of the paper feed tray 14 than the position of the drive shaft 31. Therefore, as shown in FIG. 6B, even if the original G2 is lifted by the detection piece 41, the side plate 32b immediately adjacent to the detection piece 41 acts to press the original G2 against the paper feed tray 14 side. Even in the case of the thin paper original G2, there is almost no possibility of being caught by the drive shaft 41, and it is effective in preventing paper jamming (paper jam).

  Further, by preventing the document from being lifted by the cover body 32, it is possible to increase the certainty of the pressing and rotating of the detection piece 41 by the document, so that detection errors can be suppressed and detection accuracy can be improved.

  In the normal use state, as shown in FIG. 4, the separation roller 30 is covered with the second lid 16, but when trouble such as paper jam occurs in the paper feeding unit 10, the second lid The body 16 needs to be opened and the user needs to touch the vicinity of the separation roller 30. In the present invention, the detection piece 41 of the detection means 40 and the hole 22 through which the detection piece 41 protrudes are provided in a portion hidden by the cover body 32 (see FIG. 3 with the lid removed), the user can Even if the lid 16 is opened and the inside thereof is touched, the possibility of touching the detection piece 41 itself is extremely low. When the electric circuit board is arranged near the lower part of the detection piece 41, there is a possibility that the user touches the detection piece 41 to cause electrostatic breakdown of the electric circuit board. Furthermore, by eliminating or reducing the possibility of the user touching the detection piece 41, the occurrence of electrical troubles can be prevented.

  Furthermore, since the detection piece 41 is arranged inside the cover body 32 in a plan view, and the hole 22 for projecting the detection piece 41 is also covered with the cover body 32, the detection piece 41 opens upward. It is also possible to prevent foreign matter and dust from entering the hole 22. As a result, the possibility of a short circuit of the electric circuit board due to foreign matter or dust can be greatly improved.

  In the above-described embodiment, as the detection unit that detects the document conveyed by the separation roller 30, the detection unit that detects the document placed on the document placement surface 14c of the paper feed tray 14 for conveyance by the separation roller. 40 was exemplified. However, the detection means is not limited to this, and the same structure as the detection means 40 at the position immediately downstream of the separation roller 30 and inside the cover body 32 in plan view, as in Patent Document 1. The second detection means may be provided to detect the leading edge or trailing edge of the document conveyed by the separation roller 30. Of course, both the second detection means and the detection means 40 described above may be provided in parallel, or only one of them may be provided.

1 is a schematic perspective view of an image reading apparatus equipped with a document conveying device of the present invention. It is an outline perspective view of the state where the 1st lid was opened. It is a top view in the state where the 2nd lid was removed. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. FIG. 5 is an enlarged cross-sectional view taken along line VV in FIG. 3. (A) is a schematic diagram of a cross section taken along line VIa-VIa in FIG. 3, and (b) is a diagram corresponding to (a) and a schematic diagram when a thin paper document is conveyed. It is a schematic diagram near the conventional separation roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Document conveying apparatus 2 Image reading apparatus 4 1st cover body 5 Glass plate 6 Glass plate 7 Image reading means 10 Paper feed part 11 Reading part 12 Paper discharge part 13 Carriage path 14 Paper feed tray 14c Original document placement surface 15 Paper discharge Tray 16 Second lid 22 Hole 30 Separation roller 31 Drive shaft 32 Cover body 32b Side plate 33 Opening 34 Suction roller 40 Detection means 41 Detection piece 42 Photoinplanter

Claims (5)

A document conveying device configured to convey a document from a paper feeding unit that feeds a document, through a reading unit that reads the document, to a paper discharge unit that discharges the document,
In the paper feeding unit,
A document placing table having a document placing surface on which at least one document is placed;
It is arranged so as to overlap a part of the document placing table in plan view and to contact the document placed on the document placing surface, and separates the documents one by one and conveys them to the reading unit side. A separation roller driven as
A detection means for detecting a document placed on the document placement surface and conveyed by the separation roller, the detection piece having a detection piece that can be projected and retracted in a hole provided in the document placement surface;
A cover body that has an opening that exposes the separation roller so as to come into contact with the document placement surface, and covers at least a side of the separation roller opposite to the side facing the document placement surface. And
The document conveying apparatus, wherein the detection piece is disposed inside the cover body in a plan view. The separation roller is pivotally supported by a drive shaft extending in a direction orthogonal to the document conveying direction,
2. The document conveying device according to claim 1, wherein the separation roller and the cover body are partially disposed on a substantial center of the document placement surface in a direction orthogonal to a document conveying direction. .   The cover body is rotatably attached to the drive shaft, has a side plate extending in a document transport direction, and the detection piece is disposed inside the side plate. Item 3. The document conveying device according to Item 1 or 2. The cover body is formed in an arm shape extending from the drive shaft side to the upstream side in the document conveying direction,
The suction roller contacting the document placed on the document placement surface is rotatably attached to the cover body upstream of the separation roller in the document transport direction. The document conveying apparatus according to any one of 1 to 3.   5. The at least downstream area in the document transport direction in the document table including the area overlapping the cover body is covered with an openable / closable lid body. Document transport device.

Images