JP3681556B2 - Sheet transport device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet conveying apparatus, and more particularly to a sheet conveying apparatus that can reliably convey even a sheet that has been deformed upward by printing or the like.
[0002]
[Prior art]
In Japanese Patent Application No. 6-101236, the present applicant has proposed an invention relating to a paper discharge device for a printing press. This paper discharge device is a device for receiving a postcard printed by a printing device, drying the ink while transporting it while holding it, and then dropping it into a tray for storage. This invention was disclosed in Japanese Patent Application Laid-Open No. 7-309596. The present invention will be described with reference to FIGS.
[0003]
A sheet conveying apparatus 100 is provided on the discharge port side of a printing apparatus (not shown). The sheet conveying apparatus 100 is connected to a paper discharge apparatus 101. The printing paper output from the printing apparatus is conveyed to the sheet conveying apparatus 100 and stored in the paper discharge apparatus 101.
[0004]
As shown in FIG. 6, the sheet conveying apparatus 100 has a conveying surface 102 for conveying a sheet. An opening 103 is provided in the center of the transport surface 102 along the transport direction. In other words, the two plate bodies are arranged at a predetermined interval along the direction orthogonal to the transport direction to constitute the transport surface 102. The opening 103 is provided with a sheet conveying means. The conveying means has a pair of pulleys 104 and a belt 105 wound around the pulleys 104. The upper side of the belt 105 in contact with the lower surface of the sheet 106 is in the conveying surface 102. The upper side of the belt 105 contacts the lower surface of the sheet 106 on the conveying surface 102 and conveys the sheet 106.
[0005]
As shown in FIG. 4, the paper discharge device 101 has a substantially box-shaped frame 110 as a main body. Two shafts 111 are arranged on both sides of the conveyed sheet 106 at the upper part of the frame 110. Each shaft 111 is provided with a holding means 112 composed of four wings.
[0006]
In the frame 110, a pair of upper and lower drive shafts 113 are arranged below the respective shafts 111. Two belts 114 are wound around each pair of drive shafts 113, 113. Each belt 114 is provided with a large number of paper receiving pieces 115 at predetermined intervals. As shown in FIG. 5, the distance between the left and right belts 114 and 114 is wide at the upper part and substantially coincides with the width of the sheet 106 at the lower part when viewed in a plane orthogonal to the conveyance direction of the sheet 106.
[0007]
A paper discharge tray 116 is provided at the bottom of the frame 110 so that it can be pulled out.
[0008]
The sheet 106 is printed by a printing apparatus (not shown) and then conveyed to the outside. The printed sheet 106 discharged from the printing apparatus is placed on the conveyance surface 102 of the sheet conveyance apparatus 100. The belt 105 moves in contact with the lower surface of the sheet 106 and moves the sheet 106 along the conveyance surface 102. The sheet 106 is held by the holding unit 112. As the shaft 111 rotates, the sheet 106 is placed between the paper receiving pieces 115 of the lower belt 114. The movement of the belt 114 moves the sheet 106 downward. The ink dries during conveyance and the position in the width direction is determined. Thereafter, the sheets 106 fall into the paper discharge tray 116 and are stacked.
[0009]
[Problems to be solved by the invention]
As shown in FIG. 7, the sheet 106 is warped in an upwardly convex state as viewed in a cross section perpendicular to the conveyance direction by being printed with ink on the upper surface side thereof. Accordingly, the central portion of the lower surface of the sheet 106 is above the conveying surface 102. In other words, the sheet 106 is in a state of being separated from the belt 105 of the conveying unit, which causes a conveyance failure of the sheet 106. Specifically, when the sheet 106 is a postcard, the sheet cannot be conveyed when the warpage amount is 3 mm or more.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet conveying apparatus that can convey a sheet (printing paper) without being affected by the warp.
[0011]
[Means for Solving the Problems]
A sheet conveying apparatus (1) according to claim 1, comprising a conveying surface (18) for conveying a sheet (printing paper 2) and a lower surface of the sheet on the conveying surface, the conveying of the sheet and conveyance means convey the sheet in contact with the central portion in the direction perpendicular to the direction (11),
Elevating means (elevating motor 5) for elevating and lowering the conveying means so that a portion in contact with the lower surface of the sheet moves at least between a position in the conveying surface and a position above the conveying surface;
Detecting means (sensor 20) for detecting a position of a central portion in a direction orthogonal to the conveying direction of the sheet being conveyed;
Control means (30) for controlling the elevating means so that the conveying means moves upward from a position in the conveying surface according to the position of the sheet detected by the detecting means . .
[0012]
Even when a sheet (printing paper 2) having a convex shape in the cross section orthogonal to the conveying direction is placed on the conveying surface (18), the upper end of the conveying means is above the conveying surface. Therefore, the conveying means (11) can contact the lower surface of the warped sheet, and can convey the printing paper.
[0013]
The sheet conveying apparatus (1) according to claim 2 conveys the sheet in contact with a conveying surface (18) for conveying the sheet (printing paper 2) and a lower surface of the sheet on the conveying surface. Transporting means (11) for moving up and down, and lifting means for moving the transporting means up and down (lifting and lowering) so that a portion in contact with the lower surface of the sheet moves at least between a position within the transporting surface and a position above the transporting surface. Motor 5), detection means (sensor 20) for detecting the position of the sheet being conveyed, and the conveyance means above the position in the conveyance surface according to the position of the sheet detected by the detection means in the sheet conveying apparatus for chromatic to move, and control means (30) for controlling the lifting means,
The detection means is a sensor (20) provided above the conveyance surface and detecting and outputting a distance to the upper surface of the sheet on the conveyance surface;
The control means (30) calculates the amount of warping of the sheet from the difference between the distance from the sensor to the conveyance surface and the distance from the sensor detected by the sensor to the upper surface of the sheet, The elevating means is controlled so that a portion in contact with the lower surface of the sheet moves upward from a position in the conveyance surface by a distance equal to or more than the amount of warpage .
[0015]
Sheet conveying apparatus according to claim 3 (1), in the sheet conveying apparatus according to claim 2, wherein the conveying surface (18) is centered along the conveyance direction of the sheet opening (16) is formed The conveying means is provided in the opening.
[0016]
The sheet conveying apparatus (1) according to claim 4 is the sheet conveying apparatus according to claim 3 , wherein the conveying means (11) includes a support base (8) and a pair of pulleys provided on the support base. (12) and a belt (13) wound around the pair of pulleys, and the upper side of the belt is between a position in the opening in the transport surface and a position above this. The elevating means elevates and lowers the support base so that it can move.
[0017]
Sheet conveying apparatus according to claim 5 (1) is the sheet transporting device mounting according to claim 1 or 2 SL, the sheet (printing sheet 2) is a convex shape on the cross section perpendicular to the conveying direction It is characterized by that.
[0018]
Sheet conveying apparatus according to claim 6 (1) is the sheet transporting device mounting according to claim 1 or 2 SL, the sheet (printing sheet 2) in the form of upwardly convex in a cross section perpendicular to the transport direction It is characterized by being applied to a sheet processing means for discharging.
[0019]
Sheet conveying apparatus according to claim 7 (1), in the sheet conveying apparatus according to claim 6, wherein said sheet processing means is characterized by an upper surface of the sheet is a printing apparatus that performs printing with ink .
[0020]
A sheet (printing paper 2) having a convex shape in a cross section perpendicular to the conveying direction is placed on the conveying surface (18). The detecting means detects the position of the sheet, and the control means adjusts the position of the conveying means according to this, so that the conveying means (11) can contact the lower surface of the warped sheet. That is, the sensor (20) measures the distance from the upper surface of the sheet. The distance between the sensor and the conveyance surface is known, and the control means calculates the amount of warpage of the sensor from the distance between the sensor and the upper surface of the sheet and the distance between the sensor and the conveyance surface. The control means controls the elevating means (elevating motor 5) to set the position of the upper end of the conveying means above the amount of warpage above the conveying surface so that the conveying means (11) can contact the lower surface of the warped sheet. To do. When the conveying means is operated, the warped printing paper is conveyed.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
An example of an embodiment of the present invention will be described with reference to FIGS.
The sheet conveying apparatus 1 of this example is arranged between a printing apparatus (not shown) and the paper discharge apparatus 101 shown in FIGS. 4 and 5, and prints the printed printing paper 2 (sheet) discharged from the printing apparatus. Used to carry into the paper discharge device 101.
[0022]
As shown in FIG. 1, the substrate 3 of this apparatus is attached to a paper discharge apparatus 101. A plurality of vertical guide bars 10 are fixed to the upper surface of the bottom plate 4 of the base 3. The guide rod 10 is provided with a conveying means 11 for the printing paper 2 so as to be movable up and down. The transport means 11 includes a support base 8, a pair of pulleys 12 provided on the support base 8, three belts 13 wound around the pair of pulleys 12, and the support base 8. And a conveyance motor 14 for driving the pulley 12. The belt 13 is made of urethane that is not easily deteriorated by ink. The belt 13 in this example is a round belt, but may be a flat belt.
[0023]
An elevating motor 5 as elevating means is fixed to the upper surface of the bottom plate 4. A feed screw 7 provided on the drive shaft 6 of the elevating motor 5 is engaged with a nut portion 9 formed on the support base 8. Therefore, if the elevating motor 5 is driven to rotate the drive shaft 6, the conveying means 11 can be raised and lowered with respect to the bottom plate 4 while being guided by the guide rod.
[0024]
A pair of conveyance guides 15, 15 are attached to the upper surface side of the substrate 3. The pair of conveyance guides 15 are arranged in the same plane with the opening 16 in the direction orthogonal to the conveyance direction of the printing paper 2. The upper surface of the bottom plate 17 of the conveyance guide 15 is a conveyance surface 18 with which the printing paper 2 to be conveyed contacts. The side plate 19 of the conveyance guide 15 guides the conveyance direction of the printing paper 2. The side plate 19 of the conveyance guide 15 is open on the entrance side of the printing paper 2. The distance between the pair of conveyance guides 15, 15, that is, the width of the opening 16 can be adjusted, and the printing paper 2 having a desired width can be guided.
[0025]
The conveying means 11 is provided in the opening 16. That is, when the elevating motor 5 moves the support base 8 up and down, the upper half of the belt 13 of the conveying means 11 is located between the position in the opening 16 in the conveying surface 18 and the position above this. You can move with.
[0026]
A sensor 20 for detecting the printing paper 2 is provided at a predetermined position above the transport surface 18. The sensor 20 detects and outputs the distance to the upper surface of the printing paper 2 on the transport surface 18.
[0027]
The distance from the sensor 20 to the transport surface 18 is predetermined and constant. The value is stored in the control means 30. Further, the distance between the sensor 20 detected by the sensor 20 and the upper surface of the printing paper 2 is input to the control means 30. When the printing paper 2 is warped upward, that is, when it is convex upward in the cross section orthogonal to the conveyance direction, the distance between the sensor 20 and the conveyance surface 18 is the distance between the sensor 20 and the printing paper 2. Bigger than. The difference between the two distances indicates the amount of warping of the printing paper 2. The control means 30 calculates the amount of warping of the printing paper 2 from the distance between the sensor 20 and the transport surface 18 and the distance between the sensor 20 and the printing paper 2 detected by the sensor 20. Then, the control means 30 drives the elevating motor 5 via the motor drive 31 based on the calculated amount of warpage of the printing paper 2 and moves the conveying means 11. That is, if the upper half of the belt 13 of the transport unit 11 is within the transport surface 18, the transport unit 11 is raised by the amount of warpage of the printing paper 2. If the upper half of the belt 13 of the transport unit 11 is already above the transport surface 18, the transport unit 11 is raised to a position where the upper half of the belt 13 of the transport unit 11 contacts the lower surface of the printing paper 2.
[0028]
The sensor 20 is a generally used distance measuring sensor including a light emitting unit and a light receiving unit. The distance from the light emitting unit to the center of the light receiving unit is fixed. The light emitted from the light emitting part is reflected by the surface of the printing paper and received at any position in the light receiving part. The reflection angle of light on the surface of the printing paper is determined by the received position. From this reflection angle, the distance between the printing paper and the light emitting portion is obtained.
[0029]
The sheet conveying apparatus 1 of this example can convey the flat undeformed printing paper 2 as well as printing in which the shape in the cross section perpendicular to the conveying direction is convex as shown in FIG. Even the paper 2 can be conveyed. This is the most different point from the conventional transfer device. Therefore, the conveying apparatus of the present example exhibits a particularly remarkable effect when applied to the sheet processing means for discharging the deformed sheet. For example, as in this example, in a printing apparatus that prints with ink on the upper surface of a sheet, the printing paper 2 is deformed so as to be convex upward in a cross section orthogonal to the transport direction. Providing the sheet conveying apparatus 1 of the present example is effective in that it is possible to prevent a conveyance defect that tends to occur in the past. In addition, examples of the sheet processing apparatus that causes the sheet to undergo such deformation include a laminating apparatus, a photographic processing apparatus, a printer of various principles, and a PPC.
[0030]
The operation of the above configuration will be described.
The printing paper 2 printed by the printing apparatus enters the conveyance guide 15 and is placed on the conveyance surface 18. When the printing paper 2 is bent upward, it cannot be transported because the transport belt 13 is in the transport surface 18 as shown in FIG. In this example, the sensor 20 detects the upper surface of the printing paper 2, and the control means 30 determines the amount of warping of the printing paper 2. Then, the control means 30 raises the conveying means 11 in accordance with the determined warpage amount, so that the belt 13 of the conveying means 11 can contact the lower surface of the printing paper 2 above the conveying surface 18 as shown in FIG. The belt 13 driven by the conveyance motor 14 conveys the printing paper 2.
[0031]
When a series of printing sheets 2 on which the same image is printed are successively sent out from the printing apparatus, the amount of warping of the first sheet may be measured to set the position of the transport unit 11. This is because if the printing conditions are the same, the warping amounts of the second and subsequent printing papers 2 are considered to be substantially the same. The printing paper 2 is sequentially stored in the paper discharge device 101 described above.
[0032]
Although the conveying means 11 of this example has the pulley 12 and the belt 13, it may be constituted by a plurality of rollers.
[0033]
In the example described above, the transport unit 11 is moved by the lifting motor 5 and is set at a position above the transport surface 18 according to the amount of warpage of the printing paper 2 detected by the sensor 20. However, if the amount of warpage of the sheet to be conveyed is constant and can be expected, the elevating means and sensors of the conveying means are not necessarily required. That is, the conveying means is fixed at a predetermined height from the conveying surface in accordance with the assumed amount of warping of the sheet. The configuration of the sheet conveying apparatus in this case is substantially the same as that in FIG. Of course, in this case, since the transport unit 11 is fixed at a position above the transport surface 18, it is not possible to transport a sheet having a warp amount larger than the assumed warp amount. However, a sheet having a smaller amount of warpage than the assumed amount of warpage or a flat sheet that is not warped can be conveyed.
[0034]
【The invention's effect】
According to the first aspect of the present invention, since the conveying means is set above the conveying surface in accordance with the amount of warping of the sheet to be conveyed, even a warped sheet can be conveyed without any trouble.
[0035]
According to the second aspect of the present invention, the conveying unit can be moved up and down with respect to the sheet conveying surface, and the position of the sheet on the raising and lowering surface is detected by the detecting unit, and the conveying unit is moved accordingly. Is set in contact with the lower surface of the sheet to give a reliable conveying force to the sheet. Therefore, according to the present invention, there is an effect that the sheet can be reliably conveyed even if the sheet has a convex shape in a cross section perpendicular to the conveyance direction.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of the present invention viewed from a vertical plane parallel to a printing paper conveyance direction.
FIG. 2 is a side view of the embodiment of the present invention viewed from a vertical plane orthogonal to the conveyance direction of the printing paper.
FIG. 3 is a side view of the embodiment of the present invention viewed from a vertical plane orthogonal to the conveyance direction of the printing paper.
FIG. 4 is a perspective view of a paper discharge device provided with a conventional transport device.
FIG. 5 is a diagram illustrating a main part of a paper discharge device.
FIG. 6 is a perspective view of a part of a conventional transport device and a paper discharge device.
FIG. 7 is a side view of a conventional transport device viewed from a vertical plane orthogonal to the transport direction of printing paper.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sheet conveying apparatus 2 Printing paper 5 as sheet | seat 5 Elevating / lowering motor 8 as raising / lowering means 8 Support stand 11 Conveying means 12 Pulley 13 Belt 16 Opening 18 Conveying surface 20 Sensor 30 as detection means Control means

Claims (7)

A conveyance surface for conveying a sheet;
A lower surface of the sheet on the conveying surface, and conveyance means in contact with the central portion in the direction perpendicular to the conveying direction of the sheet you conveying said sheet,
Elevating means for elevating and lowering the conveying means so that a portion in contact with the lower surface of the sheet moves at least between a position in the conveying surface and a position above the conveying surface;
Detecting means for detecting a position of a central portion in a direction orthogonal to a conveying direction of the sheet to be conveyed;
A sheet conveying apparatus comprising: a control unit that controls the elevating unit so that the conveying unit moves upward from a position in the conveying surface according to the position of the sheet detected by the detecting unit. A conveyance surface for conveying a sheet;
Conveying means for conveying the sheet in contact with the lower surface of the sheet on the conveying surface;
Elevating means for elevating and lowering the conveying means so that a portion in contact with the lower surface of the sheet moves at least between a position in the conveying surface and a position above the conveying surface;
Detecting means for detecting the position of the conveyed sheet;
In the sheet conveying apparatus , comprising: a control unit that controls the elevating unit so that the conveying unit moves upward from a position in the conveying surface according to the position of the sheet detected by the detecting unit .
The detection means is a sensor that is provided above the conveyance surface and detects and outputs a distance to the upper surface of the sheet on the conveyance surface;
The control means calculates the amount of warping of the sheet from the difference between the distance from the sensor to the conveyance surface and the distance from the sensor detected by the sensor to the upper surface of the sheet, The sheet conveying apparatus , wherein the elevating means is controlled so that a portion in contact with the lower surface moves upward from a position in the conveying surface by a distance equal to or more than the warpage amount . In the conveyance surface, an opening is formed in the center along the conveyance direction of the sheet,
The sheet conveying apparatus according to claim 2 , wherein the conveying unit is provided in the opening. The transport means includes a support base, a pair of pulleys provided on the support base, and a belt wound around the pair of pulleys,
The sheet conveying apparatus according to claim 3 , wherein the elevating unit elevates and lowers the support base so that the upper side of the belt can move between a position in the opening in the conveying surface and a position above the position. . The sheet according to claim 1 or 2 Symbol placement of the sheet conveying device in the form of upwardly convex in a cross section perpendicular to the conveying direction. Claim 1 or 2 Symbol placement of the sheet conveying apparatus is applied to a sheet processing means for discharging the sheet in the shape of an upwardly convex in a cross section perpendicular to the conveying direction. The sheet conveying apparatus according to claim 6 , wherein the sheet processing unit is a printing apparatus that performs printing on the upper surface of the sheet with ink.

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