JP4218030B2 - Sheet shape measuring method and apparatus - Google Patents

Description

  The present invention relates to a sheet shape measuring method and apparatus, and more particularly to a sheet shape measuring method and apparatus for measuring on-line the shape of a lithographic printing plate in which slip sheets are laminated as a sheet with an optical measuring instrument.

  In recent plate making methods (including electrophotographic plate making methods), lithographic printing plates such as photosensitive printing plates and heat-sensitive printing plates are widely used in order to facilitate automation of the plate making process. Production of a lithographic printing plate is generally performed on a support such as a sheet-like or coil-like aluminum plate, for example, graining, anodizing, silicate treatment, other surface treatment such as chemical conversion treatment alone or in combination, and then, A coating film for forming a photosensitive layer or a heat-sensitive layer (hereinafter referred to as a printing surface) is applied and dried to produce an original sheet of a lithographic printing plate, which is once wound on a winder. Next, the raw material is rewound from the winder and sent to the sheet processing step. After being cut into a predetermined slit width by a slitter in the sheet processing step, it is cut into a predetermined cut length by a running cutter. Thereby, a rectangular sheet-like planographic printing plate is manufactured.

  In this sheet processing process, in order to guarantee the product size of the cut lithographic printing plate, the lithographic printing plate is sampled after being cut into a sheet, and the shape of the lithographic printing plate, for example, the product size (slit Width, cut length, squareness) are measured to guarantee the size of the planographic printing plate. In addition to requiring the man-hours of the operator for this offline inspection, if a size abnormality is discovered by the offline inspection, it is necessary to inspect all the lithographic printing plates cut by the end of the inspection. If all the products are abnormal in size by 100% inspection, a large number of planographic printing plates will result in product loss, resulting in great damage.

  Also, in recent years, the introduction of online measuring equipment that automates various visual inspections and performs online measurement in real time, while increasing the speed of sheet processing, darkening digital varieties, and reducing labor for operators. It has been demanded.

  As an apparatus for measuring a sheet-like object on-line, for example, as disclosed in Patent Document 1 and Patent Document 2, the sheet size is measured by irradiating the sheet with light and detecting the reflected light with a CCD camera. Optical on-line measuring devices have been proposed.

  Since this optical on-line measuring device captures the reflected light with a CCD camera, a sheet guide mechanism is required to keep the distance of the sheet to the CCD camera constant so that the image data does not become out of focus. is there. Thus, when measuring a sheet optically, it is important not only for the devices of Patent Document 1 and Patent Document 2 but to keep the distance of the sheet to the measuring device constant to improve the measurement accuracy. It is.

As a sheet guide mechanism of an apparatus for optically inspecting a sheet-like object, a sheet guide mechanism for maintaining a constant distance from an image scanner (sensor) to a sheet (for example, thin paper, a passbook) has been proposed ( Patent Document 3). This guide mechanism is composed of a leaf spring in which the guide body and the base end side are fixed and the tip end side is in contact with the guide body, and the sheet conveyed by the conveying roller moves while sliding on the guide body of the guide mechanism. To do. At this time, the front end side of the leaf spring is deformed downward according to the thickness of the sheet, the elastic repulsion force of the leaf spring due to the deformation and the weight of the sheet balance, and the distance between the upper surface of the sheet and the sensor becomes substantially constant. I am doing so. Thereby, since the distance from the sensor to the sheet is substantially constant, the measurement accuracy can be improved.
JP-A-5-52526 Japanese Patent Laid-Open No. 6-147836 JP 2003-212383 A

However, even if the guide mechanism of Patent Document 3 is applied to a lithographic printing plate that has a printing surface (photosensitive layer surface or heat-sensitive layer surface) that is liable to be damaged due to scratches and is not flat due to curl or the like, high-precision measurement is possible. Cannot be performed, and the printed surface is damaged. To elaborate on this point,
(1) As explained in the prior art, the planographic printing plate has a roll-shaped support or curl originating from the original fabric, and the distance of the planographic printing plate to the optical measuring instrument is not constant. Therefore, an apparatus for measuring the shape of a lithographic printing plate must be able to measure the shape of the lithographic printing plate so that the distance from the measuring device can be kept constant regardless of the difference in curl and the printing surface is not damaged. .
(2) The lithographic printing plate has minute irregularities in addition to the curl, and due to the difference in the minute irregularities, the position of the lithographic printing plate with respect to the optical measuring instrument is not constant. Therefore, an apparatus for measuring the shape of a lithographic printing plate must be able to measure the shape of the lithographic printing plate so that the distance from the measuring device can be kept constant regardless of the difference in micro unevenness and the printing surface is not damaged. .
(3) The optical shape of the lithographic printing plate is measured by irradiating the lithographic printing plate with light when the lithographic printing plate is transferred from the upstream conveyor to the downstream conveyor. The amount of sag due to the weight of the planographic printing plate varies depending on the thickness. Therefore, since the distance of the lithographic printing plate to the measuring instrument is not constant, a guide mechanism is required so that the lithographic printing plate does not hang down at the measurement position.
(4) When the printing surface of the lithographic printing plate is a photosensitive layer, there is a concern about the quality failure due to fogging, and therefore it cannot be measured by irradiating the photosensitive layer with the light beam of a measuring instrument. Therefore, it is necessary to measure with the measuring device disposed on the side opposite to the photosensitive layer. In this case, in the guide mechanism of Patent Document 3, the photosensitive layer faces the guide body and the planographic printing plate slides. The photosensitive layer is rubbed and damaged by the guide body. This is because the guide mechanism of Patent Document 3 cannot be used for a sheet that is not flat and has a problem of quality failure with respect to scratches and light beams for measurement other than in the case of a lithographic printing plate. It is necessary to develop a sheet shape measuring device equipped with

  The present invention has been made in view of such circumstances, and without causing damage to the sheet when optically measuring the shape of a sheet that is worried about quality failure with respect to scratches or light and is not flat. In addition, since the distance between the sheet and the optical measuring instrument can be kept constant, highly accurate measurement can be performed, for example, a sheet shape measuring method that is particularly effective when measuring the shape of a lithographic printing plate as a sheet and An object is to provide an apparatus.

  According to a first aspect of the present invention, in order to achieve the above object, in the sheet shape measuring method for optically measuring the shape of the sheet being conveyed on-line, a non-contact pressure is applied to one surface of the front and back surfaces of the sheet. The other surface of the sheet is pressed against a pressing surface of a backing member provided on the opposite side of the moving belt through a moving belt that moves at the same speed in the same direction as the sheet conveying direction, and the sheet is The shape of the sheet is optically measured online while following the pressing surface.

  According to the first aspect of the present invention, the non-contact pressure is applied to one surface of the front and back surfaces of the sheet, and the other surface of the sheet moves through the moving belt at the same speed in the same direction as the sheet conveying direction. The sheet is pressed against the pressing surface of the backing member provided on the opposite side so that the sheet follows the pressing surface. As a result, even if the sheet is not flat due to curl or the like, the sheet shape is corrected following the shape of the pressing surface, and the sheet is supported by non-contact pressure, so the sheet does not hang down. . Further, since the position of the backing member and the position of the measuring instrument that performs optical measurement are fixed, the distance between the pressing surface and the measuring instrument is always constant. Therefore, since the distance between the sheet corrected according to the pressing surface and the measuring instrument is also constant, the distance accuracy between the sheet and the measuring instrument required for optical sheet shape measurement can be sufficiently achieved.

  Also, even if the other side of the front and back surfaces of the sheet is a surface where there is a risk of quality failure due to scratches, the sheet follows the pressing surface while moving together with the moving moving belt. Will not be damaged by rubbing against the pressing surface. Furthermore, since non-contact pressure is applied to one side of the sheet, a measuring instrument that performs optical measurement is arranged on one side of the sheet to irradiate one side of the sheet with a measuring beam. It becomes possible. Therefore, if the other side of the sheet is a surface where quality failure is a concern due to scratches or light, if the other side of the sheet is supported by a moving belt and irradiated with light on one side, the other side of the sheet will be scratched or lighted. The sheet shape can be measured without causing a quality failure.

  In addition, by applying non-contact pressure to one side of the front and back surfaces of the sheet, the moving belt is pressed against the backing member together with the sheet, so that the moving belt may vibrate during measurement of the sheet shape. Absent. Therefore, the measurement accuracy is not lowered by the vibration of the moving belt.

  Due to the above-described effects of the present invention, it is possible to measure the shape of a sheet that is not flat and optically on-line with high accuracy without causing damage to the sheet due to the possibility of quality failure with respect to scratches and light. it can. Therefore, the present invention is particularly effective when measuring the shape of a lithographic printing plate having a photosensitive layer as a sheet.

  A second aspect of the present invention is characterized in that, in the first aspect, the non-contact pressure is a gas pressure generated by blowing a gas onto the one surface of the sheet. A second aspect of the present invention shows a preferred embodiment as a non-contact pressure applied to one surface of the sheet.

  A third aspect is characterized in that, in the first or second aspect, the pressing surface of the backing member is curved in the moving direction of the moving belt. In this way, by curving the pressing surface of the backing member in the moving direction of the moving belt, the curling of the sheet can be corrected more effectively than when the pressing surface is flat, and the sheet hangs down due to its own weight. Prevent more effectively. In this case, when the sheet is rectangular, it is preferable to press the sheet against the pressing surface so that the direction orthogonal to the moving direction of the moving belt coincides with the longitudinal direction of the sheet. Thereby, sagging of the sheet can be more effectively prevented.

  According to a fourth aspect of the present invention, there is provided a sheet shape measuring apparatus for measuring the shape of the sheet on-line with an optical measuring instrument while guiding the sheet being conveyed by a conveying conveyor with a guide mechanism in order to achieve the object. The guide mechanism supports one side of the front and back surfaces of the sheet and moves at the same speed in the same direction as the sheet conveying direction of the conveying conveyor, and on the opposite side of the moving belt to the measuring instrument. A backing member provided oppositely and having a flat pressing surface, and pressure is applied to the other surface of the front and back surfaces of the sheet in a non-contact manner to push the sheet to the pressing surface via the moving belt. And a pressure applying means.

  According to a fourth aspect of the present invention, the apparatus according to the first aspect is configured as an apparatus. When the sheet is conveyed by the guide mechanism having the above-described configuration, a quality failure may be caused with respect to scratches and light, and the sheet is not flat. When the shape is optically measured online, it can be measured with high accuracy without damaging the sheet. Therefore, it is particularly effective when, for example, measuring the shape of a lithographic printing plate having a photosensitive layer as a sheet.

  A fifth aspect of the present invention according to the fourth aspect is characterized in that the pressing surface of the backing member has a curved surface shape curved in the moving direction of the moving belt. Thereby, the curl of the sheet can be corrected similarly to the third aspect, and the sagging of the sheet due to its own weight can be effectively prevented.

  A sixth aspect of the present invention is the method according to the fourth or fifth aspect, wherein the pressure applying unit includes a nozzle that blows a gas toward the pressing surface of the backing member between an upstream position and a downstream position in the sheet conveying direction across the measuring device. And a pair of light sources for measurement, and a light beam for measurement is passed through the gap.

  Claim 6 shows a preferred embodiment of the pressure applying means, which is provided with a pair of nozzles for blowing a gas by opening a gap between an upstream position and a downstream position in the sheet conveying direction across the measuring instrument, and for measuring in the gap. By configuring so as to pass the light beam, the pressure applying means and the measuring device can be arranged on the same side with respect to the moving belt. As a result, when the other side of the sheet is a surface where quality failure is a concern due to scratches or light rays, the other side of the sheet can be obtained by supporting the many sides of the sheet on the moving belt and irradiating one side with light rays. The sheet shape can be measured without causing quality failure due to scratches or light. In this case, it is preferable to set the timing of the gas blown out from the pair of nozzles and the direction of the blowout so that the blown-out gas does not enter between the sheet and the moving belt.

  A seventh aspect of the present invention according to the sixth aspect is characterized in that the nozzle is movable in accordance with the shape of the sheet. This is because gas is blown from the nozzle to any location on the sheet depending on the shape of the sheet, for example, the difference in slit width or cut width due to various sizes and thickness of the sheet, the amount of sag due to its own weight, or the difference in curl state. Thus, it is different whether the sheet can be pressed so as to follow the pressing surface of the backing member. Therefore, the nozzle is not fixedly arranged, but is movably arranged as in claim 7 so that the sheet can be accurately copied to the pressing surface of the backing member regardless of the sheet shape. Can be pressed.

  An eighth aspect according to any one of the fourth to seventh aspects is characterized in that the sheet is a planographic printing plate having a photosensitive layer. This is because the present invention is particularly effective when the sheet is a lithographic printing plate having a photosensitive layer.

  As described above, according to the sheet shape measuring method and apparatus of the present invention, when optically measuring the shape of a sheet which is concerned about quality failure against scratches or light and is not flat, the sheet is measured. Since the distance between the sheet and the optical measuring instrument can be kept constant without being damaged, and the moving belt does not vibrate, high-precision measurement can be performed. Therefore, it is particularly effective in the case of a lithographic printing plate having a photosensitive layer as a sheet, for example.

  Hereinafter, preferred embodiments of a sheet shape measuring method and apparatus according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a processing line 100 for a lithographic printing plate incorporating the sheet shape measuring device 16 of the present invention. In this embodiment, a planographic printing plate having a photosensitive layer as a sheet will be described, but the present invention is not limited to this.

  On the upstream side (upper right side in FIG. 1) of the processing line 100, a sending machine 102 is provided. A long lithographic printing plate 10 (raw material) is wound in a coil shape and attached to the sending machine 102, and the lithographic printing plate 10 is unwound from the sending machine 102 and sent out to the processing line 100. It is. The fed lithographic printing plate 10 is curled and corrected by the leveler 106. The planographic printing plate 10 is controlled so as to travel in the center by the delivery device 102, but may be displaced in the width direction from the center due to a deviation during traveling. For this reason, the vehicle is regulated to travel at a specified position (center position) by a CPC (center position control) device (not shown). As the CPC device, for example, a camera that detects the edge portion position in the width direction of the long lithographic printing plate 10 is provided, and the lithographic printing plate 10 is changed based on the edge portion position detected by the camera. It is preferable that the wound roller is inclined so that the center position in the width direction of the planographic printing plate 10 travels at a fixed position. In this way, the planographic printing plate 10 that is regulated so as to travel in the center position is overlapped with the interleaf 14 at the position of the overlapping device 108 and is charged and bonded.

  On the other hand, the slip sheet 14 is mounted on the transmitter 112 in a coiled state, and is unwound from the transmitter 112 and sent out. Then, after a tension for transport is applied by a dancer roller or the like, the transport position in the width direction is controlled to be the center of the line by an EPC (edge part position control) device (not shown). Thereafter, the slip sheet 14 is trimmed to a predetermined width by the slitter device 114.

  Further, when slitting the interleaf paper 14, the left and right slit positions of the slitter device 114 are positioned so that the line center is accurately distributed. Accordingly, the slip sheet 14 slit by the slitter device 114 travels in the center of the line and is overlapped with the planographic printing plate 10 traveling in the center of the line. Hereinafter, a web 116 in which a long planographic printing plate 10 and a slip sheet 14 are overlapped is referred to as a web 116.

  The web 116 is transferred to the notch 118, and the notch 118 punches out the ear portion of the web 116. In accordance with this punching position, a trimming upper blade 122 and a trimming lower blade 124 of a slitter device 120 described later are moved in the width direction of the planographic printing plate 10.

  The web 116 with the ears punched out by the notch 118 is transferred to the slitter device 120 and trimmed to a predetermined slit width by the trimming upper blade 122 and the trimming lower blade 124 of the slitter device 120. At that time, since the trimming upper blade 122 and the trimming lower blade 124 move in the width direction of the web 116 according to the punching position, the trimming width (slit width) can be changed while the web 116 is continuously cut.

  The web 116 cut to a predetermined slit width is cut by the running cutter 128 with the instructed cut length after the feed length is detected by the length measuring device 126. Thereby, the lithographic printing plate 10A having the set size is manufactured. The product size of the planographic printing plate 10A is not particularly limited. For example, a thickness of 0.1 to 0.5 mm, a lengthwise dimension (slit width) of 200 to 2000 mm, and a lengthwise dimension (cut width) of 400 to 2000 mm are preferable. .

  The lithographic printing plate 10A having the product size is optically measured by the sheet shape measuring device 16 according to the present invention, and the lithographic printing plate shape (slit width, cut length, squareness) is optically measured. Then, the accepted product is transferred to the accumulator 134 by the conveyor 132.

  In the stacking device 134, a predetermined number of lithographic printing plates 10A on which the interleaf sheets 14 are bonded are stacked. As a result, the planographic printing plate 10A and the interleaf paper 14 are alternately laminated to form a laminated bundle 12 of the planographic printing plate 10A. The number of lithographic printing plates 10 constituting one laminated bundle 12 is not particularly limited, but may be, for example, 10 to 100 from the viewpoint of efficiency of transportation and storage. Note that two laminating devices 134 may be provided and alternately laminated. Thereby, the web 116 can be continuously cut even while the laminated bundle 12 is carried out.

  Next, the sheet shape measuring apparatus 16 of the present invention will be described.

  FIG. 2 is a perspective view illustrating the sheet shape measuring device 16 in a state in which the moving belt 22 and the backing member 44 are separated from the transport mechanism 20 in order to easily illustrate the structures of the guide mechanism 18 and the transport mechanism 20. is there. 3 and 4 are side cross-sectional views along the conveying direction of the planographic printing plate 10A of the sheet shape measuring apparatus 16, FIG. 3 shows a shape measurement start state of the planographic printing plate 10A, and FIG. 4 shows a shape measurement end state. The planographic printing plate 10A is conveyed from the left side to the right side in FIGS. FIG. 5 is a front cross-sectional view of the sheet shape measuring device 16, and the planographic printing plate is conveyed from the back surface to the front surface in FIG.

  As shown in these drawings, the sheet shape measuring device 16 includes a pair of optical measuring mechanisms 24 disposed at locations where the left and right edge portions a, a of the planographic printing plate 10A pass. , 24, a transport mechanism 20 that transports the planographic printing plate 10A so as to pass through the pair of optical measurement mechanisms 24, 24, and guides the transport of the planographic printing plate 10A when measuring the shape of the planographic printing plate 10A. The guide mechanism 18 is configured to be

  The optical measuring mechanism 24 is mainly composed of an illuminator 30 that irradiates a lithographic printing plate 10A with a measuring beam, a CCD line sensor 32 (measuring device) that continuously images the lithographic printing plate 10A, and a CCD line sensor 32. An image processing apparatus (not shown) that processes continuously captured images and a personal computer that calculates the shape of a planographic printing plate based on data obtained by the image processing are configured. The illuminators 30 do not have to be a pair, and one illuminator 30 may illuminate the left and right edge portions a and a of the planographic printing plate 10A.

  The resolution and scan speed of the CCD line sensor 32 are selected in accordance with the required measurement accuracy and line speed (transport speed of the planographic printing plate 10A). For example, the dimensional accuracy of the slit width in the lithographic printing plate 10A is ± 0.125 mm, the cut length is ± 0.25 mm, the perpendicularity is ± 0.02 °, the meandering of the lithographic printing plate 10A is within 5 mm, and the line speed is 150 m. / Min, a lens for measuring a width of 20 mm is attached to a CCD line sensor 32 of 1024 bits-100 MHz, and the left and right edge portions a, a of the planographic printing plate 10A may be continuously imaged. In this case, the resolution is about 20 μm in the width direction of the planographic printing plate 10A, and the maximum is about 30 μm in the transport direction.

  Then, while illuminating the lithographic printing plate 10A being conveyed by the illuminator 30, the left and right edge portions a and a of the lithographic printing plate 10A are continuously imaged by the pair of CCD line sensors 32 and 32, and the continuously imaged image is processed. When the binarization processing is performed by the apparatus, the binarized image shown in FIG. 6 is obtained, and the image portion (boundary surface) of the planographic printing plate 10A is extracted from the image portion other than the planographic printing plate 10A. The dark portion in FIG. 6 is an image portion corresponding to the lithographic printing plate 10A, and the light color portion is an image portion of the moving belt 22 other than the lithographic printing plate 10A. The personal computer calculates the resolution for each pixel of the camera at the line speed obtained from the obtained binarized image and the line pulse, draws four approximate straight lines on the four sides of the rectangular planographic printing plate 10A, and creates four lines. The slit width, slit length, and squareness are calculated from the distance between the intersections of the approximate lines and the angle at which the approximate lines intersect. Thereby, the shape (slit width, slit length, squareness) of the planographic printing plate 10A can be measured.

  However, as described above, the photosensitive layer of the lithographic printing plate 10A is liable to be damaged due to scratches or irradiation light, and the lithographic printing plate 10A is not completely flat due to curling or the like. It is difficult to always maintain the distance of 10A, particularly the left and right edge portions a and a which are the imaging portions of the planographic printing plate 10A, constantly.

  Therefore, the sheet shape measuring apparatus 16 of the present invention is provided with a guide mechanism 18 that appropriately guides the lithographic printing plate 10A when measuring the shape of the lithographic printing plate 10A conveyed by the conveyance mechanism 20.

  As shown in FIG. 2, the transport mechanism 20 mainly includes a belt-type center row conveyor 34, a belt-type right row conveyor 36 (right side in the traveling direction of the center row conveyor), and a belt-type left row conveyor 38 (center row conveyor). Belt-type upstream conveyor 40, which is composed of three parallel rows of conveyors 34, 36, 38 in the direction of travel of the right side) and the right row conveyor 36 and the left row conveyor 38 spaced apart from each other by a predetermined distance. It comprises a belt-type downstream conveyor 42. When the planographic printing plate 10A conveyed by the three rows of conveyors 34, 36, 38 is transferred from the upstream conveyor 40 to the downstream conveyor 42, the left and right edge portions a, a of the planographic printing plate 10A are paired with a pair of CCDs. Continuous imaging is performed by the line sensors 32 and 32. In this case, the line speed in the shape measurement of the planographic printing plate 10A is preferably in the range of 40 to 150 m / min.

  The guide mechanism 18 mainly supports the photosensitive layer surface side of the planographic printing plate 10A and moves at the same speed in the same direction as the transport direction of the planographic printing plate 10A by the transport mechanism 20, and the planographic printing of the movable belt 22 A backing member 44 provided on the opposite side of the plate 10A and facing the CCD line sensor 32, having a pressing surface 44A curved in the moving direction of the moving belt 22 and having excellent flatness without unevenness on the surface; Pressure applying means 46 for applying a non-contact gas pressure to the lithographic printing plate 10A by blowing gas onto the surface of the anti-photosensitive layer of the printing plate 10A and pressing the lithographic printing plate 10A against the pressing surface 44A via the moving belt 22; , Composed of. The backing member 44 is formed as a fixed object, and the moving belt 22 moves while being in sliding contact with the pressing surface 44A of the backing member 44. Reference numeral 48 denotes a conveyor pass roller. The gas used is generally air, but an inert gas such as nitrogen gas may be used.

  As shown in FIGS. 2 to 5, the pressure applying means 46 has a gap between the nozzles 52 </ b> A and 52 </ b> B that blow gas toward the pressing surface 44 </ b> A of the backing member 44 between the upstream position and the downstream position in the planographic printing plate 10 </ b> A conveyance direction. A pair is provided with an opening 54. The gap 54 is used to illuminate the planographic printing plate 10 A from the illuminator 30, and the reflected light is received by the CCD line sensor 32 through the gap 54. The pair of nozzles 52A and 52B are further provided at the left and right edge portions a and a of the planographic printing plate 10A, respectively (see FIG. 5), and the pressure applying means 46 is composed of a total of four nozzles.

  And, when the planographic printing plate 10A is transferred from the upstream conveyor 40 to the downstream conveyor 42, as shown in FIG. The front end portion of the planographic printing plate 10 </ b> A is pressed against the backing member 44 via the moving belt 22. Next, when the front end of the planographic printing plate 10A enters the position of the center line 48A of the pass roller 48 of the downstream conveyor 42, gas is also blown out from the nozzle 52B. Thus, it is possible to prevent the gas blown from the nozzle 52B from entering between the front end of the planographic printing plate 10A and the moving belt 22 and causing the planographic printing plate 10A to flutter. Next, when the rear end of the planographic printing plate 10A is separated from the position of the center line 48A of the pass roller 48 of the upstream conveyor 40, the blowing of gas from the nozzle 52A is stopped as shown in FIG. Thereby, it is possible to prevent the gas blown from the nozzle 52A from entering between the rear end of the planographic printing plate 10A and the moving belt 22 and causing the planographic printing plate 10A to flutter. In this case, as shown in FIG. 5, the gas from the nozzles 52A and 52A arranged at the positions of the upstream left and right edges a and a is blown from the inside to the outside with respect to the left and right edges a and a of the planographic printing plate 10A. It is preferable to set the direction of the nozzles 52A and 52A toward the outside in the planographic printing plate width direction. Similarly, the nozzle 52B is arranged so that the gas from the nozzles 52B and 52B arranged at the positions of the left and right edges a and a on the downstream side is blown from the inside to the outside with respect to the left and right edges a and a of the planographic printing plate 10A. , 52B is preferably set toward the outside in the width direction of the planographic printing plate. Thereby, not only can the curl of the lithographic printing plate 10A be effectively corrected, but the gas blown from the nozzles 52A and 52B enters between the both side ends of the lithographic printing plate 10A and the moving belt 22, and the lithographic printing plate It is possible to prevent 10A from fluttering. As a result, the planographic printing plate 10A can effectively follow the pressing surface 44A of the backing member 44, and even if gas is blown from the nozzles 52A and 52B to the planographic printing plate 10A, Since the gas blown from the nozzles 52A and 52B does not enter between the moving belt 22 and the lithographic printing plate 10A flutters with the gas blown during continuous imaging by the CCD line sensor 32 of the lithographic printing plate 10A. There is nothing. The pressure of the gas blown from the nozzles 52A and 52B is preferably in the range of 0.05 to 0.3 MPa, and the distance between the nozzle ports of the nozzles 52A and 52B and the planographic printing plate 10A is preferably in the range of 1 to 10 mm. In particular, during online measurement, the lithographic printing plate 10A is lifted (without contact with the transport mechanisms 34, 36, 38) by the gas pressure blown from the nozzles 52A, 52B, and the pressing surface of the backing member 44 is pressed. It is preferable to generate a gas pressure sufficient to press against 44A. This is because the moving belt 22 is set so as to move at the same speed in the same direction as the conveying direction of the conveying mechanism 20, but if the speeds of the moving belt 22 and the conveying mechanism 20 are not completely synchronized, lithographic printing is performed. This is because there is a possibility that the plate 10A may be rubbed and scratched. Therefore, the lithographic printing plate 10A can be surely solved by floating. In this floated state, the planographic printing plate 10A moves along with the movement of the moving belt 22 while being supported by the gas pressure.

  The pair of nozzles 52A and 52B is configured to be movable along the transport direction of the planographic printing plate 10A as indicated by the arrow 51 in FIGS. 3 and 4, and as indicated by the arrow 53 in FIG. The lithographic printing plate 10A is preferably configured to be movable in the width direction. This is because the nozzles 52A and 52B are different depending on the shape of the lithographic printing plate 10A, for example, the difference in slit width and cut width due to various sizes and thicknesses of the lithographic printing plate 10A, the amount of sag due to its own weight, or the difference in curling state. This is because where the gas is blown onto the lithographic printing plate 10A from which the lithographic printing plate 10A can be pressed so as to follow the pressing surface 44A of the backing member 44. Therefore, the nozzles 52A and 52B are not fixedly arranged, but can be moved in the transport direction and the width direction of the planographic printing plate 10A, so that the planographic printing plate 10A can have any shape. The printing plate 10A can be pressed with high precision so as to follow the pressing surface of the backing member. Although the moving mechanism of the nozzles 52A and 52B is not particularly shown, a known moving mechanism such as a feed screw, a mechanism, or a cylinder mechanism can be used.

  As described above, according to the sheet shape measuring apparatus 16 of the present invention, the guide mechanism 18 configured as described above applies a gas pressure from the nozzles 52A and 52B to the surface of the lithographic printing plate 10A from the nozzles 52A and 52B. The photosensitive layer surface is pressed against the flat pressing surface 44A of the backing member 44 via the moving belt 22 that moves at the same speed in the same direction as the transport direction of the planographic printing plate 10A, and the planographic printing plate 10A is pressed against the pressing surface 44A. I tried to follow. As a result, even if the planographic printing plate 10A is not flat due to curling or the like, the shape of the planographic printing plate 10A is corrected following the shape of the pressing surface 44A, and the planographic printing plate 10A is supported by the gas pressure. Therefore, the front end portion and the rear end portion of the planographic printing plate 10 do not hang down. In particular, in the present embodiment, the pressing surface 44A of the backing member 44 is curved in the moving direction of the moving belt 22, so that the planographic printing plate 10A is compared with the case where the pressing surface 44A is flat. Curling wrinkles and minute irregularities can be more effectively corrected, and dripping of the planographic printing plate 10A due to its own weight can be more effectively prevented. In this case, as shown in FIG. 2, it is preferable to press the planographic printing plate 10A against the pressing surface 44A so that the direction orthogonal to the moving direction of the moving belt 22 coincides with the longitudinal direction of the planographic printing plate 10A. . Thereby, drooping of the planographic printing plate 10A can be more effectively prevented.

  Further, since the position of the backing member 44 and the position of the CCD line sensor 32 are fixed, the distance between the pressing surface 44A and the CCD line sensor 32 is always constant. Accordingly, the distance between the lithographic printing plate 10A corrected according to the pressing surface 44A and the CCD line sensor 32 is also constant, and therefore the distance accuracy between the lithographic printing plate 10A and the CCD line sensor 32 required for optical measurement. Can be fully achieved.

  Also, the photosensitive layer surface of the lithographic printing plate 10A becomes a quality failure when scratched, but the lithographic printing plate 10A follows the pressing surface 44A while moving together with the moving belt 22, so that the lithographic printing plate 10A No rubbing is caused by pressing the photosensitive layer surface against the pressing surface 44A. Therefore, the photosensitive layer surface is not damaged. Furthermore, the photosensitive layer surface of the lithographic printing plate 10A may cause quality failure due to the light from the illuminator 30, but since a gas pressure is applied to the anti-photosensitive layer surface of the lithographic printing plate 10A, the lithographic printing plate The illuminator 30 and the CCD line sensor 32 can be arranged on the side opposite to the photosensitive layer surface of 10A, and the photosensitive layer surface does not cause quality failure due to the illumination of the illuminator 30. In the planographic printing plate 10A, the slip sheet 14 is superimposed on the photosensitive layer surface. When measured from the photosensitive layer surface side, the slippage of the slip sheet 14 causes erroneous measurement. In the present invention, however, measurement is performed from the anti-photosensitive layer surface. Even if the slip sheet 14 is misaligned, no erroneous measurement occurs. Further, if the planographic printing plate 10A flutters with the gas from the nozzles 52A and 52B or the moving belt 22 vibrates, it may cause erroneous measurement. As described above, the timing of the nozzles 52A and 52B blowing out and the nozzles 52A and 52B. Since the orientation of is appropriately set, the lithographic printing plate 10A does not flutter with the gas blown, and the moving belt 22 is pressed against the backing member 44 together with the lithographic printing plate 10A. The moving belt 22 does not vibrate during the shape measurement.

  In FIG. 7, the guide mechanism 18 is turned upside down. A pair of nozzles 52A and 52B are provided on the upper side of the planographic printing plate 10A, and the moving belt 22 and the backing member 44 are disposed on the lower side of the planographic printing plate 10A. It is a thing. In this case, the illuminator 30 and the CCD line sensor 32 are arranged on the upper side of the planographic printing plate 10A. When such a configuration is applied as the guide mechanism 18 for measuring the shape of the lithographic printing plate 10A, it is preferably applied to a lithographic printing plate having a heat-sensitive layer instead of a photosensitive layer. Of course, the present invention can also be applied to a sheet having no fear of quality failure due to light other than the planographic printing plate 10A. In this way, when the guide mechanism 18 is turned upside down, if the transported lithographic printing plate 10A is a thin plate of about 0.1 mm, it follows the pressing surface 44A of the backing member 44 by its own weight, but is thicker by 0.4 mm or more. Since the lithographic printing plate 10A is rigid, it is necessary to force the lithographic printing plate 10A to follow the pressing surface 44A of the backing member 44 by gas pressure from the nozzles 52A and 52B.

  In the embodiment of the present invention, the lithographic printing plate 10A has been described as an example of the sheet. However, the present invention is not limited to this, and can be applied to a thin steel plate, a resin sheet, and the like. Further, although the example in which the pressing surface 44A of the backing member 44 is curved in the moving direction of the moving belt 22 has been described, the pressing surface 44A may be completely flat. Further, in the present embodiment, the transport mechanism 20 is a part of the processing line 100 and is a separate device from the sheet shape measuring device 16, but the transport mechanism 20 may be a part of the sheet shape measuring device 16. . In the present embodiment, a pair of CCD line sensors 32 are provided at the left and right edges a and a of the planographic printing plate 10A so that continuous imaging is performed from the front end portion to the rear end portion of the transported planographic printing plate 10A. However, four CCD line sensors are provided from the front end portion to the rear end portion of the planographic printing plate 10A, and the left and right edges a and a of the front end portion of the planographic printing plate 10A and the left and right edges a and a of the rear end portion are imaged at a time. You may do it.

  Next, the preferable aspect regarding lithographic printing plate 10A in this invention is demonstrated.

  The planographic printing plate 10A has a coating film (a photosensitive layer in the case of a photosensitive printing plate, a heat sensitive layer in the case of a heat sensitive printing plate, and further necessary on a thin aluminum support formed in a rectangular plate shape. According to the above, an overcoat layer, a mat layer, etc.) are applied. The coating film is subjected to plate making processing such as exposure, development processing, and gumming, set in a printing machine, and ink is applied to print characters, images, and the like on the paper.

  The lithographic printing plate 10 of the present embodiment is a stage before processing (exposure, development, etc.) necessary for printing, and is sometimes referred to as a lithographic printing plate precursor or a lithographic printing plate material. Sometimes. If it is such a configuration, the specific configuration of the planographic printing plate 10A is not particularly limited. For example, by using the planographic printing plate 10A for the laser printing plate of the heat mode method and the photon method, from the digital data A lithographic printing plate 10A capable of direct plate making can be obtained.

Further, the lithographic printing plate 10A can be a lithographic printing plate corresponding to various plate making methods by selecting various components in the photosensitive layer or the thermosensitive layer. Examples of specific embodiments of the lithographic printing plate 10A of the present invention include the following embodiments (1) to (11).
(1) A mode in which the photosensitive layer contains an infrared absorber, a compound that generates an acid by heat, and a compound that crosslinks by an acid.
(2) An embodiment in which the photosensitive layer contains an infrared absorber and a compound that becomes alkali-soluble by heat.
(3) An embodiment in which the photosensitive layer includes two layers, a layer containing a compound that generates radicals upon irradiation with laser light, an alkali-soluble binder, and a polyfunctional monomer or prepolymer, and an oxygen blocking layer.
(4) A mode in which the photosensitive layer is composed of two layers of a physical development nucleus layer and a silver halide emulsion layer.
(5) A mode in which the photosensitive layer includes three layers of a polymerization layer containing a polyfunctional monomer and a polyfunctional binder, a layer containing silver halide and a reducing agent, and an oxygen blocking layer.
(6) A mode in which the photosensitive layer includes two layers of a layer containing a novolak resin and naphthoquinone diazide and a layer containing a silver halide.
(7) A mode in which the photosensitive layer contains an organic photoconductor.
(8) A mode in which the photosensitive layer includes 2 to 3 layers including a laser light absorbing layer to be removed by laser light irradiation, and a lipophilic layer and / or a hydrophilic layer.
(9) A compound in which the photosensitive layer absorbs energy to generate an acid, a polymer compound having a functional group that generates sulfonic acid or carboxylic acid by an acid in the side chain, and an acid generator by absorbing visible light The aspect containing the compound which gives energy to.
(10) A mode in which the photosensitive layer contains a quinonediazide compound and a novolac resin.
(11) A mode in which the photosensitive layer contains a compound that decomposes by light or ultraviolet rays to form a crosslinked structure with itself or other molecules in the layer and an alkali-soluble binder.

  In particular, in the planographic printing plate 10A having a photosensitive layer (or heat-sensitive layer) whose solubility in a developing solution is changed by laser light irradiation, the image forming surface (photosensitive layer or heat-sensitive layer) is easily damaged, and thus the present invention is applied. Then, as will be described later, so-called film peeling can be reliably prevented, which is preferable.

  The wavelength of the laser light here is not particularly limited. For example, (A) a laser having a wavelength range of 350 to 450 nm (specifically, a laser diode having a wavelength of 405 ± 5 nm), (B) a wavelength range of 480 to 540 nm. (Specific examples are an argon laser with a wavelength of 488 nm, a (FD) YAG laser with a wavelength of 532 nm, a solid laser with a wavelength of 532 nm, a (green) He—Ne laser with a wavelength of 532 nm), and (C) with a wavelength range of 630 to 680 nm. Lasers (specific examples are He—Ne lasers with wavelengths of 630 to 670 nm, red semiconductor lasers with wavelengths of 630 to 670 nm), (D) lasers with wavelength ranges of 800 to 830 nm (specific examples are infrared rays with a wavelength of 830 nm (semiconductors)) Laser), (E) laser with a wavelength of 1064 to 1080 nm (specifically The, YAG laser having a wavelength of 1064 nm), and the like. Among these, for example, both of the laser beams in the wavelength regions (B) and (C) can be applied to both the lithographic printing plate having the photosensitive layer or the heat-sensitive layer of the above-described aspect (3) or (4). It is. Further, both of the laser beams in the wavelength ranges of (D) and (E) can be applied to both the lithographic printing plate 10A having the photosensitive layer or the heat-sensitive layer of the above-described aspect (1) or (2). Of course, the relationship between the wavelength range of the laser beam and the photosensitive layer or the heat-sensitive layer is not limited thereto.

Configuration diagram of processing line of planographic printing plate incorporating sheet shape measuring apparatus of the present invention The perspective view explaining the conveyance mechanism of a planographic printing plate and the guide mechanism of a sheet shape measuring apparatus FIG. 5 is a side cross-sectional view mainly illustrating a guide mechanism of a sheet shape measuring apparatus and showing a shape measurement start of a lithographic printing plate FIG. 4 is a side cross-sectional view mainly illustrating a guide mechanism of a sheet shape measuring apparatus and showing the end of shape measurement of a lithographic printing plate Front sectional view mainly explaining the guide mechanism of the sheet shape measuring apparatus Explanatory drawing of the binarized image of the left and right edge portions of the planographic printing plate imaged by the CCD line sensor Explanatory drawing of the modification which arranged the guide mechanism upside down

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Long lithographic printing plate, 10A ... Sheet-like lithographic printing plate, 12 ... Laminated bundle, 14 ... Interleaving paper, 16 ... Sheet shape measuring device, 18 ... Guide mechanism, 20 ... Conveyance mechanism, 22 ... Moving belt, 24 ... Measurement mechanism, 30 ... Illuminator, 32 ... CCD line sensor, 34 ... Center row conveyor, 36 ... Right row conveyor, 38 ... Left row conveyor, 40 ... Upstream conveyor, 42 ... Downstream conveyor, 44 ... Backing Member 44A ... Pressing surface 46 ... Pressure applying means 48 ... Pass roller, Nozzle 52A, 52B, 54 ... Gap, 100 ... Processing line 102 ... Sending machine 106 ... Leveler 108 ... Overlapping device 112 ... 114 ... slitter device, 116 ... web, 118 ... notch, 120 ... slitter device, 126 ... length measuring device, 128 ... running cutter, 132 ... conveyor, 34 ... integrated device, a ... lateral edge portions of the planographic printing plate

Claims (8)

In the sheet shape measuring method for optically measuring the shape of the sheet being conveyed on-line,
A non-contact pressure is applied to one surface of the front and back surfaces of the sheet, and the other surface of the sheet is provided on the opposite side of the moving belt via a moving belt that moves at the same speed in the same direction as the sheet conveying direction. A sheet shape measuring method comprising: pressing a sheet against a pressing surface of a backing member, and optically measuring the shape of the sheet with the sheet following the pressing surface.   2. The sheet shape measuring method according to claim 1, wherein the non-contact pressure is a gas pressure generated by blowing a gas onto the sheet.   3. The sheet shape measuring method according to claim 1, wherein the pressing surface of the backing member is curved in the moving direction of the moving belt. In the sheet shape measuring apparatus that measures the shape of the sheet on-line with an optical measuring instrument while guiding the sheet being conveyed on the conveying conveyor with a guide mechanism,
The guide mechanism is
A moving belt that supports one surface of the front and back surfaces of the sheet and moves at the same speed in the same direction as the sheet conveying direction of the conveyor,
A backing member provided on the opposite side of the sheet of the moving belt and facing the measuring instrument and having a pressing surface;
And a pressure applying unit that applies pressure to the other surface of the front and back surfaces of the sheet in a non-contact manner and presses the sheet against the pressing surface via the moving belt. .   5. The sheet shape measuring apparatus according to claim 4, wherein the pressing surface of the backing member has a curved surface shape curved in the moving direction of the moving belt.   The pressure applying means is provided with a pair of nozzles for blowing gas toward the pressing surface of the backing member with a gap between an upstream position and a downstream position in the sheet conveying direction across the measuring device. 6. The sheet shape measuring apparatus according to claim 4, wherein a measuring beam is passed through the sheet.   The sheet shape measuring apparatus according to claim 6, wherein the nozzle is movable in accordance with the shape of the sheet.   8. The sheet shape measuring apparatus according to claim 4, wherein the sheet is a lithographic printing plate having a photosensitive layer.

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