Patent Description:
Conventionally, a sheet post-processing apparatus is known, which can perform a binding processing in which a plurality of sheets on which an image is formed by an image forming apparatus such as a copying machine or a printer are stacked and then the stack of sheets is stapled with staples, a punching processing in which holes are formed in the stack of sheets by a punching apparatus, and the like. The above-described sheet post-processing apparatus is utilized when performing the post-processing such as the binding processing for a relatively large number of sheets.

As a method for connecting the image forming apparatus and the sheet post-processing apparatus, there is proposed a method for disposing a relay conveyance apparatus between the image forming apparatus and the sheet post-processing apparatus. For example, Patent Document <NUM> discloses a relay conveyance device including at least two inversion paths which pass at least two inversion units, a first branching part branching to at least one of the two inversion paths, and a first merging part merging at least the two inversion paths. The first branching part and the first merging part are controlled so as to alternately switch the inversion paths and to convey the sheet, and the inter-sheet time of the sheet passing through the first merging part is measured and then the conveyance of sheet in at least the two inversion paths is controlled such that the inter-sheet times becomes uniform.

As in the relay conveyance apparatus described in Patent Document <NUM>, the conveyance paths on which the sheet stop position and the processing apparatus are provided are provided, and the distances between the branching part and the merging part on the conveyance paths are set to equal, so that the constant inter-sheet time can be maintained before branching and after merging without requiring complicated control.

By the way, in a configuration including a plurality of conveyance units disposed in the upper-and-lower direction as disclosed in Patent Document <NUM>, it is necessary to draw out the conveyance unit forward from the relay conveyance apparatus when the sheet jamming occurred in the lower conveyance unit is treated. At this time, in order to smoothly carry out the treatment of the sheet jamming, it is necessary to draw out the unit at least over the width of the conveyance path (the sheet width), then to open and close the conveyance guide, and then remove the sheet. Therefore, there is a problem that it is necessary to leave a large space in front of the relay conveyance apparatus, and that when there is no space, the user has to move to a position where he does not interfere with the drawing of the conveyance unit.

Patent Document <NUM> discloses a relay conveyance apparatus including an opening/closing cover for treating the sheet jamming whose one end side is supported by a supporting member, a first hinge part which supports the opening/closing cover so as to be turnable upward and downward at the upper end side of the supporting member, and a second hinge part which supports the supporting member to a base member so as to be turnable upward and downward at the lower end side of the supporting member. By the two-state hinge function of the supporting member, the posture of the opening/closing cover after opening is substantially parallel to that before opening, and a jam treatment space having a uniform height is formed below the lower surface of the opening/closing cover.

<CIT> discloses a sheet conveyance apparatus according to the preamble of claim <NUM>.

In the configuration disclosed in Patent Document <NUM>, the opening/closing cover is displaced upward in a state in which the posture of the opening/closing cover after opening is maintained substantially parallel to the posture before opening. In the configuration in which the conveyance units are disposed in the upper-and-lower direction, since there is no space for displacing the opening/closing cover upward, the same drawing-out operation of the conveyance unit as in the prior art is required.

In view of the above problems, it is an object of the present invention to provide a sheet conveyance apparatus including two or more conveyance paths disposed in parallel in the upper-and-lower direction and capable of easily removing a sheet stopped in the lower conveyance path, and an image forming system including the same.

In order to achieve the above purpose, a sheet conveyance apparatus of the present invention includes: a first conveyance unit which includes a first upper conveyance guide facing an upper surface of a sheet, a first lower conveyance guide facing a lower surface of the sheet and a conveyance member conveying the sheet along the first upper conveyance guide and the first lower conveyance guide, and forms a first sheet conveyance path; a second conveyance unit which is disposed below the first conveyance unit in parallel, includes a second upper conveyance guide facing the upper surface of the sheet, a second lower conveyance guide facing the lower surface of the sheet and a conveyance member conveying the sheet along the second upper conveyance guide and the second lower conveyance guide, and forms a second sheet conveyance path; and an apparatus main body in which the first conveyance unit and the second conveyance unit are housed, wherein the second conveyance unit can be drawn out horizontally to a front side of the apparatus main body along a front-and-rear direction perpendicular to a sheet conveyance direction with respect to the apparatus main body, the second upper conveyance guide of the second conveyance unit includes: a guide main body part turnable upward and downward with respect to the apparatus main body with a rear end edge as a turning support shaft and a front end edge as a turning end; and a movable guide part coupled to the turning end of the guide main body part via a hinge part in a turnable manner.

According to the first configuration of the present invention, the movable guide part of the upper conveyance guide of the lower conveyance unit is turned upward around the hinge portion, so that interference with the upper conveyance unit can be avoided, and the upper conveyance guide can be smoothly opened and closed over a wide range during the sheet jamming treatment work. Further, the drawing amount of the lower conveyance unit can be reduced as compared with the conventional one, and it is not necessary to leave a large space for drawing out the lower conveyance unit in front of the sheet conveyance apparatus. Further, since the movement of the user at the time of the draw-out operation of the lower conveyance unit is suppressed, the workability of the sheet jamming treatment is improved.

Hereinafter, with reference to the drawings, one embodiment of the present invention will be described. <FIG> is a view schematically showing an inner structure of an image forming system <NUM> provided with a relay conveyance apparatus <NUM> as an example of a sheet conveyance apparatus of the present invention. With reference to <FIG>, the image forming system <NUM> including an image forming apparatus <NUM>, the relay conveyance apparatus <NUM>, and a sheet post-processing apparatus <NUM> will be described.

The image forming apparatus <NUM> is an inkjet recording type printer, and includes a sheet feeding part <NUM> disposed in the lower portion of the image forming apparatus <NUM>, a sheet conveyance part <NUM> which feeds the sheet S stored in the sheet feeding part <NUM> to an image forming part <NUM>, and the image forming part <NUM> disposed above the sheet feeding part <NUM>.

The image forming part <NUM> includes a print head 6a and a conveyance part 6b disposed so as to face the print head 6a. The conveying part 6a includes an endless conveyance belt wound around a plurality of rollers including a drive roller. The sheet S conveyed by the sheet conveyance part <NUM> passes under the print head 6a in a state of being attracted and held by the conveyance belt 7a by a sheet suction part provided in the inside space of the conveyance belt 7a. The sheet S on which the predetermined image is recorded by the image forming part <NUM> is discharged from a discharge rollers pair <NUM> and carried into the relay conveyance apparatus <NUM>.

The relay conveyance apparatus <NUM> is disposed independently between the image forming apparatus <NUM> and the sheet post-processing apparatus <NUM>, and relays the sheet S discharged from the image forming apparatus <NUM> to the sheet post-processing apparatus <NUM>. The relay conveyance apparatus <NUM> performs an inversion processing in which the sheet S on which the image is recorded by the image forming apparatus <NUM> is turned upside down and a drying processing in which the ink on the sheet S is dried. As shown in <FIG>, the sheet S carried in from the relay carry-in port <NUM> of the relay conveyance apparatus <NUM> passes through a first conveyance path 52a and is conveyed to a first inversion conveyance path 53a. The first inversion conveyance path 53a turns the sheet S upside down by switching (switching back) the conveyance direction of the sheet S conveyed from the first conveyance path 52a.

A second conveyance path 52b branched from the first conveyance path 52a is provided, and the sheet S passed through the second conveyance path 52b is conveyed to a second inversion conveyance path 53b. The second inversion conveyance path 53b turns the sheet S upside down by switching (switching back) the conveyance direction of the sheet S conveyed from the second conveyance path 52b.

The sheet S which is turned upside down by the first inversion conveyance path 53a or the second inversion conveyance path 53b is conveyed to a third conveyance path 52c. The sheet S is conveyed to a first bypass conveyance path 54c and a second bypass conveyance path 54b branched from a third conveyance path 52c at the branching part DB. The first bypass conveyance path 54a and the second bypass conveyance path 54b are provided with a first correction unit <NUM> and a second correction unit <NUM>, respectively. The first correction unit <NUM> and the second correction unit <NUM> correct the position of the sheet S in the width direction of the sheet S (the direction perpendicular to the paper plane of <FIG>).

In the first bypass conveyance path 54a and the second bypass conveyance path 54b, a distance from the branching part DB to the merging part DJ is equal. Further, a distance from the branching part DB to the sheet stop position (the horizontal portion in <FIG>) is equal to a conveyance interval of the sheets S (an interval between the sheets). Therefore, for example, by stopping the first sheet S turned upside down in the first inversion conveyance path 53a in the second bypass conveyance path 54b and stopping the second sheet S turned upside down in the second inversion conveyance path 53b in the first bypass conveyance path 54a, the stopped sheet S can be conveyed again while maintaining the interval between the sheets. That is, before one of the first inversion conveyance path 53a and the second inversion conveyance path 53b completes the turning operation of the first sheet S, the turning operation of the second sheet S can be started in the other of the first inversion conveyance path 53a and the second inversion conveyance path 53b.

In the same manner, by alternately carrying the sheet S into the first correction unit <NUM> and the second correction unit <NUM> disposed on the first bypass conveyance path 54a and the second bypass conveyance path 54b, respectively, before one of the first correction unit <NUM> and the second correction unit <NUM> completes the position correcting operation of the first sheet S, the position correcting operation of the second sheet S can be started in the other of the first correction unit <NUM> and the second correction unit <NUM>.

As a result, the waiting time for the turning and the position correcting of the sheet S can be shortened, and the processing efficiency (a number of sheets processed per unit time) of the sheet S by the relay conveyance apparatus <NUM> can be enhanced.

The sheet S passed through the first bypass conveyance path 54a and the second bypass conveyance path 54b is conveyed to a fourth conveyance path 52d at the merging part DJ. The sheet S passes through the fourth conveyance path 52d, and is carried into the sheet post-processing apparatus <NUM> through a relay carry-out port <NUM>.

In addition, an in-body discharge conveyance path <NUM> branched from the fourth conveyance path 52d is provided, and the sheet S passed through the in-body discharge conveyance path <NUM> is discharged to a collection tray <NUM> by an in-body discharge rollers pair <NUM>. When a sheet jamming occurs in the sheet post-processing apparatus <NUM>, the conveyance path is switched by a third branch guide <NUM> provided at a branching part of the fourth conveyance path 52d and the in-body discharge conveyance path <NUM>, and the next sheet S existing in the relay conveyance apparatus <NUM> is discharged to the collection tray <NUM> via the in-body discharge conveyance path <NUM> and the in-body discharge rollers pair <NUM>.

A conveyance rollers pair <NUM> (conveyance members) for conveying the sheet S is disposed in place on the first conveyance path 52a to the fourth conveyance path 52d, the first bypass conveyance path 54a, the second bypass conveyance path 54b, and the in-body discharge conveyance path <NUM>.

Inside the sheet post-processing apparatus <NUM>, there are provided a punching apparatus <NUM> which punches the carried-in sheet S, a stapler <NUM> which stacks a plurality of the carried-in sheets S, aligns the ends of the stack of the sheets S, and binds them with staples, and a binding/folding unit <NUM> which staples the center of the stack of sheets S and then folds it around the stapled portion to form a booklet. On the side surface of the sheet post-processing apparatus <NUM>, there are provided a main tray 34a which can be lifted and lowered to a position suitable for discharging the sheet S, a sub-tray 34b fixed to the upper portion of the sheet post-processing apparatus <NUM>, and a booklet tray 34c on which a bundle of the sheets S folded into a booklet shape by the binding/folding unit <NUM> is discharged.

<FIG> is a perspective view showing a first conveyance unit 70a and a second conveyance unit 70b constituting the first bypass conveyance path 54a and the second bypass conveyance path 54b. The first conveyance unit 70a (an upper conveyance unit) and the second conveyance unit 70b (the lower conveyance unit) are disposed in parallel so as to be overlapped in the upper-and-lower direction. <FIG> shows a state in which the second conveyance unit 70b is drawn out from below the first conveyance unit 70a in the sheet width direction (the white arrow direction in <FIG>) perpendicular to the conveyance direction.

The first conveyance unit 70a is disposed above the second conveyance unit 70b and below the collection tray <NUM>, and includes a first upper conveyance guide <NUM> and a first lower conveyance guide <NUM> which face the upper and lower surfaces of the sheet S. The first upper conveyance guide <NUM> and the first lower conveyance guide <NUM> forms the conveyance surfaces (the conveyance guide) of the first bypass conveyance path 54a (see <FIG>). The upper rollers constituting the conveyance rollers pairs <NUM> in the first bypass conveyance path 54a are supported by the first upper conveyance guide <NUM>. The lower roller constituting the conveyance rollers pairs <NUM> are supported by the first lower conveyance guide <NUM>.

The second conveyance unit 70b is disposed below the first conveyance unit 70a, and includes a second upper conveyance guide <NUM> and a second lower conveyance guide <NUM> which face the upper and lower surfaces of the sheet S. The second upper conveyance guide <NUM> and the second lower conveyance guide <NUM> form the conveyance surface (the conveyance guide) of the second bypass conveyance path 54b (see <FIG>). The upper roller constituting the conveyance rollers pairs <NUM> in the second bypass conveyance path 54a are supported by the second upper conveyance guide <NUM>. The lower roller constituting the conveying rollers pairs <NUM> are supported by the second lower conveyance guide <NUM>.

The second upper conveyance guide <NUM> is supported so as to be opened and closed in the upper-and-lower direction with respect to the second lower conveyance guide <NUM>, with one end side in the width direction perpendicular to the conveyance direction of the sheet S (the rear side of the relay conveyance apparatus <NUM>, and the rear side of <FIG>) as a turning support shaft 75a and the front side of the relay conveyance apparatus <NUM> (the front side in <FIG>) opposite to the turning support shaft 75a as the turning side.

When the sheet S carried into the second conveyance unit 70b (the second bypass conveyance path 54b) is jammed, as shown in <FIG>, the second conveyance unit 70b is drawn out from below the first conveyance unit 70a to the front side of the relay conveyance apparatus <NUM>.

<FIG> is a perspective view showing a state in which the second upper conveyance guide <NUM> is opened. <FIG> is a partially enlarged view showing the hinge part 75d of the second upper conveyance guide <NUM> in <FIG> and its periphery. From the state shown in <FIG>, when the turning end of the second upper conveyance guide <NUM> is turned upward to open the conveyance surfaces from the front side of the relay conveyance apparatus <NUM> (the left front side in <FIG>) and the upper and lower conveyance rollers constituting the conveyance roller pair <NUM> separates away each other, the sheet S jammed in the second conveyance unit 70b can be pulled out to the front side of the relay conveyance apparatus <NUM> and removed.

Here, the first conveyance unit 70a is disposed above the second upper conveyance guide <NUM>, and interferes with the first conveyance unit 70a when the second upper conveyance guide <NUM> is turned upward. Therefore, in order to open the conveyance surfaces of the second bypass conveyance path 54b in a wide range by increasing the turning angle of the second upper conveyance guide <NUM>, it is necessary to increase the drawing amount of the second conveyance unit 70b with respect to the first conveyance unit 70a.

Therefore, in the present embodiment, the second upper conveyance guide <NUM> includes a guide main body part 75b and a movable guide part 75c. The guide main body part 75b has a front turning end 75b1 (the front end portion in <FIG>) that can be turned upward and downward with the rear end edge on the rear side of the relay conveyance apparatus <NUM> as a turning support shaft 75a (see <FIG>). The movable guide part 75b is supported by the turning end 75b1 of the guide main body part 75a via a hinge part 75d.

<FIG> is a perspective view showing a state in which the movable guide part 75c is turned relative to the main guide body part 75b from the state shown in <FIG>. <FIG> is a partially enlarged view of the hinge part 75d of the second upper conveyance guide <NUM> in <FIG> and its periphery. As shown in <FIG> and <FIG>, the movable guide part 75c of the second upper conveyance guide <NUM> is turned upward around the hinge part 75d to avoid interference with the first conveyance unit 70a, and the second upper conveyance guide <NUM> can be opened and closed smoothly and in a wide range during the sheet jamming treatment.

In addition, the drawing amount of the second conveyance unit 70b can be reduced to about <NUM>/<NUM> to <NUM>/<NUM> of the conventional amount, and it is not necessary to leave a large space for drawing the second conveyance unit 70b in front of the relay conveyance apparatus <NUM>. Further, since the movement of the user at the time of the drawing operation of the second conveyance unit 70a is also suppressed, the workability of the sheet jamming treatment is improved.

If the hinge part 75d is positioned on the rear side (the inside) of the front side end (the left front side in <FIG>) of the first conveyance unit 70a in a state where the second conveyance unit 70b is drawn out, it becomes difficult to turn the movable guide part 75c. In order to smoothly avoid interference with the first conveyance unit 70a owing to the turning of the movable guide part 75c, it is preferable that the hinge part 75d is located on the front side (the outside) of the front end edge of the first conveyance unit 70a in a state where the second conveyance unit 70b is drawn out.

<FIG> is a perspective view showing the collection tray <NUM> provided inside the relay conveyance apparatus <NUM>. The collection tray <NUM> has a tray body part <NUM> and a tray movable part <NUM>. The tray body part <NUM> is fixed to the rear frame 80a of the relay conveyance apparatus <NUM>. The tray movable part <NUM> is supported by the front side (the front side in <FIG>) of the tray body part <NUM> via a hinge part <NUM> in a turnable manner.

<FIG> and <FIG> are perspective views showing the collection tray <NUM> and the first conveyance unit 70a in a state in which the tray movable part <NUM> is disposed in a sheet receiving position and a retreat position, respectively.

The first upper conveyance guide <NUM> is supported so as to be opened and closed in the upper-and-lower direction with respect to the first lower conveyance guide <NUM>, with one end side in the width direction perpendicular to the conveyance direction of the sheet S (the back side of the relay conveyance apparatus <NUM>, the right side of <FIG>) as a turning support shaft 71a and the front side of the relay conveyance apparatus <NUM> (the left side in <FIG>) opposite to the turning support shaft 71a as a turning end.

At a time of a normal image forming operation, as shown in <FIG> and <FIG>, the tray movable part <NUM> is disposed in the sheet receiving position. The tray movable part <NUM> disposed in the sheet receiving position is on the same plane as the tray body part <NUM>, and forms a sheet stacking surface on which the sheet S discharged from the in-body discharge rollers pair <NUM> is stacked, together with the tray body part <NUM>. As shown in <FIG>, the collection tray movable part <NUM> is movable to a retreat position turned upward from the sheet receiving position.

<FIG> is a perspective view showing a state in which the first upper conveyance guide <NUM> is opened. When the sheet S carried in the first conveyance unit 70a (the first bypass conveyance path 54a) is jammed, the turning end of the first upper conveyance guide <NUM> is turned upward to open the conveyance surfaces from the front side of the relay conveyance apparatus <NUM> (the left side in <FIG>), and the upper and lower conveyance rollers constituting the conveyance rollers pairs <NUM> are separated away each other. As a result, the jammed paper S can be pulled out to the front side of the relay conveyance apparatus <NUM> (the left side in <FIG>) and removed.

As shown in <FIG>, the tray movable part <NUM> is positioned just above the first upper conveyance guide <NUM>. Therefore, when the first upper conveyance guide <NUM> is turned upward, the tray movable part <NUM> is pushed up by the first upper conveyance guide <NUM> and shifted from the sheet receiving position to the retreat position.

Thus, even when the collection tray <NUM> is disposed just above the first bypass conveyance path 54a, interference between the collection tray <NUM> and the first upper conveyance guide <NUM> when the first upper conveyance guide <NUM> is opened can be avoided, and the first upper conveyance guide <NUM> can be smoothly opened and closed during the sheet jamming treatment work. Accordingly, the space for disposing the collection tray <NUM> can be saved, and the degree of freedom of layout in the relay conveyance apparatus <NUM> can be increased.

In addition, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the scope of the appended claims.

For example, in the above embodiment, an example in which the present invention is applied to the relay conveyance apparatus <NUM> connected to the image forming apparatus <NUM> is described, but for example, the present invention can be similarly applied when the image forming apparatus <NUM> and the sheet post-processing apparatus <NUM> are provided with two conveyance paths arranged in parallel in the upper-and-lower direction.

In the above embodiment, the relay conveyance apparatus <NUM> including the first conveyance unit 70a and the second conveyance unit 70b disposed in parallel in the upper-and-lower direction is described, but the present invention can also be applied to the case where the relay conveyance device has three or more conveyance units disposed in parallel in the upper-and-lower direction. In this case, the upper conveyance guide of the conveyance unit other than the uppermost conveyance unit may be provided with a guide body part and a movable guide part which are connected to each other via a hinge part.

Although an inkjet printer is shown as an example of the image forming apparatus <NUM> in the above embodiment, it goes without saying that the image forming apparatus <NUM> can be applied to a copying machine, a laser printer, a facsimile machine, or the like other than the inkjet printer.

Claim 1:
A sheet conveyance apparatus (<NUM>) comprising:
a first conveyance unit (70a) which includes a first upper conveyance guide (<NUM>) facing an upper surface of a sheet, a first lower conveyance guide (<NUM>) facing a lower surface of the sheet and a conveyance member (<NUM>) conveying the sheet along the first upper conveyance guide (<NUM>) and the first lower conveyance guide (<NUM>), and forms a first sheet conveyance path (54a);
a second conveyance unit (70b) which is disposed below the first conveyance unit (70a) in parallel, includes a second upper conveyance guide (<NUM>) facing the upper surface of the sheet, a second lower conveyance guide (<NUM>) facing the lower surface of the sheet and a conveyance member (<NUM>) conveying the sheet along the second upper conveyance guide (<NUM>) and the second lower conveyance guide (<NUM>), and forms a second sheet conveyance path (54b); and
an apparatus main body in which the first conveyance unit (70a) and the second conveyance unit (70b) are housed, characterized in that
the second conveyance unit (70b) can be drawn out horizontally to a front side of the apparatus main body along a front-and-rear direction perpendicular to a sheet conveyance direction with respect to the apparatus main body,
the second upper conveyance guide (<NUM>) of the second conveyance unit (70b) includes:
a guide main body part (75b) turnable upward and downward with respect to the apparatus main body with a rear end edge as a turning support shaft (75a) and a front end edge as a turning end (75b1); and
a movable guide part (75c) coupled to the turning end (75b1) of the guide main body part (75b) via a hinge part (75d) in a turnable manner.