JP2010064844A - Automatic document conveying device and image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the usability of an automatic document conveying device and an image reader. <P>SOLUTION: A document delivery port 123A is provided with a check mechanism 133 permitting documents to flow through in a forward direction from a paper delivery roller 131 to a delivery tray 123 and forbidding the documents to flow through in a reverse direction from the delivery tray 123 to the paper delivery roller 131. Consequently, even if a user tries to insert and place a document erroneously in the delivery tray 123, the document can not be inserted and placed on the delivery tray 123 due to the check mechanism 133. Even in an environment where an upper paper feeding side ADF (automatic document conveying device) and a lower paper feeding side ADF are mixed, the user can be prevented from placing the document to be read in a wrong tray. The usability of the automatic document conveying device can thereby be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automatic document feeder for an image reading apparatus and an image reading apparatus.

  As is well known, an automatic document feeder for an image reading apparatus automatically conveys a document placed on a document tray to a reading unit and discharges the document whose image reading has been completed to a discharge tray.

For example, in the invention described in Patent Document 1, the document tray is arranged below the discharge tray, or in the invention described in Patent Document 2, for example, the document tray is arranged above the discharge tray.
JP 2007-238252 A JP 2006-347684 A

  However, an image reading apparatus provided with an automatic document feeder (hereinafter referred to as a lower feed type ADF) in which the document tray is arranged below the discharge tray and an automatic document feeder in which the document tray is arranged above the discharge tray. When an image reading apparatus equipped with (hereinafter referred to as an upper feed type ADF) is mixed in the same workplace (floor), the user attempts to perform image reading using the automatic document feeder (ADF). The document to be read may be placed on the wrong tray.

  That is, in an environment in which the upper ADF and the lower ADF are mixed, the user places a document on the lower tray for each ADF (image reading device) to be used. It should be remembered whether the document should be placed on the upper tray.

  For this reason, there is a high possibility that the document to be read will be placed on the wrong tray, and of course, if the document is placed on the wrong tray, the document cannot be automatically read using the ADF. From the user's perspective, it is difficult to say that it is easy to use.

  SUMMARY An advantage of some aspects of the invention is that it improves the usability of an automatic document feeder and an image reading apparatus.

  In order to achieve the above object, the present invention provides an automatic document feeder that automatically conveys a document to a reading unit (103) that reads an image described in the document. A document tray (121) on which a document to be read is placed, a discharge tray (123) from which a document from which an image has been read are discharged, and an approximate U from the document tray (121) to the discharge tray (123) side. A discharge means (131) for discharging the document conveyed from the character-shaped transport path (Lo) to the discharge tray (123) side, and provided on the downstream side in the transport direction from the discharge means (131). The discharge means (131) Non-return means (1) that allows the document to flow in the forward direction from the discharge tray (123) to the discharge tray (123) and prohibits the document from flowing in the reverse direction from the discharge tray (123) to the discharge means (131). Characterized in that it comprises a 3) and.

  Thus, according to the first aspect of the present invention, since the check means (133) is provided even if the user erroneously inserts and places the document on the discharge tray (123), the user removes the document from the discharge tray. (123) cannot be inserted and mounted.

  Therefore, for example, even in an environment in which the ADF on the upper sheet feeding side and the ADF on the lower sheet feeding side are mixed, it is possible to prevent the user from placing the document to be read on the wrong tray. Usability of the document feeder can be improved.

  In the invention according to claim 2, the check means (133) includes a closed position for closing at least part of the downstream side in the transport direction from the discharge means (131) and a downstream position in the transport direction from the discharge means (131). When the closing member (133A) is configured to have a closing member (133A) that is displaceable between the opening position and the opening position, the closing member (133A) is subjected to a forward force acting on the closing member (133A). And the closing position when the force in the reverse direction acts on the closing member (133A).

  Thus, according to the second aspect of the present invention, when the document is inserted and placed on the discharge tray (123), the document comes into contact with the blocking member (133A), so that the blocking member (133A) is in the blocking position, and the document is moved forward. Since the closing member (133A) is brought into the open position by touching the closing member (133A) when being conveyed in the direction, the automatic document is prevented from being inserted and placed on the discharge tray (123). Usability of the transport device can be improved.

  In the invention according to claim 3, the closing member (133A) is disposed so as to be swingable by a swing shaft (133B) provided above the center of gravity of the closing member (133A). Further, the non-return means is a stopper (133C) that prohibits a portion of the closing member (133A) below the center of gravity from swinging from the closed position to the open position by contacting the closing member (133A). ), The check means can be configured with a simple structure.

  In the invention according to claim 4, the check means (133) is configured such that the direction of the moment around the swinging shaft (133B) generated by the gravity acting on the closing member (133A) is the stopper (133C). It is comprised so that it may become the direction which the contact surface pressure between a closure member (133A) increases.

  Thus, in the invention according to claim 4, when the closing member (133A) is in a free state, the closing member (133A) is caused by a moment around the swing shaft (133B) generated by gravity acting on the closing member (133A). Tries to maintain the closing position, so that the blocking member (133A) can be prevented from unnecessarily swinging.

  The invention according to claim 5 is characterized in that, when the closing member (133A) is located at the closing position, the position of the center of gravity of the closing member (133A) is shifted in the forward direction from the swing shaft (133B). And

Thereby, in the invention described in claim 5, the invention described in claim 4 can be realized with a simple configuration.
Further, the invention according to claim 6 is characterized in that the blocking member (133A) is provided only at a portion corresponding to the substantially central portion in the width direction of the document.

  Accordingly, in the invention described in claim 6, the function of the check means (133) that allows the document to flow in the forward direction and prohibits the document from flowing in the reverse direction is reliably exhibited. In addition, the flow resistance (conveyance resistance) generated when the closing member (133A) and the document come into contact with each other when the document is distributed (conveyed) in the forward direction can be reduced. It can be made smaller than the case where it is provided.

The “document width direction” means a direction orthogonal to the document distribution direction and the document thickness direction.
In the invention described in claim 7, the discharge tray (123) is provided with a convex portion (123B) protruding upward in the substantially central portion in the width direction, and the closing member (133A) is convex in the width direction. Further, the check means (133) is provided on both end sides shifted from the portion (123B). When the closing member (133A) is located at the closing position, the lower end portion of the closing member (133A) is convex. It is comprised so that it may be located below the upper end of a part (123B).

  Accordingly, in the invention described in claim 7, the function of the check means (133) can be surely exerted, and it is assumed that the bent portion (curl) that protrudes in the direction opposite to the convex portion (123B) is provided. ) Is placed on the document tray (121), it can be discharged to the discharge tray (123) while correcting the curl.

  By the way, in general, since there are many automatic document feeders in which the document tray is arranged above the discharge tray, the discharge tray (123) is located on the upper side of the document tray (121) as described in claim 8. It is particularly effective if the automatic document feeder according to any one of claims 1 to 7 is applied to the automatic document feeder provided in the above.

  According to the ninth aspect of the present invention, the dimension from the end on the forward direction side to the closing member (133A) located at the closing position among the ends of the discharge tray (123) is the outer dimension of the readable document. Is smaller than the outer dimension in the direction parallel to the forward direction.

  Thus, in the invention described in claim 9, even if the user mistakenly places the document on the discharge tray (123), the document does not fit in the discharge tray (123) and protrudes from the discharge tray (123). It is possible to prevent the user from erroneously placing the document to be read on the discharge tray (123).

  According to a tenth aspect of the present invention, there is provided an automatic document feeder according to any one of the first to ninth aspects, and a reading unit that reads an image written on a document conveyed by the automatic document feeder. It is characterized by providing.

  Incidentally, the reference numerals in parentheses for each of the above means are examples showing the correspondence with the specific means described in the embodiments described later, and the present invention is indicated by the reference numerals in the parentheses of the above respective means. It is not limited to specific means.

  In the present embodiment, an automatic conveyance reading function (ADF reading function) that reads an image described on a document while automatically conveying the document, and a stationary document reading function (ADF) that reads an image described on a stationary document ( An automatic document feeder according to the present invention is applied to an image reading apparatus (scanner) having a flatbed reading function. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1. FIG. 1 is an external perspective view of the image reading apparatus 100 according to the present embodiment as viewed from above, FIG. 2 is a sectional view showing the structure of an automatic document feeder mechanism 120, and FIG. FIG. 4 is an enlarged view of the periphery, and FIG.

2. Schematic configuration of image reading apparatus (see FIGS. 1 and 2)
As shown in FIG. 2, the main body 101 of the image reading apparatus 100 according to the present embodiment includes an image reading window (hereinafter referred to as a stationary reading window) 102 for a stationary document reading function and an automatic conveyance reading function. An image reading window (hereinafter referred to as an automatic reading window) 103 is provided, and both the reading windows 102 and 103 are closed by transparent platens 102A and 103A such as glass and acrylic.

  Further, a document cover 104 (see FIG. 1) that covers both the reading windows 102 and 103 is swingably assembled on the upper surface side of the main body 101, and when reading a document through the stationary reading window 102. Then, the document cover 104 is opened upward by manual operation, and the document is placed on the stationary reading window 102.

  On the other hand, in the main body 101, there is disposed an image pickup device 105 that receives light reflected from the original and reflects the received light, and generates an electrical signal based on the received light. An image such as characters written on a document is converted into an electrical signal via the image sensor 105 to read the image.

  Incidentally, in the present embodiment, a CIS (Contact Image Sensor) is used as the image pickup device 105, and the longitudinal direction of the CIS (image pickup device 105) is directly below the reading windows 102 and 103, and the moving direction thereof. It extends in a direction orthogonal to the direction (direction perpendicular to the paper surface).

  The image pickup device 105 is assembled to the main body 101 so as to be movable in the longitudinal direction of the main body 101 (the left-right direction in FIG. 2). The image is read in a state where it is stopped and placed immediately below the image sensor. On the other hand, when the stationary document reading function is activated, the image pickup device 105 reads the image while moving immediately below the stationary reading window 102.

  Further, an automatic document transport mechanism (auto document feeder (ADF)) 120 that transports a document for reading to the automatic reading window 103 is provided in a portion corresponding to the automatic reading window 103 in the vicinity of the document cover 104. Yes. The automatic document conveyance mechanism 120 is an automatic document conveyance device to which the present invention is applied.

2. Configuration of automatic document feeder (see Fig. 2)
The document tray 121 is for placing a document to be read, and a discharge tray 123 for placing a document for which image reading has been completed is provided above the document tray 121. Incidentally, a plurality of documents are placed on the document tray 121 or the discharge tray 123 in a state where the thickness direction is stacked vertically.

  The document tray 121 and the discharge tray 123 are displaced in the horizontal direction from the portion corresponding to the automatic reading window 103 in the automatic document transport mechanism 120 (hereinafter, this portion is referred to as a mechanism main body 120A) (in FIG. 2). , A position shifted to the right).

  Further, on the mechanism main body 120 </ b> A side of the document tray 121, a feeder mechanism 125 that conveys the document to the automatic reading window 103 in order from the document located at the bottom of the plurality of documents placed on the document tray 121. Is provided.

  The feeder mechanism 125 separates a plurality of documents conveyed from the document tray 121 and sends them one by one, and is provided on the upstream side in the conveyance direction from the separation unit 127 and is placed on the document tray 121. And a suction unit 129 that draws in the document and sends it to the separation unit 127.

  The separation unit 127 rotates in contact with the lower surface side of the document to apply a separation roller 127A that applies a conveyance force to the document, and a displacement that contacts the document from the side opposite to the separation roller 127A and applies a conveyance resistance to the document. It includes a possible separation pad 127B, and a spring 127C that generates an elastic force that presses the separation pad 127B toward the separation roller 127A.

  Further, the suction unit 129 presses the suction roller 129A that applies a conveying force to the document by rotating in contact with the document, the displaceable nip piece 129B that presses the document against the suction roller 129A, and the nip piece 129B toward the suction roller 125A. A spring 129C or the like that generates an elastic force is included.

  For this reason, a plurality of documents drawn from the document tray 121 are separated into about several sheets by the suction unit 129 and sent to the separation unit 127, and then the separation roller 127A among the several separated documents is sent. Is brought out of the separation unit 127.

  At this time, the document located on the separation pad 127B side from the document that contacts the separation roller 127A stops without being carried out due to the conveyance resistance from the separation pad 127B, and therefore, a plurality of documents placed on the document tray 121. Are conveyed one by one from the document placed at the bottom to the automatic reading window 103.

  Further, the first transport roller 130 provided on the downstream side in the transport direction from the separation unit 127 rotates in contact with the document on the lower end side thereof, whereby the document transported by the separation roller 127 </ b> A is input to the automatic reading window 103. On the other hand, the document that has passed through the automatic reading window 103 is conveyed to the discharge roller 131 side by rotating in contact with the document at its upper end.

  The sheet discharge roller 131 is a discharge unit that discharges the document conveyed via the substantially U-shaped conveyance path Lo from the document tray 121 to the discharge tray 123 side, and the pinch roller 131A. A pressure roller that presses the document against the paper discharge roller 131.

  Note that the pinch rollers 130A and 130B are pressure rollers that press the document against the first conveying roller 130, and these pinch rollers 130A, 130B, and 131A rotate in contact with the conveyed document.

  The document is allowed to flow in the forward direction from the paper discharge roller 131 to the discharge tray 123 (in the direction of the black arrow in FIG. 2) downstream of the paper discharge roller 131 in the transport direction, and the discharge tray. A check mechanism 133 is provided that prohibits the document from flowing in the reverse direction from 123 to the paper discharge roller 131 (the direction of the arrow indicated by the broken line in FIG. 2).

  The check mechanism 133 closes the downstream side in the transport direction (hereinafter referred to as a document discharge port 123A) from the discharge roller 131 and an open position that opens the document discharge port 123A. A check cover 133 </ b> A that can swing and displace between the two-dot chain line or the broken line in FIG. 2 is configured.

  As shown in FIG. 1, the check cover 133 </ b> A is provided only in a portion of the document discharge port 123 </ b> A corresponding to a substantially central portion in the width direction of the document, and in the forward direction with respect to the check cover 133 </ b> A. It is configured to be in an open position (two-dot chain line in FIG. 2) when a force is applied, and in a closed position when a reverse force is applied to the check cover 133A. The “document width direction” refers to a direction orthogonal to the document transport direction and the document thickness direction.

  That is, as shown in FIG. 2, the check cover 133 </ b> A is disposed so as to be swingable by a swing shaft 133 </ b> B provided at an upper end located above the gravity center position G of the check cover 133 </ b> A. In this case, the check cover 133A swings from the closed position to the paper discharge roller 131 side by contacting the lower end side of the check cover 133A from the paper discharge roller 131 side (a state indicated by a broken line in FIG. 2). A stopper 133 </ b> C that prohibits the rocking displacement to the side is provided.

  Further, the check mechanism 133 is configured such that the center of gravity position G of the check cover 133A is located at a position shifted in the forward direction from the swing shaft 133B when the check cover 133A is located at the closed position. . For this reason, a force in a direction in which the contact surface pressure with the stopper 133 </ b> C increases is always applied to the check cover 133 </ b> A due to the moment around the swing shaft 133 </ b> B generated due to gravity acting on the check cover 133 </ b> A.

  A dimension L1 (see FIG. 1) from the end of the discharge tray 123 to the check cover 133A located at the closing position is parallel to the forward direction of the readable document. The dimension is set to be smaller than the outer dimension in a proper direction.

  The “outside dimension of the readable document in the direction parallel to the forward direction” is, for example, when the document is conveyed such that the long side direction of the A4 size document matches the forward direction. Means the dimension in the long side direction.

  A second transport roller 132 that transports the document that has passed through the automatic reading window 103 toward the discharge tray 123 is provided at a position downstream of the automatic reading window 103 in the transport direction and shifted from the platen 103A. The original to which the conveying force is applied from the second conveying roller 132 is turned by the guide member to the upper side by approximately 180 ° and then discharged to the discharge tray 123 side.

The pinch roller 132A is a pressure roller that presses the document against the second transport roller 132, and the pinch roller 132A contacts the transported document and rotates in a driven manner.
Further, on the discharge roller 131 side of the discharge tray 123, a protrusion for allowing the document discharged from the discharge roller 131 to enter between the document already placed on the discharge tray 123 and the discharge tray 123. 134 is provided.

  As shown in FIG. 3, the protrusion 134 is a portion lifted by the protrusion 134 (FIG. 3) by lifting the discharge roller 131 side of the document placed on the discharge tray 123 from the discharge tray 123. Of the document ejected from the sheet ejection roller 131.

  In other words, the original discharged from the paper discharge roller 131 is the lower surface side of the original placed on the discharge tray 123 and located on the lower side of the original on the paper discharge roller 131 side than the protrusion 134. Since the conveying direction is turned to the horizontal portion 134A after an acute collision with (A portion in FIG. 3), the document discharged from the discharge roller 131 is the document already placed on the discharge tray 123. And the discharge tray 123 are placed on the discharge tray 123 so as to be submerged.

3. When the reading start button (not shown) is pressed by the user with the document reading surface side down and a plurality of documents placed on the document tray 121, A conveyance motor (not shown) rotates, and the plurality of documents stacked on the document tray 121 are sequentially transported from the document positioned at the bottom in the stacking direction to the automatic reading window 103 and image reading is started.

  As a result, the document whose image reading has been completed is discharged from the discharge roller 131 to the discharge tray 123 via the conveyance path Lo as indicated by a thick arrow in FIG. Then, the document is placed on the document tray 121 so as to enter the lowest position in the stacking direction of the documents already placed on the discharge tray 123.

  Therefore, since the originals that have been read are stacked from top to bottom in the order in which the image reading has been completed so that the reading side of the original is the top surface, in this embodiment, the originals are placed on the original tray 121. A plurality of stacked originals are placed on the discharge tray 123 in an inverted state.

4). Features of Image Reading Device (Automatic Document Feed Mechanism) According to this Embodiment In this embodiment, the document is allowed to flow in the forward direction from the discharge roller 131 to the discharge tray 123 and is discharged from the discharge tray 123. Since a check mechanism 133 that prohibits the document from flowing in the reverse direction toward the paper roller 131 is provided in the document discharge port 123A, even if the user mistakenly inserts and places the document on the discharge tray 123, the check is not performed. The mechanism 133 prevents the user from inserting and placing the document on the discharge tray 123.

  Therefore, for example, even in an environment in which the ADF on the upper sheet feeding side and the ADF on the lower sheet feeding side are mixed, it is possible to prevent the user from placing the document to be read on the wrong tray. Usability of the document feeder can be improved.

  In this embodiment, the check cover 133A is in the open position when a forward force is applied to the check cover 133A, and a reverse force is applied to the check cover 133A. Therefore, when the document is inserted and placed on the discharge tray 123, when the document touches the check cover 133A, the check cover 133A becomes the closed position, and the document is conveyed in the forward direction. When the check cover 133A is touched, the check cover 133A is in the open position. Therefore, the usability of the automatic document feeder can be improved while preventing the document from being inserted and placed on the discharge tray 123.

  Further, in this embodiment, the check cover 133A is disposed so as to be swingable by the swing shaft 133B provided above the center of gravity G of the check cover 133A. The stopping mechanism 133 can be configured.

  In the present embodiment, the check cover 133A is always subjected to a force that increases the contact surface pressure between the stopper 133C and the check cover 133A. Therefore, when the check cover 133A is in a free state. Since the check cover 133A tries to maintain the closed position, the check cover 133A can be prevented from unnecessarily swinging.

  In the present embodiment, the check cover 133A is provided only in a portion corresponding to the substantially central portion in the width direction of the document, so that the document can be circulated in the forward direction and the document can be reversed. The function of the check mechanism 133 that prohibits the circulation of the document can be reliably exerted, and the check cover 133A and the document come into contact with each other when the document is distributed (conveyed) in the forward direction. The distribution resistance (conveyance resistance) can be made smaller than when the check cover 133A is provided in the entire width direction.

  In the present embodiment, the dimension L1 from the end on the forward direction side of the end of the discharge tray 123 to the check cover 133A located at the closing position is parallel to the forward direction among the outer dimensions of the readable document. Therefore, even if the user mistakenly places the document on the discharge tray 123, the document does not fit on the discharge tray 123 and protrudes from the discharge tray 123. Therefore, it is possible to prevent the user from placing the document to be read on the discharge tray 123 by mistake.

5). Correspondence Relationship between Invention Specific Items and Embodiment In this embodiment, the discharge roller 131 corresponds to the discharge means described in the claims, and the check mechanism 133 is the check means described in the claims. The check cover 133A corresponds to the closing member described in the claims.

(Second Embodiment)
In the present embodiment, as shown in FIG. 5, the discharge tray 123 is arranged below the document tray 121.

  When the discharge tray 123 is disposed below the document tray 121, the document discharged from the discharge roller 131 is inserted between the document already placed on the discharge tray 123 and the discharge tray 123. There is no need to place it on the discharge tray 123.

(Third embodiment)
In the present embodiment, as shown in FIG. 6, a convex portion 123 </ b> B protruding upward is provided at a substantially central portion in the width direction of the discharge tray 123, and a check cover 133 </ b> A is provided at both end sides shifted from the convex portion 123 </ b> B in the width direction. When the check cover 133A is positioned at the closed position, the lower end of the check cover 133A is positioned below the upper end of the convex portion 123B (the imaginary line L2 in FIG. 2). Is.

  As a result, in the present embodiment, the function of the check mechanism 133 can be surely exerted, and a document having a curl that is convex in the direction opposite to the convex portion 123B is temporarily document tray 121. Can be discharged to the discharge tray 123 while correcting the bent wrinkles.

In addition, although the convex part 123B shown in FIG. 6 is comprised by the protrusion extended in a discharge direction, this embodiment is not limited to this.
FIG. 6 shows an example in which the present embodiment is applied to the second embodiment, but the present invention is not limited to this, and the present embodiment may be applied to the first embodiment.

(Other embodiments)
In the above-described embodiment, the swing shaft 133B is provided at the upper end of the check cover 133A. However, the present invention is not limited to this. For example, the swing shaft 133B is connected to the upper end of the check cover 133A. The lower side may be higher than the center of gravity G of the check cover 133A.

  In such a configuration, a portion of the check cover 133A on the lower side of the center of gravity position is prohibited from swinging from the closed position to the open position by the stopper 133C.

  In the above-described embodiment, the force in the direction in which the contact surface pressure between the stopper 133C and the check cover 133A increases always acts on the check cover 133A using the moment due to gravity acting on the check cover 133A. Although the present invention is configured, the present invention is not limited to this. For example, by using elastic means such as a torsion spring, the force in the direction in which the contact surface pressure between the stopper 133C and the check cover 133A increases is always reversed. It is good also as a structure which acts on the stop cover 133A.

  In the above-described embodiment, the check cover 133A is displaced between the closed position and the open position by causing the document to directly collide with the check cover 133A. However, the present invention is limited to this. The check cover 133A may be displaced using an actuator that is mechanically or electrically displaced according to the presence or absence of a document.

  In the above-described embodiment, the check cover 133A is provided in a part of the document discharge port 123A in the width direction. However, the present invention is not limited to this, and the check cover 133A is provided in the entire width direction. It may be provided.

  In the above-described embodiment, the document tray 121 and the discharge tray 123 are arranged so as to be shifted in the vertical direction. However, the present invention is not limited to this. For example, the document tray 121 and the discharge tray 123 are arranged in the horizontal direction. The present invention can also be applied to an automatic document feeder arranged in a shifted manner.

  Further, in the above-described embodiment, the check cover 133A is oscillating and displaced, but the present invention is not limited to this, and for example, it may be displaced vertically or horizontally. .

  In the above-described embodiment, the check cover 133A closes the document discharge port 123A over substantially the entire thickness direction (vertical direction in FIG. 2) of the document, but the present invention is not limited to this. It may not be a thing, but the part may be obstruct | occluded.

Further, the check cover 133A may be used as a sensor actuator of a discharge sensor that detects whether or not a document is discharged.
In the above-described embodiment, the stopper 133C and the check cover 133A come into contact with each other in order to realize a configuration in which the center of gravity position G of the check cover 133A is located at a position shifted in the forward direction from the swing shaft 133B. The part is configured to be located at a part deviated in the forward direction from the vertical line passing through the swing shaft 133B. This is because the check cover 133A has a simple plate shape.

  Therefore, for example, when the center of gravity of the check cover 133A is located closer to the discharge tray 123 than the plate surface of the check cover 133A, the portion where the stopper 133C and the check cover 133A come into contact passes through the swing shaft 133B. It may be positioned on the vertical line.

In the above-described embodiment, the present invention is applied to a single-sided reading type image reading apparatus. However, the present invention is not limited to this and can also be applied to an image reading apparatus capable of double-sided reading.
Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

1 is an external perspective view of an image reading apparatus 100 according to a first embodiment of the present invention as viewed from the upper surface side. FIG. 2 is a cross-sectional view showing a structure of an automatic document feeder mechanism 120 according to an embodiment of the present invention. FIG. 4 is an enlarged view around a protrusion 134 of an automatic document feeder mechanism 120 according to an embodiment of the present invention. FIG. 6 is a diagram illustrating a document conveyance state. It is the external appearance perspective view which looked at the image reading apparatus 100 which concerns on 2nd Embodiment of this invention from the upper surface side. It is the external appearance perspective view which looked at the image reading apparatus 100 which concerns on 3rd Embodiment of this invention from the upper surface side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Image reading apparatus, 101 ... Main-body part, 102 ... Static reading window,
102A ... platen, 103 ... automatic reading window, 103A ... platen,
104: Document cover, 105: Image pickup device, 120: Automatic document transport mechanism,
120A ... mechanism main body, 121 ... document tray, 123 ... discharge tray,
123A: Document discharge port, 123B: Projection, 125: Feeder mechanism,
127: Separation unit, 127A ... Separation roller, 127B ... Separation pad, 129 ... Suction unit,
129A ... Suction roller, 129B ... Nip piece, 130 ... First transport roller,
130A ... Pinch roller, 131 ... Discharge roller, 131A ... Pinch roller,
132: second conveying roller, 132A: pinch roller, 133: check mechanism,
133A ... Check cover, 133B ... Oscillating shaft, 133C ... Stopper, 134 ... Projection.

Claims (10)

An automatic document feeder that automatically conveys a document to a reading unit that reads an image written on the document,
A document tray on which documents to be read are placed;
A discharge tray for discharging the document whose image has been read;
A discharge means for discharging the document conveyed from a substantially U-shaped conveyance path from the document tray to the discharge tray side to the discharge tray side;
Provided on the downstream side in the transport direction from the discharge unit, allows the document to flow in the forward direction from the discharge unit to the discharge tray, and flows in the reverse direction from the discharge tray to the discharge unit. An automatic document feeder comprising: check means for prohibiting to perform. The check means includes a closing member that is displaceable between a closing position that closes at least a part of the downstream side in the transport direction from the discharge means and an open position that opens the downstream side in the transport direction from the discharge means. Configured,
Furthermore, the closing member is in the open position when the forward force is applied to the closing member, and the closing position is applied when the reverse force is applied to the closing member. The automatic document feeder according to claim 1, wherein the automatic document feeder is configured as follows. The closing member is disposed so as to be swingable by a swing shaft provided above the center of gravity of the closing member,
Further, the non-return means has a stopper that prohibits a portion of the closing member below the center of gravity from swinging from the closed position to the open position by contacting the closing member. An automatic document feeder characterized by the above.   The non-return means is configured such that the direction of the moment around the swing axis generated with gravity acting on the closing member is such that the contact surface pressure between the stopper and the closing member increases. The automatic document feeder according to claim 3, wherein the automatic document feeder is configured.   5. The automatic document feeder according to claim 4, wherein when the closing member is located at the closing position, the position of the center of gravity of the closing member is shifted in the forward direction from the swing shaft.   6. The automatic document feeder according to claim 2, wherein the closing member is provided only at a portion corresponding to a substantially central portion in the width direction of the document. A convex portion that protrudes upward is provided at a substantially central portion in the width direction of the discharge tray.
The closing member is provided on both end sides shifted from the convex portion in the width direction,
Further, the check means is configured such that, when the closing member is located at the closing position, the lower end portion of the closing member is positioned below the upper end of the convex portion. An automatic document feeder according to any one of claims 2 to 5.   The automatic document feeder according to claim 2, wherein the discharge tray is provided above the document tray. Automatic document feeder.   The dimension from the end on the forward direction side to the closing member located at the closing position among the ends of the discharge tray is based on the outer dimensions of the readable document in the direction parallel to the forward direction. 9. The automatic document feeder according to claim 8, wherein the automatic document feeder is small. An automatic document feeder according to any one of claims 1 to 9,
An image reading apparatus comprising: a reading unit configured to read an image described on a document conveyed by the automatic document conveying device.

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