JP7172087B2 - Media transport device - Google Patents

Description

The present invention relates to a medium conveying device that conveys a medium such as a document.

Conventionally, there has been provided an image reading apparatus that reads an image of a document by an ADF (Auto Document Feeder) method. In the ADF method, for example, documents stacked on a tray are sandwiched between a separation roller and a pinch roller. While the document is being conveyed, the image of the document is read by a CIS (Contact Image Sensor) unit.

A pair of left and right document guides extending in the transport direction is provided on the tray to prevent so-called skew, in which the document is transported with the edge in the transport direction inclined with respect to the transport direction. It is As a result, while the trailing edge of the document remains on the tray, the left and right ends of the document are guided by the document guides, respectively, thereby preventing the document from skewing. However, if the length of the document in the transport direction is short, the trailing edge of the document may come off the document guide before the leading edge of the document reaches the transport roller downstream of the separation roller, and the document may be transported only by the separation roller and the pinch roller. may be In this state, the document may be skewed due to the difference in nip pressure between the separation roller and the pinch roller.

In order to correct the skew, for example, a technique has been proposed in which the document is abutted against a stationary roller to correct the skew when the document is skewed (see, for example, Patent Document 1). . Further, a technique has been proposed in which a separation roller is divided into left and right parts, and skew feeding is corrected by changing the amount of rotation of the left and right separation rollers (see, for example, Japanese Unexamined Patent Application Publication No. 2002-100002).

JP-A-2005-187113 Japanese Patent No. 5814166

However, the technology proposed by the former requires relatively expensive parts such as an electromagnetic clutch for fixing the rollers in a stopped state. On the other hand, the technique proposed by the latter requires a configuration for changing the amount of rotation of the left and right separation rollers, and moreover, when a document is skewed, the skew is corrected from the next document.

SUMMARY OF THE INVENTION An object of the present invention is to provide a medium conveying device capable of correcting skew of a medium such as a document with an inexpensive configuration.

In order to achieve the above object, a medium conveying apparatus according to the present invention includes a separation roller for separating and conveying a medium one by one, and a medium conveying apparatus disposed downstream of the separation roller in a medium conveying direction. and a correction mechanism disposed between the separating roller and the conveying roller, wherein the correcting mechanism rotates around an axis extending in a width direction orthogonal to the conveying direction. A one-side swinging member provided swingably and having a first protrusion and a second protrusion, and a third protrusion and a fourth protrusion provided swingably around an axis extending in the width direction. a first blocking position for blocking the movement of the third protrusion and the movement of the third protrusion accompanying movement of the second protrusion due to the swinging of the one-side swing member; A first stopper provided movably between a first permissible position that permits a second stopper movably provided between a second blocking position that blocks movement and a second allowable position that permits movement of the first projection; 1 blocking position, the second stopper is located at the second blocking position, and the one-side rocking member rocks due to contact with the medium. When the stopper moves from the first blocking position to the first allowing position, and the second side swinging member swings due to contact with the medium, the fourth protrusion moves. 2 moving from the blocking position to the second allowing position;

According to this configuration, when the medium is skewed so that one side in the width direction of the medium conveyed by the separation roller is ahead of the other side, the medium swings on one side before contacting the swinging member on the other side. come into contact with the material. At this time, since the second stopper is positioned at the second blocking position, even if the medium comes into contact with the one-side swinging member, the movement of the first protrusion of the one-side swinging member is prevented, and the one-side swinging member is prevented from moving. The moving member does not swing. Thereafter, when a conveying force is applied from the separation roller to the medium, the conveying force causes the medium to swing with the point of contact with the one-side swinging member as a fulcrum so that the other side catches up with the one side. When the medium comes into contact with the other-side swinging member, the other-side swinging member swings, and the second stopper moves from the second blocking position to the second position as the fourth protrusion of the other-side swinging member moves due to the swinging motion. 2 Move towards the permissible position. As a result, the movement of the first protrusion of the one-side swinging member is permitted, the one-side swinging member also swings, and the medium is moved to the one-side swinging member and the other side in a state in which the oblique feeding of the medium is corrected. Go beyond the rocking member.

Conversely, when the medium is skewed such that the other side in the width direction of the medium conveyed by the separation roller is ahead of the one side, the other side swings before the medium contacts the one side swing member. come into contact with the material. At this time, since the first stopper is positioned at the first blocking position, even if the medium comes into contact with the other-side swinging member, the movement of the third protrusion of the other-side swinging member is prevented and the other-side swinging member is prevented from moving. The moving member does not swing. Thereafter, when a conveying force is applied from the separation roller to the medium, the conveying force swings the medium so that one side catches up with the other side with the point of contact with the other-side swinging member as a fulcrum. When the medium contacts the one-side swinging member, the one-side swinging member swings, and the first stopper moves from the first blocking position to the second position as the second protrusion of the one-side swinging member moves due to the swinging motion. 1 Move towards the permissible position. As a result, the movement of the third protrusion of the other-side swinging member is permitted, the other-side swinging member also swings, and the medium is moved to the one-side swinging member and the other side in a state in which the oblique feeding of the medium is corrected. Go beyond the rocking member.

Therefore, the skew of the medium can be corrected with an inexpensive configuration.

According to the present invention, skew feeding of a medium such as a document can be corrected with an inexpensive configuration.

1 is a cross-sectional view of an image reading device to which a medium conveying device according to an embodiment of the invention is applied; FIG. 4 is a perspective view of a skew correction mechanism; FIG. 4 is a perspective view showing the skew correction mechanism with the first stopper omitted; FIG. It is a perspective view of a 1st stopper. It is a perspective view of a 2nd stopper. FIG. 4 is a side view of the skew correction mechanism, showing a state before the original comes into contact with the first swing gate and the second swing gate; FIG. 4 is a cross-sectional view of the skew correction mechanism, showing a state before the original comes into contact with the first swing gate and the second swing gate; FIG. 11 is a side view of the skew correction mechanism, showing a state where the second gate bar of the second rocking gate is tilted; FIG. 10 is a cross-sectional view of the skew correction mechanism, showing a state in which the second gate bar of the second swing gate is tilted; FIG. 4 is a side view of the skew correction mechanism, showing a state in which the first rocking gate and the second rocking gate are tilted; FIG. 4 is a cross-sectional view of the skew correction mechanism, showing a state in which the first rocking gate and the second rocking gate are tilted; FIG. 11 is a schematic side view of a skew correction mechanism according to another embodiment of the present invention, showing the configuration on the side of a first swing gate; FIG. 13 is a schematic side view of the skew correction mechanism shown in FIG. 12, showing the configuration on the second swing gate side;

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Configuration of image reading device>
An image reading device 1 (an example of a medium conveying device) shown in FIG. 1 is an electronic device that reads an image of a document by an ADF (Auto Document Feeder) method. The image reading device 1 has a housing 2 , a supply tray 3 and a discharge tray 4 . The supply tray 3 is provided on one side of the housing 2 , and the discharge tray 4 is provided on the opposite side of the housing 2 to the supply tray 3 . In the image reading apparatus 1, one side of the housing 2 where the supply tray 3 is provided is the rear side, and the opposite side is the front side. The supply tray 3 extends rearward and upward from the housing 2 in use. The discharge tray 4 extends forward from the housing 2 in use.

For use in the following description, left and right are defined based on a state in which the image reading apparatus 1 is viewed from the front side.

The housing 2 is formed with a support surface 11 extending forward and downward from the vicinity of the front end of the supply tray 3 in use. The front end of the support surface 11 forms the lower end of an insertion port 12 that communicates the inside and outside of the housing 2 . Further, the housing 2 is formed with a discharge port 13 that communicates the inside and outside of the housing 2 at a position above the rear end portion of the discharge tray 4 .

A conveying path 14 is provided in the housing 2 and extends from the insertion port 12 toward the discharge port 13 while being inclined forward and downward. A separation roller 15 , a separation piece 16 , a conveyance roller 17 , and a discharge roller 18 are provided in order from the insertion port 12 side along the conveyance path 14 inside the housing 2 . The separation roller 15 is arranged so that its peripheral surface is in contact from below with an imaginary plane extending forward along the support surface 11 . The separation piece 16 is arranged so as to abut on the peripheral surface of the separation roller 15 from the front upper side. The conveying roller 17 is arranged at a position separated from the separation roller 15 . The conveying rollers 17 are composed of a pair of upper conveying rollers 21 and lower conveying rollers 22 . The upper conveying roller 21 and the lower conveying roller 22 form a nip when their peripheral surfaces come into contact with each other on the conveying path 14 . The discharge rollers 18 consist of a pair of upper discharge rollers 23 and lower discharge rollers 24 . The upper discharge roller 23 and the lower discharge roller 24 form a nip by contacting their peripheral surfaces on the conveying path 14 , and the nip portion is exposed to the outside of the housing 2 from the discharge port 13 .

A first CIS (Contact Image Sensor) 25 and a second CIS 26 are provided between the transport roller 17 and the discharge roller 18 . The first CIS 25 is arranged below the transport path 14 . The second CIS 26 is arranged above the conveying path 14 and at a position shifted forward with respect to the first CIS 25 . The first CIS 25 and the second CIS 26 include an image sensor in which a plurality of light receiving elements are arranged in the width direction of the document being conveyed, a light source that irradiates light toward the conveying path 14, and light emitted from the light source and reflected by the object to be irradiated. and a rod lens array for forming an image of the received light on each light receiving element of the image sensor. The image sensor outputs an analog signal corresponding to the light received by each light receiving element.

When executing a scan job for reading an image of a document, for example, the document is gripped by a user's fingers, and the front end of the document slides on the support surface 11 of the housing 2 and is inserted into the housing 2 from the insertion opening 12 . inserted into the After the document is inserted into the housing 2 until the leading edge of the document contacts the peripheral surface of the separation roller 15 , the document is supported by the supply tray 3 and the support surface 11 when the user's fingers are removed from the document. When the number of originals is plural, the plural originals are stacked and supported by the supply tray 3 and the support surface 11 . Depending on the size of the document, the document is supported only by the support surface 11 without reaching over the supply tray 3 .

Rotation of the separation roller 15, the conveying roller 17, and the discharge roller 18 is started in response to the user's instruction to start scanning. As the separation roller 15 rotates, a conveying force is applied from the separation roller 15 to the document in contact with the separation roller 15 , and the leading edge of the document passes between the separation roller 15 and the separation piece 16 . When a plurality of documents are stacked, the lowest document is separated from the other documents by passing between the separation roller 15 and the separation piece 16 . After that, when the document reaches the transport roller 17 , a transport force is applied to the document from the transport roller 17 , and the document is further transported toward the discharge roller 18 . When the document passes between the first CIS 25 and the second CIS 26 , light is emitted from the first CIS 25 to the lower surface of the document, and the image of the lower surface of the document is read by the first CIS 25 . When images on both sides of the document are to be read, light is emitted from the second CIS 26 to the upper surface of the document, and the image on the upper surface of the document is read by the second CIS 26 . When the document reaches the discharge roller 18 , a conveying force is applied to the document from the discharge roller 18 , and the document is discharged onto the discharge tray 4 by the conveying force.

<Skew Correction Mechanism>
The image reading apparatus 1 includes a skew correction mechanism 31 (correction mechanism) to prevent a document from being conveyed with its edge in the conveying direction inclined with respect to the conveying direction, that is, a so-called skew. example) is provided. As shown in FIG. 2, the skew correction mechanism 31 includes a first rocking gate 32 (an example of one side rocking member), a second rocking gate 33 (an example of the other side rocking member), a first A stop 34 and a second stop 35 are included.

The first swing gate 32 integrally has a first gate shaft 41 , a first gate bar 42 , a first protrusion 43 and a second protrusion 44 . The first gate shaft 41 extends in the left-right direction and is swingably held by the housing 2 (see FIG. 1). The elastic force of the torsion coil spring 45 urges the first gate shaft 41 clockwise when viewed from the right side. The first gate bar 42 has a prism shape and extends in the radial direction of the first gate shaft 41 from the right end of the first gate shaft 41 . As shown in FIG. 1, the first gate bar 42 protrudes into the transport path 14 from below the transport path 14 in a state in which the first gate bar 42 is not in contact with another member (original document). In FIG. 1, the first gate bar 42 extends from the lower side of the transport path 14 to the upper front side. Define the front, back, top and bottom as As shown in FIG. 3, the first protrusion 43 and the second protrusion 44 are bifurcated from the left end of the first gate shaft 41 and protrude leftward. A thin plate-like contact portion 46 extending in the front-rear direction is formed at the tip of the first protrusion 43 . The second protrusion 44 is formed in a substantially quadrangular prism shape.

The first swing gate 32 and the second swing gate 33 are members having the same configuration, and the first swing gate 32 is moved along the axis of the first gate shaft 41 from the left end of the first gate shaft 41 by a predetermined distance. A 180° rotation about a straight line extending up and down through the separated points results in the configuration of the second swing gate 33 .

The second swing gate 33 integrally has a second gate shaft 51 , a second gate bar 52 , a third protrusion 53 and a fourth protrusion 54 . The second gate shaft 51 is arranged on the same axis as the first gate shaft 41, extends in the left-right direction, and is swingably held by the housing 2 (see FIG. 1). The elastic force of the torsion coil spring 55 urges the second gate shaft 51 clockwise when viewed from the right side. The second gate bar 52 has a prismatic shape and extends in the radial direction of the second gate shaft 51 from the right end portion of the second gate shaft 51 . As shown in FIG. 1, the second gate bar 52 protrudes into the conveying path 14 from below the conveying path 14 in a state in which the second gate bar 52 is not in contact with other members. As shown in FIG. 3, the third protrusion 53 and the fourth protrusion 54 are bifurcated from the right end of the second gate shaft 51 and protrude to the right. A thin plate-shaped contact portion 56 extending in the front-rear direction is formed at the tip of the third protrusion 53 . The fourth projecting portion 54 is formed in a substantially quadrangular prism shape.

The first stopper 34 is arranged between the second protrusion 44 of the first swing gate 32 and the third protrusion 53 of the second swing gate 33, as shown in FIG. As shown in FIG. 4, the first stopper 34 is generally in the shape of a quadrangular prism. A first swing shaft 61 is formed at the upper end of the first stopper 34 . The first swing shaft 61 protrudes leftward and rightward from its left side and right side, respectively. The right side surface of the first stopper 34 is formed with a first cam surface 62 convexly curved upward by cutting out in a substantially fan shape between the rear lower end and the substantially center of the front end. Furthermore, a first hook 63 is formed on the front surface of the first stopper 34 . As shown in FIG. 2 , one end of a first elastic body 64 made of a tension spring is engaged with the first hook 63 , and the first stopper 34 is pulled from the right side by the tensile force of the first elastic body 64 . It is biased in a clockwise direction as viewed.

The second stopper 35 is arranged between the first protrusion 43 of the first swing gate 32 and the fourth protrusion 54 of the second swing gate 33 . As shown in FIG. 5, the second stopper 35 is generally in the shape of a quadrangular prism. A second swing shaft 71 is formed at the lower end of the second stopper 35 . The second swing shaft 71 protrudes leftward and rightward from its left side and right side, respectively. The left side surface of the second stopper 35 is formed with a second cam surface 72 that is convexly curved downward by cutting out in a substantially sectoral shape between the front upper end and the substantially center of the rear end thereof. . Furthermore, a second hook 73 is formed on the rear surface of the second stopper 35 . As shown in FIG. 2, one end of a second elastic body 74 made of a tension spring is engaged with the second hook 73, and the second stopper 35 is pulled from the right side by the tensile force of the second elastic body 74. It is biased in a counterclockwise direction as viewed.

<Skew correction operation>
When the first gate bar 42 of the first rocking gate 32 and the second gate bar 52 of the second rocking gate 33 are not in contact with other members, the first gate bar 42 and the second gate bar 52 protrude into the transport path 14 . there is Therefore, the document conveyed on the conveying path 14 contacts the first gate bar 42 and the second gate bar 52 when passing through the positions where the first gate bar 42 and the second gate bar 52 are arranged.

Before the document contacts the first gate bar 42 and the second gate bar 52, as shown in FIGS. 6 and 7, the first stopper 34 is positioned at the first blocking position and the second stopper 35 is positioned at the second blocking position. located in In this state, the first gate bar 42 and the second gate bar 52 are arranged along the width direction perpendicular to the document transport direction, that is, along the left-right direction. Also, in this state, the contact portion 56 of the third protrusion 53 of the second swing gate 33 faces the lower surface of the first stopper 34 with a gap therebetween. Also, the fourth protrusion 54 is positioned near the upper end of the second cam surface 72 of the second stopper 35 and does not apply force to the second cam surface 72 . Regarding the first swing gate 32, although not shown, the contact portion 46 of the first protrusion 43 faces the upper surface of the second stopper 35 with a gap therebetween, and the second protrusion 44 It is positioned near the lower end of the first cam surface 62 of the first stopper 34 and no force is applied to the first cam surface 62 .

First, consider the case where the document is skewed with the left edge leading the right edge. When the document advances obliquely, the leading edge of the document contacts the second gate bar 52 before contacting the first gate bar 42 . As the document is conveyed, the document presses the second gate bar 52, and as shown in FIGS. It swings around the gate shaft 51 as a fulcrum. Due to this swinging, the contact portion 56 of the third projection 53 of the second swing gate 33 contacts the lower surface of the first stopper 34, and further swinging of the second swing gate 33 is prevented. The first stopper 34 is arranged such that a straight line orthogonal to the lower surface of the first stopper 34 at the contact portion of the contact portion 56 passes slightly forward of the center of the first swing shaft 61 . Therefore, even if the contact portion 56 abuts against the lower surface of the first stopper 34 , the first stopper 34 only receives the force of pushing upward from the contact portion 56 , and swings about the first swing shaft 61 . do not do. Further, the fourth protrusion 54 of the second swing gate 33 contacts and presses the second cam surface 72 of the second stopper 35 , and the pressing force causes the second stopper 35 to move around the second swing shaft 71 as a fulcrum. Then, it tilts forward and moves to the second allowable position.

After that, due to the conveying force applied to the document from the separation roller 15, the document swings about the contact point with the second gate bar 52 so that the right side of the document catches up with the left side. When the leading edge of the document comes into contact with the first gate bar 42 and presses the first gate bar 42, the entire first rocking gate 32 pivots about the first gate shaft 41 so that the first gate bar 42 tilts forward. swing to. Before the document comes into contact with the first gate bar 42 and the second gate bar 52, the first gate bar 42 and the second gate bar 52 are aligned in the horizontal direction. When the document swings about the fulcrum and comes into contact with the first gate bar 42, the leading edge of the document is no longer skewed in the width direction. In addition, the second stopper 35 tilts forward about the second swing shaft 71 , so that the upper surface of the second stopper 35 moves forward of the contact portion 46 of the first projection 43 of the first swing gate 32 . positioned. Therefore, even if the first swing gate 32 swings, the contact portion 46 does not contact the upper surface of the second stopper 35 . As the first rocking gate 32 rocks, the second protrusion 44 contacts and presses the first cam surface 62 of the first stopper 34, and the pressing force exerts the force shown in FIGS. The first stopper 34 tilts rearward about the first swing shaft 61 to move to the first allowable position. As a result, the lower surface of the first stopper 34 shifts to the rear side of the contact portion 56 of the third protrusion 53, and the contact between the lower surface of the first stopper 34 and the contact portion 56 of the third protrusion 53 is released. be done. As a result, the restriction on the swinging motion of the second swinging gate 33 is released, the second gate bar 52 of the second swinging gate 33 tilts, and the document is placed in a state in which the positions of the leading edge of the document are aligned on the left and right sides. 1 gate bar 42 and second gate bar 52 are crossed.

Next, consider the case where the document is skewed with the right edge leading the left edge. As this skew progresses, the leading edge of the document comes into contact with the first gate bar 42 before coming into contact with the second gate bar 52 . As the document is conveyed, the document presses the first gate bar 42, and the entire first swing gate 32 swings about the first gate shaft 41 so that the first gate bar 42 tilts forward. Due to this swinging, the contact portion 46 of the first protrusion 43 of the first swing gate 32 contacts the upper surface of the second stopper 35, and further swinging of the first swing gate 32 is prevented. The second stopper 35 is arranged so that a straight line orthogonal to the upper surface of the second stopper 35 passes slightly rearward of the center of the second swing shaft 71 at the contact portion of the contact portion 46 . Therefore, even if the contact portion 56 comes into contact with the lower surface of the first stopper 34 , the first stopper 34 only receives the force of pushing upward from the contact portion 56 and swings about the second swing shaft 71 . do not do. Further, the second protrusion 44 of the first rocking gate 32 contacts and presses the first cam surface 62 of the first stopper 34 , and the pressing force causes the first stopper 34 to move the first rocking shaft 61 as a fulcrum. Then, it tilts rearward and moves to the first allowable position.

After that, due to the conveying force applied to the document by the separation roller 15, the document swings about the point of contact with the first gate bar 42 so that the left side of the document catches up with the right side. When the leading edge of the document comes into contact with the second gate bar 52 and presses the second gate bar 52, the second swing gate 33 as a whole pivots about the second gate shaft 51 so that the second gate bar 52 tilts forward. swing to. Before the document contacts the first gate bar 42 and the second gate bar 52, the first gate bar 42 and the second gate bar 52 are aligned in the horizontal direction. When the document swings around the fulcrum and comes into contact with the second gate bar 52, the skew of the leading edge of the document in the width direction is eliminated. At this time, the first stopper 34 tilts rearward about the first swing shaft 61 , so that the lower surface of the first stopper 34 contacts the contact portion 56 of the third projection 53 of the second swing gate 33 . located behind. Therefore, even if the second swing gate 33 swings, the contact portion 56 does not contact the lower surface of the first stopper 34 . Then, when the second swing gate 33 swings, the fourth projection 54 contacts and presses the second cam surface 72 of the second stopper 35, and the pressing force causes the second stopper 35 to move to the second position. It tilts forward about the swing shaft 71 and moves to the second allowable position. As a result, the upper surface of the second stopper 35 shifts to the front side of the contact portion 46 of the first protrusion 43, and the contact between the upper surface of the second stopper 35 and the contact portion 46 is released. As a result, the restriction on the swinging motion of the first swinging gate 32 is released, the first gate bar 42 of the first swinging gate 32 is tilted, and the document is placed in a state in which the leading edges of the document are aligned on the left and right sides. 1 gate bar 42 and second gate bar 52 are crossed.

<Effect>
As described above, the skew of the document can be corrected by the inexpensive configuration including the first rocking gate 32, the second rocking gate 33, the first stopper 34, and the second stopper 35. FIG.

<Other embodiments>
A skew correction mechanism 81 (an example of a correction mechanism) shown in FIGS. 12 and 13 includes a first rocking gate 82 , a second rocking gate 83 , a first stopper 84 and a second stopper 85 . The first swing gate 82 corresponds to the first swing gate 32 in FIG. 2, and the second swing gate 83 corresponds to the second swing gate 33 in FIG.

As shown in FIG. 12, the first rocking gate 82 integrally has a first gate shaft 91, a first gate bar 92, a first projection 93 and a second projection 94, each of which is shown in FIG. The structure corresponds to the first gate shaft 41 , the first gate bar 42 , the first projection 43 and the second projection 44 . The first gate shaft 91 extends in the left-right direction and is swingably held by the housing 2 (see FIG. 1). The first gate shaft 91 is biased counterclockwise in FIG. 12 by the elastic force of a torsion coil spring (not shown). The first gate bar 92 extends radially of the first gate shaft 91 from the right end of the first gate shaft 91 . The first gate bar 92 protrudes into the transport path 14 from below the transport path 14 in a state in which the first gate bar 92 is not in contact with another member (original document). Hereinafter, for convenience of explanation, the front, rear, top and bottom are defined with the side where the first gate bar 92 extends from the first gate shaft 91 as the upper side. The first protrusion 93 has a plate shape protruding radially from the peripheral surface of the first gate shaft 91 . The second protrusion 94 protrudes radially from a position on the peripheral surface of the first gate shaft 91 opposite to the first protrusion 93 across the center of the first gate shaft 91 . The protrusion amount of the second protrusion 94 is larger than the protrusion amount of the first protrusion 93 . The downstream end of the second protrusion 94 in the clockwise direction as viewed from the left side has rounded corners.

The second swing gate 83 is arranged on the left side of the first swing gate 82, like the second swing gate 33 in FIG. As shown in FIG. 13, the second swing gate 83 integrally has a second gate shaft 101, a second gate bar 102, a third projection 103 and a fourth projection 104, each of which is shown in FIG. The structure corresponds to the two gate shafts 51 , the second gate bar 52 , the third protrusion 53 and the fourth protrusion 54 . The second gate shaft 101 is arranged on the same axis as the first gate shaft 91 and is swingably held by the housing 2 (see FIG. 1). The second gate shaft 101 is biased clockwise in FIG. 13 by the elastic force of a torsion coil spring (not shown). The second gate bar 102 extends radially of the second gate shaft 101 from the left end of the second gate shaft 101 . The second gate bar 102 protrudes into the transport path 14 from below the transport path 14 in a state where the second gate bar 102 is not in contact with another member (original document). The third protrusion 103 has a plate shape protruding radially from the peripheral surface of the second gate shaft 101 . The fourth protrusion 104 protrudes radially from a position opposite to the third protrusion 103 on the peripheral surface of the second gate shaft 101 across the center of the second gate shaft 101 . The amount of protrusion of the fourth protrusion 104 is larger than the amount of protrusion of the third protrusion 103 . The corners of the downstream end of the fourth protrusion 104 that is counterclockwise viewed from the right side are rounded.

The first stopper 84 is arranged behind the first gate shaft 91 and the second gate shaft 101 . The first stopper 84 is formed in a plate shape having a width that straddles the second projecting portion 94 and the fourth projecting portion 104 and faces each other. The tip surface of the first stopper 84 forms a first cam surface 111 that is inclined forward and upward. The first stopper 84 is biased forward by the elastic force of a first elastic body 112 that is a compression spring.

The second stopper 85 is arranged in front of the first gate shaft 91 and the second gate shaft 101 . The second stopper 85 is formed in a plate shape having a width that straddles the first protrusion 93 and the third protrusion 103 and faces each other. The tip end surface of the second stopper 85 forms a second cam surface 113 that is inclined rearwardly downward. The second stopper 85 is urged forward by the elastic force of a first elastic body 114 made of a compression spring.

<Skew correction operation>
Before the document contacts the first gate bar 92 and the second gate bar 102, the first stopper 84 is positioned at the first blocking position indicated by the solid line in FIG. 12, as indicated by the solid line in FIGS. The second stopper 85 is located at the second blocking position indicated by solid lines in FIG. In this state, the third protrusion 103 of the second swing gate 83 is positioned at a position spaced apart from the lower surface of the first stopper 84 . Also, the fourth protrusion 104 is located at a position spaced upward from the second cam surface 113 of the second stopper 85 . The first protrusion 93 of the first rocking gate 82 faces the upper surface of the second stopper 85 with a gap, and the second protrusion 94 faces the first cam surface 111 of the first stopper 84. It is located at a position spaced apart on the lower side.

First, consider the case where the document is skewed with the right edge leading the left edge. As the skew progresses, the leading edge of the document comes into contact with the first gate bar 92 before coming into contact with the second gate bar 102 . As the document is conveyed, the document presses the first gate bar 92, and the entire first swing gate 82 swings about the first gate shaft 91 so that the first gate bar 92 tilts forward. 12, the first protrusion 93 of the first swing gate 82 comes into contact with the upper surface of the second stopper 85, thereby causing the first swing gate 82 to move further. Rocking is prevented. Also, the second projection 94 of the first rocking gate 82 abuts against and presses the first cam surface 111 of the first stopper 84, and the pressing force causes the first stopper 84 to slide rearward as shown in FIG. to the first allowable position indicated by the two-dot chain line.

After that, due to the conveying force applied to the document by the separation roller 15, the document swings about the point of contact with the first gate bar 92 so that the left side of the document catches up with the right side. When the leading edge of the document comes into contact with the second gate bar 102 and presses the second gate bar 102, the entire second rocking gate 83 pivots on the second gate shaft 101 so that the second gate bar 102 tilts forward. swing to. At this time, the first stopper 84 slides rearward, so that the lower surface of the first stopper 84 is positioned rearward with respect to the third protrusion 103 of the second swing gate 83 . Therefore, even if the second swing gate 83 swings, the third protrusion 103 does not come into contact with the lower surface of the first stopper 84 . As the second rocking gate 83 rocks, the fourth projection 104 contacts and presses the second cam surface 113 of the second stopper 85, and the pressing force moves the second stopper 85 forward. slide. As a result, the upper surface of the second stopper 85 shifts to the front side of the first protrusion 93, and the contact between the upper surface of the second stopper 85 and the first protrusion 93 is released. As a result, the restriction on the swinging of the first swing gate 82 is released, and the first gate bar 92 of the first swing gate 82 tilts. 1 gate bar 92 and second gate bar 102 are crossed.

Next, consider the case where the document is skewed with the left edge of the document leading the right edge. When the document advances obliquely, the leading edge of the document contacts the second gate bar 102 before contacting the first gate bar 92 . As the document is conveyed, the document presses the second gate bar 102, and the entire second swing gate 83 swings around the second gate shaft 101 so that the second gate bar 102 tilts forward. Due to this swinging, the third protrusion 103 of the second swinging gate 83 comes into contact with the lower surface of the first stopper 84, and further swinging of the second swinging gate 83 is prevented. Further, the fourth protrusion 104 of the second rocking gate 83 contacts and presses the second cam surface 113 of the second stopper 85, and the pressing force causes the second stopper 85 to slide forward as shown in FIG. It moves to the second allowable position indicated by the two-dot chain line.

After that, due to the conveying force applied to the document from the separation roller 15, the document swings about the contact point with the second gate bar 102 so that the right side of the document catches up with the left side. When the leading edge of the document comes into contact with the first gate bar 92 and presses the first gate bar 92, the entire first rocking gate 82 pivots on the first gate shaft 91 so that the first gate bar 92 tilts forward. swing to. At this time, the upper surface of the second stopper 85 is positioned forward with respect to the first protrusion 93 of the first swing gate 82 by sliding the second stopper 85 forward. Therefore, even if the first swing gate 82 swings, the first protrusion 93 does not come into contact with the upper surface of the second stopper 85 . As the first rocking gate 82 rocks, the second projection 94 contacts and presses the first cam surface 111 of the first stopper 84, and the pressing force moves the first stopper 84 toward the rear side. 12 to the first allowable position indicated by the two-dot chain line in FIG. As a result, the lower surface of the first stopper 84 shifts to the rear side of the third protrusion 103, and the contact between the lower surface of the first stopper 84 and the third protrusion 103 is released. As a result, the regulation of the swinging of the second swing gate 83 is released, the second gate bar 102 of the second swing gate 83 tilts, and the document is moved in a state in which the positions of the leading edge of the document are aligned on the left and right sides. 1 gate bar 92 and second gate bar 102 are crossed.

<Effect>
This configuration of the skew correction mechanism 81 can also provide the same effects as the configuration of the skew correction mechanism 31 shown in FIG.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms.

For example, the medium conveying device according to the present invention is not limited to the image reading device 1, and can be widely applied to devices such as printers that require a structure for conveying media such as paper.

In addition, various design changes can be made to the above configuration within the scope of the matters described in the claims.

1: Image reading device 15: Separation roller 17: Conveyance roller 31, 81: Skew correction mechanism 32, 82: First rocking gate 33, 83: Second rocking gate 34, 84: First stopper 35, 85: Second stopper 43, 93: first protrusion 44, 94: second protrusion 53, 103: third protrusion 54, 104: fourth protrusion 61: first swing shaft 62, 111: first cam surface 64: first elastic body 71: second swing shaft 72, 113: second cam surface 74: second elastic body

Claims (7)

a separation roller that separates and conveys the media one by one;
a conveying roller disposed downstream of the separation roller in a medium conveying direction and configured to convey the medium in the conveying direction;
a correction mechanism disposed between the separation roller and the conveying roller for correcting skew of the medium;
The correction mechanism is
a one-side swinging member provided swingably about an axis extending in a width direction perpendicular to the conveying direction, and having a first gate bar, a first protrusion, and a second protrusion;
the other-side swinging member provided swingably about the axis extending in the width direction and having a second gate bar, a third protrusion, and a fourth protrusion;
A first blocking position that blocks movement of the third projection and a first allowable position that permits movement of the third projection along with the movement of the second projection caused by the rocking motion of the one-side rocking member. a first stopper movably provided between
A second blocking position for blocking movement of the first projection and a second allowing position for permitting movement of the first projection along with the movement of the fourth projection due to the rocking movement of the other-side rocking member. a second stopper movably provided between
including
In the initial state, the first stopper is positioned at the first blocking position, the second stopper is positioned at the second blocking position, and the one-side swinging member swings due to contact of the medium with the first gate bar. As the second protrusion moves due to movement, the first stopper moves from the first blocking position to the first allowing position, and the medium contacts the second gate bar to move the other side swinging member. a medium conveying device, wherein the second stopper moves from the second blocking position to the second allowing position in accordance with the movement of the fourth protrusion caused by the rocking of the second stopper. The media transport device of claim 1, comprising:
The medium transport device, wherein the first gate bar and the second gate bar are arranged along a direction orthogonal to the transport direction in an initial state. 3. The medium transport device according to claim 1 or 2,
a first elastic body that biases the first stopper from the first allowable position toward the first blocking position;
and a second elastic body that biases the second stopper from the second allowable position toward the second blocking position. The medium transport device according to any one of claims 1 to 3,
the first stopper and the second stopper are provided so as to be capable of swinging independently around a first swing shaft and a second swing shaft extending in the width direction, respectively;
The first swing shaft of the first stopper is arranged at a position where a force component around the first swing shaft is not generated by the contact of the third projection,
The medium conveying device, wherein the second swing shaft of the second stopper is arranged at a position where a force component around the second swing shaft is not generated due to the contact of the first protrusion. The media transport device of claim 4 , comprising:
The first stopper has a first cam surface that abuts on the second projection and rocks the first stopper about the first rocking shaft as the second projection moves,
The second stopper has a second cam surface that abuts on the fourth projection and rocks the second stopper about the second rocking shaft as the fourth projection moves. media transport device. The media transport device of claim 1, comprising:
The first stopper and the second stopper are independently slidable in a first direction orthogonal to the width direction,
The first stopper is formed in a shape in which the third protrusion abuts from a second direction orthogonal to both the width direction and the first direction,
The medium conveying device, wherein the second stopper is formed in such a shape that the first protrusion abuts from the second direction. The media transport device of claim 6, comprising:
The first stopper has a first cam surface that converts a force received from the second protrusion into a force in the first direction when the second protrusion abuts from the second direction,
The second stopper has a second cam surface that converts a force received from the fourth protrusion into a force in the first direction when the fourth protrusion abuts from the second direction, Media transport.

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