JP5011418B2 - Inspection sheet transport device - Google Patents

Description

  The present invention relates to an inspection sheet conveying apparatus that inspects and conveys a sheet of sheet such as paper or film while being held flat.

In recent years, along with the demand for high-quality thinking on the print quality of sheets, a production method has been adopted in which quality inspection is performed through an image camera to identify defects such as scratches, dirt, misalignment, and color unevenness by computer processing. It's getting on.
This quality inspection not only checks the print quality, but also checks for defects in the white paper before printing, leading to other coated paper such as paper irregularities, perforations, wrinkles, tears, insect jumps, etc. that may have occurred during the manufacturing process. Detects streaks and the like.
In the prior art, the sheets fed continuously from the sheet feeding unit are regulated in the front / rear / left / right positions by a registration device upstream of the inspection sheet transport apparatus, and then placed on the inspection sheet transport apparatus. Passes below the inspection camera line at a high speed of about 150 m / min, and at the time of passing, the quality of the sheet is instantaneously determined, and a signal from the inspection camera side downstream of the inspection sheet transport device In the output, a good sheet and a bad sheet are sorted, and are divided into a good sheet storage unit and a defective sheet storage unit.
In the inspection sheet transport apparatus, the upper and lower sides of the sheet are moved until the leading edge of the sheet passes through the width direction of the sheet being transported and below the line of sight of the inspection camera until the trailing edge has passed. Inspection accuracy by the inspection camera deteriorates even if there is a slight flickering, unevenness, front / rear / left / right, or oblique displacement.
As a prior art, as shown in FIGS. 4 and 5, a fixed plate provided with a number of suction holes, a mesh-like conveyor belt that moves on the fixed plate and attaches a sheet of paper, and the fixed plate Japanese Patent Application Laid-Open No. 2005-231756 discloses a sheet-like material conveying device that uses a suction fan 16 to suck and fix a conveyed sheet onto a mesh-like conveying belt.
When inspecting using the inspection sheet transport apparatus, the transport sheet is sucked and fixed onto the mesh transport belt by the suction fan 16. The suction force of the suction fan 16 is not uniform at the center and corners of the net-like transport belt, and it is inevitable that the transported sheet is sucked with a non-uniform suction force.
As a result, when the rotation of the suction fan 16 is increased in order to suppress the fluttering of the upper and lower sides of the sheet, a part of the sheet is disadvantageously caused to have irregularities due to being sucked into the mesh transport belt. Unevenness due to belt seams is inevitable. However, if the suction force of the belt is set to be weak, a defect of flapping of the sheet occurs. Further, if the sheet is weakly sucked onto the reticulated conveyance belt, the accurate vertical position of the surface of the sheet is shifted and the inspection accuracy is lowered.
In addition, it is necessary to prevent a decrease in inspection accuracy due to the lateral deviation of the sheet due to the meandering that always exists in the belt.

JP 2005-231756 A

  An object of the present invention is to eliminate the disadvantage of accuracy reduction at the time of camera inspection due to unevenness of a sheet caused by sheet suction to an endless mesh belt of an inspection sheet transport device. An object of the present invention is to provide a highly accurate sheet transport apparatus for inspection.

In the inspection sheet transport apparatus according to the present invention, the sheet being transported is free from vertical flutter, unevenness, front / rear left / right, and oblique positional deviation especially in the detection unit of the inspection camera 15, and the inspection camera. Precise flatness is required to be maintained until the end of the paper passes through the 15 detectors.
As a result of diligent research, the inventor has inspected a sheet of paper by using the fixing plate 4 provided with a number of suction holes and the endless mesh belt 8 sliding on the fixing plate 4 of the prior art (Patent Document 1) of the present invention. By improving the air suction method of the technical configuration in which air suction from below the fixed plate 4 is applied to the process, it is possible to maintain a precise flatness until the end of the paper passes through the detection unit of the camera. The present invention was completed by finding out what can be done.
The improvement of the air suction method of the present invention is that the prior art air suction method is simply suctioning the entire lower surface of the fixed plate 4 by a fan, whereas the present invention is directed to the entire lower surface of the fixed plate 4. It has been found that air can be sucked from the lower surface of the endless mesh belt 8 with a precisely controlled uniform and stable suction force by changing the fan system from a fan system to a fan system with a suction tank. It was possible to completely suppress the flutter of the entire sheet. Then, a two-stage suction means for maintaining the exact flatness of the inspection portion is obtained by sucking the air at the position of the camera's line of view through a pin-point suction duct, particularly by a ring blower or a vacuum pump. By applying this method, it is characterized in that accurate flatness of the inspection portion is ensured, the unevenness caused by the air suction of the fan is prevented, and the upper and lower fluctuations of the paper are suppressed.
That is, the present invention
(1) A sheet transport apparatus for inspection used in a sheet inspection apparatus, comprising an inspection camera at the top, a drive roller and a driven roller that rotate on a pair of horizontal parallel shafts, and the pair of rollers An endless mesh that stretches around the back surface in contact with the back surface, reaches from the top surface of the driven roller to the top surface of the drive roller, rotates around the roll surface of the drive roller, and is connected from the bottom surface of the drive roller to the bottom surface of the driven roller comprising a belt, from the top surface of the driven roller, and the back surface of the endless mesh belt moving on the upper surface of the drive roller is a plate surface that slides, has a fixed plate having a plurality of air suction holes as on the surface, below the has a suction tank having a discharge fan to the opening, the suction tank, perpendicular the Waist and the endless mesh belt intersects the position of the upper surface of that with respect to the running direction of the endless mesh belt It provided inside the suction tank across, and sucks the pinpoint suction duct and the pinpoint suction duct having a plurality of air suction holes with the surface to form a fixing plate surface and the step is not a flat surface of the Aspirate tank A sheet conveying device for inspection, characterized by having a ring blower or a vacuum pump;
(2) A sheet conveying apparatus for inspection as set forth in (1), wherein the pinpoint suction duct is integrally fixed inside a suction tank having a fixed plate having a number of air suction holes as an upper surface. as well as,
(3) The endless mesh belt used for conveyance is stretched between a driving roller and a driven roller, and a pair of ridges extending in the running direction of the endless mesh belt are provided on the left and right sides of the endless mesh belt. In addition, the inspection sheet according to (1) or (2), wherein an engagement groove is provided on the peripheral surfaces of the drive roller and the driven roller to engage with the convex body of the endless mesh belt. A conveying device is provided.

  The two-stage suction means of the general suction of the fixed plate 4 by the vacuum suction tank of the present invention and the strong suction of the detection part of the camera by the pinpoint suction method prevents the formation of irregularities on the paper surface and the sheet. It is possible to suppress fluttering and fluttering, and to maintain a precise flatness until the end of the sheet passes through the detection part of the inspection camera 15 so that the sheet can be stably and accurately inspected. it can.

It is a top view of the Example of the sheet transport apparatus for a test | inspection of this invention. It is sectional drawing of the Example of the sheet transport apparatus for a test | inspection of this invention. It is sectional drawing of the endless mesh belt used for the sheet conveying apparatus for a test | inspection of this invention. It is a top view of an example of the conventional sheet transport apparatus for inspection. It is sectional drawing of an example of the conventional sheet transport apparatus for a test | inspection.

Hereinafter, it explains in detail using a drawing.
FIG. 1 is a plan view of an embodiment of an inspection sheet conveying apparatus according to the present invention, and FIG. 2 is a sectional view of the apparatus of FIG. In FIG. 1, the camera and the fluorescent lamp for the light source are omitted. FIG. 3 is a sectional view of the endless mesh belt 8 used in FIG. 1 cut vertically.
The inspection sheet conveying apparatus is provided with a pair of left and right frames 1 erected so as to face each other. These frames 1 are provided with two pairs of shaft insertion holes 2 that face each other. Corresponding to these shaft insertion holes 2, bearings 3 are respectively attached to the outer surfaces of the left and right frames 1 by screws.
The fixed plate 4 is formed in a rectangular shape by a metal flat plate. A large number of air suction holes 5 are formed uniformly over the entire surface. The fixed plate 4 is attached to the left and right frames 1 via brackets so as to be positioned between the driving roller 6 and the driven roller 7.
The endless mesh belt 8 is formed in an endless shape, the width in the left-right direction is slightly smaller than the width of the fixed plate 4, and the driving roller 6 and the driven roller 7 are arranged so as to contact the fixed plate 4. It is stretched between. This endless mesh belt 8 is formed in a mesh shape of about 15 to 50 mesh / inch by using a polyester having a small thickness and a small rigidity. As shown in FIG. Convex ribs 9 are integrally projected in parallel with the traveling direction. Since the endless mesh belt 8 circulates while the protruding ribs 9 are fitted in the engagement grooves 10 of the driving roller 6 and the driven roller 7, the lateral displacement of the printing surface due to the meandering rotation of the endless mesh belt 8 is eliminated. Accurate inspection can be performed.
A suction tank 11 having a fixed plate 4 having a number of air suction holes 5 as an upper surface is installed on the lower surface of an endless mesh belt 8 that travels with a sheet of paper from the driven roller 7 to the drive roller 6. The suction tank 11 is moderately depressurized by a vacuum pump. Unlike the suction by the fan, the suction by the axial fan 17 through the suction tank 11 can suck the lower surface of the endless mesh belt 8 uniformly. Therefore, the sheet is stably held on the endless mesh belt 8 that moves at a high speed even when the degree of decompression is relatively weak so that the unevenness of the sheet does not occur.
The endless mesh belt 8 that travels at a high speed on the fixed plate 4 slides on the surface of the fixed plate 4 having a large number of air suction holes 5 in the suction tank 11 so that the entire surface of the sheet is sucked and fixed uniformly. The fluttering of the sheet can be completely suppressed. However, if the degree of decompression of the suction tank 11 is set to be large, the sheet is sucked into the air suction hole 5 to form fine concave portions on the paper surface, and the inspection accuracy is lowered. The suction tank 11 is preferably set in the internal space of the upper and lower endless mesh belts 8 that run in the reverse direction. However, as shown in FIG. 2, the suction tank 11 runs endlessly in the suction tank 11 from the driving roller 6 to the driven roller 7. The mesh belt 8 can also be passed. In this case, the degree of vacuum is reduced, but the uniformity at a low degree of vacuum is still maintained.

As shown in FIG. 2, a fluorescent lamp 14 and an inspection camera 15 which are light sources are installed on the upper part of the inspection sheet conveying apparatus. A pinpoint suction duct 13 is provided at a position where the camera line of sight 12 on the upper surface of the suction tank 11 of the inspection sheet conveying apparatus vertically crosses the lateral width of the suction tank 11.
The upper surface of the pin-point the suction duct 13 has a plurality of air Aspirate perforated surface forming a fixed plate 4 faces and the step is not a flat surface of the Aspirate tank. As a result, the suction force is increased in a narrow area at the position of the camera line of sight 12, and suction is performed stably and reliably, and accurate flatness of the sheet surface is obtained.
A discharge axial fan 17 for generating strong wind power is provided at the opening below the suction tank 11 to discharge the air in the suction tank. Since the suction tank 11 is interposed, the suction force of the axial fan 17 that performs powerful discharge is weakened, and the suction force related to the upper surface of the suction tank 11 can be made uniform over the entire surface.
A ring blower or a vacuum pump (not shown) is connected to the pinpoint suction duct 13 so that the interior of the pinpoint suction duct 13 can be maintained under a reduced pressure stronger than that of the suction tank 11. The degree of decompression of the pinpoint suction duct 13 can be automatically controlled in conjunction with the pressure gauge.
With this configuration, the driving roller 6 is driven to run the endless mesh belt 8, and the sheet is fed onto the endless mesh belt 8 with suction being activated. Since air staying above the endless mesh belt 8 is sucked between the endless mesh belt 8 and through the suction holes of the fixed plate 4 and below the fixed plate 4, the air stays on the surface of the endless mesh belt 8. The attached sheet is adsorbed on the surface of the endless mesh belt 8. Accordingly, the sheet follows the traveling of the endless mesh belt 8 and is conveyed so as to contact the surface of the fixed plate 4. While being conveyed, the quality of the printed surface of the sheet and the quality of the paper itself are inspected by the camera.
Since the endless mesh belt 8 is used as the conveying belt, the amount of suction air passing through the endless mesh belt 8 increases, so that the sheet is adsorbed to the endless mesh belt 8 with good adhesion.
The suction of air to the entire lower surface of the fixed plate 4 is suction from the fan through the suction tank, and the suction of air at the position of the camera line of sight 12 is performed by the pinpoint suction duct 13 by the ring blower. By applying a two-stage suction means that sucks strongly, unevenness of the sheet caused by air suction can be prevented.
In the apparatus of the present invention, the sheet can be transported in a flat state without any unevenness, and the inspection by the camera can be performed stably and accurately.

  The inspection sheet conveying apparatus of the present invention is disposed in a printing machine or the like and is useful in the paper machine field such as printing quality inspection, defect inspection of blank paper before printing, inspection of defects generated in the manufacturing process, and the like.

DESCRIPTION OF SYMBOLS 1 Frame 2 Shaft insertion hole 3 Bearing 4 Fixing plate 5 Air suction hole 6 Driving roller 7 Driven roller 8 Endless mesh belt 9 Convex rib 10 Engaging groove 11 Suction tank 12 Camera line of view 13 Pinpoint suction duct 14 Fluorescent lamp 15 Inspection Camera 16 Suction fan 17 Axial fan

Claims (3)

An inspection sheet transport apparatus used in a sheet inspection apparatus, comprising an inspection camera at the top, a pair of driving rollers and a driven roller that rotate on a horizontal parallel axis, and the back side of the pair of rollers are circulating freely stretched in contact, from the upper surface of the driven roller, it reaches the upper surface of the drive roller, around the roll surface of the drive roller, from the lower surface of the drive roller, comprising an endless mesh belt is connected to the lower surface of the driven roller The plate surface on which the back surface of the endless mesh belt that moves from the upper surface of the driven roller to the upper surface of the drive roller slides, has a fixed plate having a number of air suction holes as the upper surface, and has a lower opening. has a suction tank having a discharge fan, the suction tank is transected vertically the Waist and the endless mesh belt intersects the position of the upper surface of that with respect to the running direction of the endless mesh belt Ring blower for sucking pinpoint suction duct and the pinpoint suction duct having a plurality of air suction holes with a surface provided inside, and forms a fixing plate surface and the step is not a flat surface of the suction tank of the suction tank as Alternatively, an inspection sheet conveying apparatus having a vacuum pump.   2. A sheet conveying apparatus for inspection according to claim 1, wherein the pinpoint suction duct is integrally fixed inside a suction tank having a fixed plate having a number of air suction holes as an upper surface. The endless mesh belt used for conveyance is stretched between a driving roller and a driven roller, and a pair of ridges extending in the traveling direction of the endless mesh belt are provided on the left and right sides of the endless mesh belt, 3. The inspection sheet conveying apparatus according to claim 1, wherein an engagement groove is provided on the peripheral surfaces of the driving roller and the driven roller to engage with the protrusions of the endless mesh belt.

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