JP4395587B2 - Sheet conveying device - Google Patents

Description

  The present invention relates to a sheet conveying apparatus that conveys a sheet in close contact with an inspection cylinder while further tensioning the sheet by holding units that hold both front and rear ends of the sheet in the inspection apparatus.

  Conventionally, in the inspection of a sheet using an inspection cylinder, a holding device constituted by a gripper first holds the front end of the sheet, and then the vacuum pump sucks air from the suction hole on the surface of the inspection cylinder connected to the vacuum pump. Thus, a method in which the sheet is brought into close contact with the inspection cylinder and passed through the imaging area of the inspection imaging apparatus has been generally used. However, in this case, since the sheet floats or flutters from the surface of the inspection cylinder during the rotation of the inspection cylinder, high-precision inspection is impossible.

  Therefore, in order to solve the above problems, in the printed matter inspection apparatus installed in the sheet-fed printing press, a plurality of paper pressing rollers are moved to and positioned at arbitrary positions, and the passage timing of the sheet to be inspected is passed. In response to the above, there has been proposed a printed matter inspection apparatus equipped with a paper pressing device that presses the paper pressing roller onto the final impression cylinder and positions the paper pressing roller with a graphic display (for example, see Patent Documents 1 and 2). .).

  In particular, when the paper is thin paper, if the suction head is moved in the groove in order to bring the paper sucked by the suction head into close contact with the cylinder circumferential surface, the paper is recessed at the corresponding portion of the groove and the whole paper is slightly extended. As a result, in the case of reverse printing, in order to solve the problem that printing registration failure occurs in reverse side printing, one end of the belt-like leaf spring is fixed to the paper holding member that holds the paper bottom, and this leaf spring is There is provided a paper bottom holding device for a grooved cylinder in a printing press in which a tension spring force is applied to the leaf spring by being in contact with a step at the opening end in the groove so as to have the same radius as the peripheral surface. It has been proposed (see, for example, Patent Document 3).

  In addition, an air blowing device is provided to face the inspection cylinder so that the printed sheet is in close contact with the inspection cylinder. However, according to the air blowing apparatus, when the inspection apparatus is inspected at high speed, the printed matter is printed. The air blowing time is relatively short, so that there is a problem that the air between the printed material and the inspection cylinder does not sufficiently escape and the printed material cannot be in close contact with the inspection cylinder. There has been proposed a printed material contact apparatus improved by providing a plurality of air intake holes on the peripheral surface of the material and sucking the printed material from the air intake holes so that the printed material is held in close contact with the inspection cylinder (see, for example, Patent Document 4).

  Further, as shown in FIG. 3, a segment (13) having a gripper type front end holding device (11) for holding the front end of the sheet (7) on the rotating shaft and an air adsorption type for holding the rear end of the sheet by an air adsorption member. The segments (14) having the rear end holding device (12) are joined, and each segment is shaped to form one arc when viewed from the axial direction, and is connected to each other in a comb shape in the axial direction. There is known an inspection apparatus provided with a drum that rotates in the C and D directions with respect to the circumferential direction so that both segments tension the sheet before the sheet is inspected (see, for example, Patent Document 5). .). However, in this case, the peripheral surface of the comb-like segments connected in the axial direction is not uniform, and the optical state of the surface to be inspected of the sheet is not uniform due to the height difference and gap generated between the segments, As a result, it is difficult to increase the inspection accuracy even if the performance of the inspection imaging apparatus is increased.

Japanese Examined Patent Publication No. 4-12228 Japanese Patent Publication No. 4-21589 Japanese Patent No. 2559043 Japanese Utility Model Publication No. 2596839 JP-T-2001-509746

  In recent years, inspection apparatuses that detect defects such as misregistration of printed sheets, variations in color density, and dirt have become increasingly sophisticated, and the demand for detection of minute defects has increased.

  In addition, there is a case where glossy ink is used for printing or a hologram used as an anti-counterfeit device is attached to a sheet, and the demand for these inspections is rapidly increasing.

  However, since these sheets change the image obtained from the imaging device significantly due to slight variations in the illumination method, the state of the sheet, and the imaging method, In order to accurately determine the damage, it is necessary to keep the optical conditions of the sheet, the illuminating device, and the sheet, and the imaging device constant while keeping the sheet uniformly tensioned while the sheet passes through the imaging area of the imaging device. In the conventional transfer apparatus, it is difficult to guarantee these points due to the above-described problems.

  Accordingly, an object of the present invention is to maintain the optical state of the surface to be inspected of the printed sheet uniformly and to improve the inspection accuracy of the forgery prevention device, so that the front end of the sheet passed from the transfer cylinder to the inspection cylinder And an inspection cylinder having a mechanism for holding the rear end and adsorbing air to the surface of the inspection cylinder. After holding the sheet by these two holding parts, the surface of the inspection cylinder is operated so that both holding parts operate to pull the sheet. It is to provide a transport device and a transport method for transporting a sheet so that the sheet is brought into close contact with an inspection cylinder by air adsorption and no floating or flapping occurs.

  The conveying device for conveying a sheet according to the present invention is a conveying device in which an imaging device for inspection is provided in an inspection unit of an inspection device, and the sheet is conveyed in close contact with the surface of an inspection cylinder while holding the front end of the sheet A front end holding part provided on the inspection cylinder, and a rear end holding part provided on the inspection cylinder holding the rear end of the sheet. The front end holding part is the front end of the sheet, and the rear end holding part is the rear end of the sheet. It is characterized by having a mechanism for tensioning the end while holding the sheet.

  The conveying apparatus for conveying a sheet according to the present invention is characterized in that the front end holding part is a gripper type front end holding part and the rear end holding part is an air adsorption type rear end holding part.

  In addition, the conveyance device for conveying a sheet according to the present invention is configured so that the tension mechanism of the front end holding unit holds the front end of the sheet while the front end of the sheet passes through the inspection imaging device, and the front end holding unit is placed inside the inspection cylinder. This is a retractable movable mechanism having a mechanism that moves toward the front, and the tension mechanism of the rear end holding portion is a rotation mechanism that rotates in a direction opposite to the rotation direction of the inspection cylinder while holding the rear end of the sheet. .

  In addition, the conveyance device for conveying a sheet according to the present invention is characterized in that an air adsorbing type center holding portion for air adsorbing the center portion of the sheet to the inspection cylinder is provided between the front end holding portion and the rear end holding portion. .

According to the present invention, there is an inspection cylinder having a mechanism for holding the front end and the rear end of the sheet, and since the sheet is held in a tensioned state by the two holding portions, there is a gap between the sheet and the inspection cylinder. Since it adheres uniformly to the inspection cylinder without causing any flickering or flapping, the optical state of the sheet surface can pass through the imaging area of the inspection imaging device without changing. Therefore, it is possible to improve the inspection accuracy of the sheet by the inspection device and to increase the efficiency of the inspection process.

  Hereinafter, the present invention will be described in detail based on embodiments of the present invention with reference to the drawings. FIG. 1 is a schematic view of an inspection cylinder having two holding portions according to an embodiment of the present invention. A driving method of the holding device may be either a pneumatic method or a cam type. An explanation will be given using a pneumatic system (not shown) in which an air cylinder is operated at a certain timing while detecting a phase by a rotary encoder which is the above technique.

In this embodiment, the inspection cylinder (4) is provided with a gripper type front end holding part (1), an air suction type central holding part (2) and an air suction type rear end holding part (3), and the gripper type front end holding part. The part (1) has a retractable moving mechanism that moves in the A direction toward the central axis of the inspection cylinder, and the air adsorption rear end holding part (3) has a rotating mechanism that rotates in the B direction.
In addition, there are air adsorption, electrostatic adsorption, and the like in the adsorption, but air adsorption can be tensioned while directly contacting the paper as compared with electrostatic adsorption, and therefore air adsorption is used in this embodiment.

  FIG. 2 shows a schematic diagram of the inspection apparatus in the present embodiment. An imaging device for inspection is provided on a support through the frame of the inspection unit of the inspection device, and the sheet (7) conveyed from the paper supply plate of the paper supply unit is transferred from the swing device (8) to the transfer cylinder (9). (4) Hold the front end of the sheet with the gripper type front end holding part (1) when switching to the front, and hold the center part of the sheet with the air adsorption center holding part (2) as the inspection cylinder (4) rotates Finally, the trailing edge of the sheet is held by the air adsorption type trailing edge holder (3).

  Thereafter, the gripper type front end holding portion (1) moves in the A direction toward the central axis of the inspection cylinder, and the air adsorption type rear end holding portion (3) rotates in the B direction, whereby the sheet (7 ) Hold in tension.

  Finally, this state is maintained until the sheet (7) passes through the imaging area of the inspection imaging device (10), after which the gripper of the gripper type front end holding part (1) opens and the next transfer cylinder is opened. After changing the sheet to (10), the sheet is conveyed to a paper discharge unit and sorted into a damage pile or a sampling pile according to a determination result of a determination unit (not shown).

The schematic diagram of the inspection cylinder which has two holding parts concerning one embodiment of the present invention is shown. The schematic diagram of the inspection device provided with the inspection cylinder which has two holding parts concerning one embodiment of the present invention is shown. 1 shows a schematic diagram of a drum having a conventional holding device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gripper type front end holding part 2 Air adsorption type center holding part 3 Air adsorption type rear end holding part 4 Inspection cylinder 5 Inspection imaging device 6 Illumination 7 Sheet 8 Swing apparatus 9, 10 Transfer cylinder 11 Gripper type front end holding apparatus 12 Air adsorption Rear end holding device 13, 14 segments

Claims (3)

An inspection imaging apparatus is provided in the inspection unit of the inspection apparatus, and the sheet is transported in close contact with the surface of the inspection cylinder while being in tension,
A front end holding portion provided in the inspection cylinder for holding the front end of the sheet;
A rear end holding portion provided in the inspection cylinder for holding the rear end of the sheet,
The front end holding unit includes a tension mechanism that tensions the front end of the sheet, and the rear end holding unit tensions the rear end of the sheet while holding the sheet ,
The tension mechanism of the front end holding portion has a mechanism in which the front end holding portion moves toward the inside of the inspection cylinder before the front end of the sheet passes through the inspection imaging device while holding the front end of the sheet. Retractable moving mechanism,
The sheet conveying apparatus according to claim 1, wherein the tension mechanism of the trailing edge holding portion is a rotating mechanism that rotates in a direction opposite to the rotation direction of the inspection cylinder while holding the trailing edge of the sheet.   2. The sheet conveying apparatus according to claim 1, wherein the front end holding portion is a gripper type front end holding portion, and the rear end holding portion is an air adsorption type rear end holding portion.   3. The inspection cylinder is provided with an air adsorbing type center holding portion for air adsorbing the center portion of the sheet between the front end holding portion and the rear end holding portion. Sheet transport device.

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