JP5947027B2 - Line sensor, quality control device and sheet-fed printing machine - Google Patents

Description

  The present invention relates to a line sensor, a quality control device, and a sheet-fed printing press that can detect the printing state of a printing sheet.

  Conventionally, a line sensor arranged in the width direction of a strip-shaped printing paper is known. The line sensor includes a light source unit having a plurality of LEDs and a light receiving unit having a plurality of light receiving sensors. The light receiving unit is arranged such that a plurality of light receiving sensors are arranged in one row in the width direction with respect to the printing surface of the printing paper. The light source unit is arranged such that a plurality of LEDs are arranged in two rows with respect to the printing surface of the printing paper with one row of light receiving sensors interposed therebetween.

JP 2008-62392 A

  By the way, according to said structure, the irradiated light irradiated from the light source part inclines with respect to the printing surface of printing paper. Irradiation light applied to the printing surface is reflected by the printing surface and enters the light receiving unit. At this time, the light receiving unit receives reflected light reflected perpendicularly to the printing surface. For this reason, the distance from the light source unit to the irradiation surface is longer than the distance from the irradiation surface to the light receiving unit. If the distance from the light source unit to the irradiation surface becomes long, the irradiation light irradiated from the LED is likely to diffuse. For this reason, it is necessary to increase the light amount of the LEDs or increase the number of LEDs in two rows so that the light amount of the irradiation light on the printing surface is a predetermined light amount.

  Here, there is a demand for providing a line sensor in a sheet-fed printing press that prints a sheet. In this case, it is preferable to provide a line sensor in the vicinity of the pair of printing cylinders because the sheets sequentially fed from the pair of printing cylinders flutter on the paper bottom side when they are separated from the pair of printing cylinders. However, in the conventional configuration, since the plurality of LEDs are arranged in two rows with one row of light receiving sensors interposed therebetween, the apparatus configuration becomes large, so the line sensor is located near a pair of printing cylinders. It is difficult to set up. In addition, when a plurality of LEDs are arranged in a row and the light receiving sensor is arranged in a row, the distance from the light source unit to the irradiation surface is longer than the distance from the irradiation surface to the light receiving unit. As a result, the amount of irradiated light is reduced, and the detection accuracy of the printed state of the sheet by the line sensor may be reduced.

  Therefore, an object of the present invention is to provide a line sensor, a quality control device, and a sheet-fed printing press that can suitably detect the print state of a print sheet while having a compact configuration.

  The line sensor of the present invention detects a printing state of a printing sheet that is sequentially fed from between the impression cylinder and the printing cylinder facing the impression cylinder while being gripped by a claw portion located on the peripheral surface of the impression cylinder. A line sensor of a sheet-fed printing press provided across the width direction of a sheet, and a plurality of LEDs including at least R, G, and B light emission colors are arranged side by side in the width direction at predetermined intervals. The LED light source unit is provided across the width direction so as to face the plurality of LEDs, and the irradiation light is diffused in the width direction while allowing the irradiation light irradiated from the LED light source unit to diffuse in the width direction. A condensing lens that collects light in the conveyance direction of the orthogonal print sheet and a plurality of light receiving elements that are larger than the plurality of LEDs are arranged in the width direction, and the print sheet that is irradiated with the irradiation light condensed by the condensing lens Reflected from the irradiated surface The LED light source unit is provided on the printing cylinder side as compared with the light receiving unit, and irradiates the irradiation light in one direction so that the irradiation angle with respect to the irradiation surface is vertical, The light receiving unit is provided on the opposite side of the printing cylinder across the LED light source unit, and receives the irradiation light irradiated in one direction from the LED light source unit as reflected light through the irradiation surface, and the LED light source unit and the irradiation surface Is shorter than the distance between the irradiation surface and the light receiving portion.

  According to this configuration, the LED light source unit can make the irradiation angle with respect to the irradiation surface vertical, and the distance between the LED light source unit and the irradiation surface is shorter than the distance between the irradiation surface and the light receiving unit. can do. Thereby, since the distance from the LED light source unit to the irradiation surface can be shortened, the amount of light from the LED light source unit on the irradiation surface is increased in order to suppress the diffusion of the irradiation light from the LED light source unit by the distance can be shortened. Can do. Moreover, since the condensing lens can condense irradiation light to an orthogonal direction, the light quantity from the LED light source part in an irradiation surface can further be enlarged. On the other hand, since the condensing lens allows diffusion of the irradiation light in the width direction, a part of each irradiation light irradiated from each LED arranged at a predetermined interval in the width direction is in the width direction. Since they overlap each other, irradiation light can be complemented across the width direction. For this reason, the number of used LEDs can be suppressed. At this time, the LED light source unit irradiates irradiation light in one direction, and the light receiving unit receives irradiation light irradiated in one direction from the LED light source unit as reflected light. The optical path to the light receiving unit can be unidirectional, and the apparatus configuration can be made compact. Further, when the apparatus configuration is compact, it can be disposed close to the impression cylinder and the printing cylinder. That is, since the distance between the impression cylinder and the printing cylinder and the irradiation surface can be shortened, the LED light source unit emits irradiation light to the printing sheet sandwiched between the impression cylinder and the printing cylinder. Irradiation is possible up to the end of the printing cylinder side (paper bottom side). As a result, even if the printing sheet is separated from between the impression cylinder and the printing cylinder and the end of the printing sheet is lifted, the distance between the impression cylinder and the printing cylinder and the irradiation surface is short. A decrease in printing state detection accuracy can be suppressed. Furthermore, since the irradiation angle of the LED light source unit is perpendicular to the irradiation surface, even if the irradiation light is scattered, the scattered irradiation light is difficult to enter the nail portion. For this reason, since it is difficult for the scattered light scattered by the irradiated light to be incident on the light receiving portion, it is possible to suppress the scattered light from entering the light receiving portion, so that it is possible to suppress a decrease in detection accuracy due to the influence of the scattered light, and printing The printing state of the sheet can be suitably detected.

  In this case, it is preferable that the LED light source unit has a larger amount of light at both ends in the width direction of the print sheet than in the center of the print sheet in the width direction.

  According to this configuration, when the width direction of the LED light source unit is substantially the same as the width direction of the print sheet, both ends in the width direction of the print sheet can be obtained even if there is no LED light source unit outside the width direction of the print sheet. By increasing the amount of light at the portion, it is possible to compensate for a decrease in the amount of light at both ends in the width direction of the print sheet. For this reason, the fall of the detection accuracy by the light quantity fall can be suppressed.

  In this case, the apparatus further includes a case that covers the LED light source unit, the condensing lens, and the light receiving unit. The case has a facing surface that faces the irradiation surface, and the facing surface is printed from between the impression cylinder and the printing cylinder. On the downstream side in the sheet conveying direction, the inclined surface is inclined so that the space between the opposing surface and the irradiation surface is widened, and the light receiving unit is provided inside the inclined surface inside the case, and the LED light source unit Is preferably provided between the printing cylinder and the light receiving portion inside the case.

  According to this configuration, when air is blown between the impression cylinder and the printing cylinder in order to suppress flapping of the printing sheet, since the printing sheet and the inclined surface are widened, the blown air is blown. However, air can be suitably introduced between the impression cylinder and the printing cylinder without being hindered by the case.

  In this case, it is preferable to further include a rotation shaft that rotatably supports the case between an irradiation position where the irradiation surface is irradiated with irradiation light and a maintenance position for performing maintenance.

  According to this configuration, since the case can be rotated between the irradiation position and the maintenance position around the rotation axis, the maintenance work can be suitably performed.

  In this case, it is preferable to further include a light receiving side condensing lens that is provided across the width direction and collects the reflected light and enters the light receiving unit.

  According to this configuration, since the amount of reflected light incident on the light receiving unit can be increased, it is possible to suppress a decrease in detection accuracy due to a decrease in the amount of light.

  A quality management apparatus according to the present invention includes the above-described line sensor, and a control device that controls a printing process for the print sheet based on a print state of the print sheet detected by the line sensor.

  According to this configuration, it is possible to use a compact line sensor that suitably detects the print state of the print sheet. For this reason, the printing process can be controlled by the control device using a line sensor suitable for a sheet-fed printing machine so that the printing state of the printing sheet is good. Thereby, the printing quality of a printing sheet can be maintained suitably.

  The sheet-fed printing press according to the present invention includes a paper feeding device capable of supplying a printing sheet, a printing device that performs a printing process on the printing sheet supplied from the paper feeding device, and a printing state of the printed sheet after printing. A line sensor; a paper discharge device that discharges the print sheet; and a control device that controls print processing on the print sheet based on a print state of the print sheet detected by the line sensor. To do.

  According to this configuration, it is possible to use a compact line sensor that suitably detects the printing state of the printing sheet, and therefore it is possible to dispose the line sensor close to the impression cylinder and the printing cylinder. . In other words, since the distance between the impression cylinder and the printing cylinder and the irradiation surface can be shortened, the line sensor prints the irradiation light on the printing sheet sandwiched between the impression cylinder and the printing cylinder. Irradiation is possible up to the end on the trunk side. As a result, even if the printing sheet is separated from between the impression cylinder and the printing cylinder and the end of the printing sheet is lifted, the distance between the impression cylinder and the printing cylinder and the irradiation surface is short. Further, it is possible to suppress a decrease in detection accuracy due to the floating of the print sheet. Therefore, since the control device can control the printing process based on the printing state of the printing sheet that is preferably detected by the line sensor, it is possible to appropriately ensure the printing quality of the printing sheet.

  According to the line sensor, the quality control device, and the sheet-fed printing press of the present invention, it is possible to suitably detect the print state of the print sheet while having a compact configuration, thereby appropriately ensuring the print quality of the print sheet. can do.

FIG. 1 is a schematic configuration diagram illustrating a sheet-fed printing press according to the present embodiment. FIG. 2 is a schematic configuration diagram showing a configuration around the line sensor. FIG. 3 is a partial cross-sectional view showing a part of the line sensor. FIG. 4 is an explanatory diagram showing a plurality of LEDs and a plurality of light receiving elements. FIG. 5 is an explanatory diagram showing irradiation light irradiated from a plurality of LEDs through a condenser lens. FIG. 6 is a graph showing the amount of irradiation light in the sheet transport direction. FIG. 7 is a graph showing the amount of irradiation light in the width direction of the sheet. FIG. 8 is a block diagram functionally showing the control system of the sheet-fed printing press according to the present embodiment. FIG. 9 is a schematic configuration diagram showing a line sensor in the opposite direction to the optical path of the present embodiment.

  Hereinafter, a line sensor and a sheet-fed printing press according to the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following examples. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic configuration diagram illustrating a sheet-fed printing press according to the present embodiment. FIG. 2 is a schematic configuration diagram showing a configuration around the line sensor. As shown in FIG. 1, the sheet-fed printing press 1 of a present Example is an offset sheet-fed printing machine which can implement single-sided printing with respect to the sheet S as a printing sheet. In this embodiment, the description is applied to the sheet-fed printing press 1 that performs single-sided printing. However, the present invention may be applied to a sheet-fed printing press that performs double-sided printing.

  The sheet-fed printing machine 1 includes a printing machine main body 5 including a paper feeding unit 11, a printing unit 12, and a paper discharge unit 13, and a control device 6. The sheet S may be any printing sheet, and includes, for example, printing paper, a printing film, and the like. In the printer main body 5, the paper feeding unit 11, the printing unit 12, and the paper discharge unit 13 are arranged in series in the transport direction of the sheet S.

  The paper supply unit 11 includes a paper supply table 21 and a paper supply mechanism (separator device) 22. The paper feed tray 21 stacks and places the sheets S, and the paper feed mechanism 22 puts a large number of sheets S stacked on the paper feed tray 21 one by one in order from the top. It is picked up and sent out. In this case, the paper feed tray 21 can be moved up and down in response to the supply of the sheet S so that the paper feed mechanism 22 can maintain a substantially constant height positional relationship with the sheet S. .

  A transport mechanism 23 is disposed between the paper feeding unit 11 and the printing unit 12. The transport mechanism 23 transports the sheet S sent out from the paper supply unit 11, positions the sheet S at a predetermined position by a front contact (not shown), and supplies the positioned sheet S to the printing unit 12. Is.

  The printing unit 12 has four printing units 12a, 12b, 12c, corresponding to four colors of black, black, cyan, yellow, and yellow so that color printing can be realized. 12d. Each of the printing units 12a, 12b, 12c, and 12d has substantially the same configuration, and includes an inking device 36, a plate cylinder 32, a blanket cylinder 33, an impression cylinder 34, and an intermediate cylinder 35. A plurality of ink rollers serving as ink supply paths are disposed between the ink device 36 and the plate cylinder 32.

  As shown in FIG. 2, the ink device 36 supplies ink toward the plate cylinder 32, and an ink fountain 37 that can store ink, an ink source roller 38, an ink key 39, and an ink key opening adjustment. Part 40. The ink base roller 38 draws the ink stored in the ink fountain 37 by rotating. The ink key 39 can be adjusted in the amount of ink drawn out by the ink source roller 38 by adjusting the opening degree of the ink key opening adjustment unit 40. At this time, the ink key opening degree adjusting unit 40 is connected to the control device 6, and the opening degree of the ink key 39 can be controlled by the control device 6.

  The plate cylinder 32, the blanket cylinder 33, and the impression cylinder 34 are arranged so as to contact each other in this order from the upper side to the lower side in the vertical direction. An intermediate cylinder 35 is disposed between the impression cylinders 34 of the printing units 12a, 12b, 12c, and 12d. The inking device 36 supplies ink to the blanket cylinder 33 via the plate cylinder 32 and passes the sheet S between the blanket cylinder 33 and the impression cylinder 34. Ink (picture) is transferred to

  The paper discharge unit 13 conveys the sheets S printed by the printing unit 12 and stacks them in an aligned state. The paper discharge unit 13 includes a chain gripper mechanism 41 that transports the sheets S, a paper discharge table 42 on which the printed sheets S are stacked, and a direction in which the sheets S travel on the paper discharge table 25. And a paper pad 43 for regulating the downstream side position. The chain gripper mechanism 41 receives the sheet S from the printing unit 12d disposed on the most downstream side with respect to the traveling direction of the sheet S, and conveys the sheet S to a predetermined position above the sheet discharge table 42. The chain gripper mechanism 41 has a pair of sprockets 45, 46, an endless chain 47, and a plurality of claws 49 provided on the chain 48 at equal intervals. The sheet discharge table 42 is continuous or stepwise so that the drop distance of the sheet S becomes substantially constant when the height of the top surface of the uppermost stage rises as the sheets S are stacked. Can be moved up and down.

  A line sensor 50 used for inspecting the quality of the printed sheet S is disposed in the printing unit 12d disposed on the most downstream side. The line sensor 50 is disposed over the entire width of the sheet S, and can detect the printing state of the printing surface of the sheet S when the sheet S is conveyed. The quality inspection using the line sensor 50 will be described later.

  Therefore, in the printing machine main body 5 of the sheet printing machine 1 according to the first embodiment described above, when performing color printing, the sheets S stacked on the sheet feeding table 21 of the sheet feeding unit 11 are fed by the sheet feeding mechanism 22. One sheet is taken out from the top and sent to the transport mechanism 23. The transport mechanism 23 positions the sheets S at a predetermined position and then sequentially supplies them to the printing unit 12. In the printing unit 12, printing patterns of four colors are printed on the printing surface of the sheet S by the printing units 12a, 12b, 12c, and 12d. The sheet S on which the printing patterns of four colors are printed is conveyed from the printing unit 12 while being held by the claw 49 of the chain gripper mechanism 41 of the paper discharge unit 13 and stacked on the paper discharge table 42.

  Next, the configuration around the line sensor 50 will be described with reference to FIG. The line sensor 50 is provided on the upper side of the impression cylinder 34 of the printing unit 12d that is the final color, and is provided to face the impression cylinder 34. That is, in the printing unit 12d, the plate cylinder 32, the blanket cylinder 33, and the impression cylinder 34 are arranged in series contact with each other in the vertical direction, and the line sensor 50 rotates more than the blanket cylinder 33 and the impression cylinder 34. It is located on the downstream side in the direction (the conveyance direction of the sheet S) and is provided to face the impression cylinder 34. In this case, since the impression cylinder 34 of the printing unit 12d is configured as the final impression cylinder in the printing unit 12, the line sensor 50 can detect the printing state of the sheet S after printing. ing. The impression cylinder 34 is a double cylinder with respect to the plate cylinder 32 and the blanket cylinder 33, and the plate cylinder 32 and the blanket cylinder 33 rotate twice in synchronism while the impression cylinder 34 rotates once.

  The impression cylinder 34 is provided with one holding claw 34a, 34b capable of holding the front end portion of the sheet S on the outer peripheral portion at equal intervals in the circumferential direction. In addition, a gap 52 that is recessed toward the center is formed on the outer peripheral surface of the blanket cylinder 33. At this time, the blanket cylinder 33 is provided with the gap 52 and the holding claws 34a, 34b facing each other so as to avoid contact with the holding claws 34a, 34b of the impression cylinder 34 on the outer peripheral surface. For this reason, when the impression cylinder 34 and the blanket cylinder 33 rotate in synchronism, the rotation phases of the holding claws 34a and 34b and the gap 52 coincide with each other, so that contact between them is avoided.

  The line sensor 50 is connected to the control device 6, and the control device 6 controls the printing process by the printing machine body 5 based on the printing state of the printing surface of the sheet S detected by the line sensor 50. Thus, the print quality of the sheet S is maintained. That is, the line sensor 50 and the control device 6 function as a quality management device.

  A pair of air nozzles 55 are provided on both sides of the sheet S in the conveyance direction with the line sensor 50 interposed therebetween. The pair of air nozzles 55 is connected to an air supply device (not shown), and each air nozzle 55 is provided across the width direction of the sheet S. The pair of air nozzles 55 blows air supplied from the air supply device toward the space between the blanket cylinder 33 and the impression cylinder 34.

  Next, the line sensor 50 will be specifically described with reference to FIG. FIG. 3 is a partial cross-sectional view showing a part of the line sensor. The line sensor 50 irradiates the sheet S sent from between the impression cylinder 34 and the blanket cylinder (printing cylinder) 33 with irradiation light and receives the reflected light reflected from the sheet S to obtain a sheet. The printing state of the leaf paper S is detected. The line sensor 50 is connected to the control device 6 and outputs the printing state of the sheet S to the control device 6. The line sensor 50 includes an LED light source unit 61, a condensing lens 62, a condensing lens (light-receiving side condensing lens) 63, a light receiving unit 64, and a cover case 65 covering these.

  The cover case 65 is formed in a rectangular shape that is long in the width direction. The cover case 65 has an opposite surface on the upstream side in the conveyance direction among the opposed surfaces facing the irradiation surface of the sheet S that circulates around the impression cylinder 34, while the opposite surface on the downstream side in the conveyance direction. The inclined surface 65b is inclined so as to spread from the irradiation surface. The inclined surface 65b is inclined 45 ° with respect to the horizontal surface 65a. For this reason, the air blown from the air nozzle 55 on the inclined surface side (the downstream side in the transport direction) easily flows between the inclined surface 65 b and the impression cylinder 34. In the present embodiment, the inclined surface 65b is set to 45 °, but is not limited to this angle. At this time, the blowing angle of the air blown from the air nozzle 55 is an angle matched to the inclined surface 65b, but it may be a blowing angle close to the horizontal direction so as not to blow against the cover case 65. . Further, the horizontal surface 65a of the cover case 65 is provided with a transmission window 68 through which irradiation light and reflected light pass, and the transmission window 68 is made of a transparent acrylic plate. A light receiving portion 64 is provided inside the inclined surface 65 b of the cover case 65.

  The cover case 65 is attached to a rotation shaft 70 that rotatably supports the line sensor 50. The rotation shaft 70 rotatably supports the cover case 65 between an irradiation position where the irradiation light is irradiated and a maintenance position for performing maintenance. The irradiation position is a position where the transmission window 68 of the cover case 65 is horizontal. The maintenance position is a position where the transmission window 68 of the cover case 65 is rotated about the rotation shaft 70 in a direction away from the blanket cylinder 33, and is a position where maintenance work is possible. For example, the transmission window 68 is wiped off from the cover case 65 moved to the maintenance position as maintenance.

  FIG. 4 is an explanatory diagram showing a plurality of LEDs and a plurality of light receiving elements. FIG. 5 is an explanatory diagram showing irradiation light irradiated from a plurality of LEDs through a condenser lens. As shown in FIG. 4, the LED light source unit 61 has a plurality of LEDs 73 arranged side by side in the width direction. The plurality of LEDs 73 includes an LED 73a that emits red light (R color), an LED 73b that emits green light (G color), an LED 73c that emits blue light (B color), and an LED 73d that emits infrared light (Ir). ing. In this embodiment, R, G, B, and Ir LEDs 73a, 73b, 73c, and 73d are used. However, at least R, G, and B LEDs 73a, 73b, and 73c may be used.

  In the plurality of LEDs 73, the LEDs 73a, 73b, 73c, and 73d in a predetermined order are grouped into one group, and the groups are arranged in the width direction. That is, the LEDs 73a, 73b, 73c, 73d are arranged in the width direction so that the predetermined order is repeated in the plurality of LEDs 73. The plurality of LEDs 73 have a predetermined interval between adjacent LEDs 73. At this time, as shown in FIG. 5, the predetermined interval is such that the irradiation light emitted from the same type of LEDs 73a, 73b, 73c, 73d extends from the end in the width direction to the center, that is, in a part in the width direction. The intervals are overlapping. Thereby, for example, a part in the width direction of the irradiation light emitted from the R color LED 73a overlaps with a part in the width direction of the irradiation light emitted from the next R color LED 73a in the width direction. The light emitted from the R-color LED 73a complements each other in the width direction.

  The LED light source unit 61 configured as described above is disposed inside the cover case 65 and provided on the blanket cylinder 33 side as compared with the light receiving unit 64. Further, the LED light source unit 61 irradiates the irradiation surface of the sheet S around the impression cylinder 34 in one direction through the transmission window 68 toward the light receiving unit 64. At this time, the LED light source unit 61 irradiates the irradiation light so that the irradiation angle with respect to the irradiation surface of the sheet S is vertical, that is, 90 °.

  In addition, the LED light source unit 61 has a width direction of the sheet S that is larger than the light amount at the center of the width direction of the sheet S in order to ensure a sufficient amount of light in the width direction of the sheet S. The amount of light at both ends is increased. That is, the LED light source unit 61 increases the light amount of the LEDs 73 on both sides in the width direction among the plurality of LEDs 73 arranged in the width direction. In the present embodiment, the LED light source unit 61 increases the amount of light at both ends in the width direction of the sheet S, but is not limited to this configuration. The LED light source unit 61 may irradiate the irradiation light with a width larger than the width of the sheet S in order to ensure a sufficient amount of light in the width direction of the sheet S. That is, the LED light source unit 61 has a plurality of LEDs 73 arranged in the width direction so as to be larger than the sheet S.

  The condenser lens 62 is provided between the LED light source unit 61 and the transmission window 68, and is provided across the width direction of the sheet S while being supported inside the cover case 65. The condensing lens 62 is constituted by, for example, a rod lens having a circular cross section, and allows diffusion in the width direction of the sheet S, while condensing in the transport direction of the sheet S. That is, the condensing lens 62 is a lens having a different refractive index in a different direction, and specifically has a higher refractive index in the transport direction of the sheet S than the refractive index in the width direction of the sheet S. It is a lens. Further, the condenser lens 62 is disposed so that the focal point of the condensed irradiation light is positioned on the irradiation surface of the sheet S. In this embodiment, a rod lens is used as the condensing lens 62. However, the present invention is not limited to this, and a lens using surface refraction such as a cylindrical lens, a Fresnel lens, a spherical lens, or a convex lens may be used.

  Here, with reference to FIG. 6 and FIG. 7, the light quantity of the irradiation light irradiated from the LED light source part 61 via the condensing lens 62 is demonstrated. FIG. 6 is a graph showing the amount of irradiation light in the sheet transport direction. FIG. 7 is a graph showing the amount of irradiation light in the width direction of the sheet. In the graph of FIG. 6, the horizontal axis is the transport direction, and the vertical axis is the light quantity. In the graph of FIG. 7, the horizontal axis is the width direction, and the vertical axis is the light quantity.

  As shown in FIG. 6, the amount of light in the transport direction of the sheet S is the highest at the center in the transport direction, and rapidly decreases from the center in the transport direction toward both sides. This is because the irradiation light from the LED light source 61 is condensed in the transport direction by the condenser lens 62. As shown in FIG. 7, the amount of light in the width direction of the sheet S is such that the irradiation light emitted from each LED 73 overlaps in the width direction and complements in the width direction. At this time, the irradiation light from the LED light source unit 61 is allowed to diffuse in the width direction by the condensing lens 62, and therefore the irradiation light in the width direction is wider than the irradiation light in the transport direction. .

  As shown in FIG. 3, the condensing lens 63 condenses the reflected light reflected from the irradiation surface of the sheet S, and causes the collected reflected light to enter the light receiving unit 64. In addition, the condenser lens 63 is disposed so that the focal point of the collected reflected light is located at the light receiving unit 64. In this embodiment, the condensing lens 63 is used, but instead of this, a laminated lens in which a plurality of condensing lenses are laminated in the incident direction of the light receiving unit 64 may be used.

  As shown in FIG. 4, the light receiving unit 64 includes a plurality of light receiving elements 75 that are arranged side by side in the width direction without any gap. For this reason, the plurality of light receiving elements 75 are provided more than the plurality of LEDs 73. The light receiving unit 64 is disposed inside the cover case 65 and is provided on the opposite side of the blanket cylinder 33 with the LED light source unit 61 interposed therebetween. Specifically, since the light receiving unit 64 is provided inside the inclined surface 65b of the cover case 65, the light receiving unit 64 receives reflected light reflected at a reflection angle of 45 ° from the irradiation surface of the sheet S. And the light-receiving part 64 receives the irradiation light irradiated in one direction from the LED light source part 61 as reflected light through an irradiation surface.

  Here, the distance from the LED light source unit 61 to the irradiation surface of the sheet S is shorter than the distance from the irradiation surface of the sheet S to the light receiving unit 64. That is, by shortening the distance from the LED light source unit 61 to the irradiation surface of the sheet S, the diffusion of irradiation light irradiated from the LED light source unit 61 can be suppressed. The amount of irradiation light with respect to can be ensured.

  Accordingly, when the line sensor 50 at the irradiation position irradiates the irradiation light from the LED light source unit 61 toward the irradiation surface of the sheet S, the light is condensed by the condenser lens 62. Since the focusing lens 62 is focused on the irradiation surface of the sheet S, the irradiation light is irradiated on the irradiation surface of the sheet S while being condensed in the transport direction of the sheet S. Is done. The irradiation light condensed by the condenser lens 62 is irradiated perpendicularly to the irradiation surface of the sheet S through the transmission window 68. The irradiation light irradiated on the irradiation surface of the sheet S is reflected on the irradiation surface of the sheet S and becomes reflected light. Since the focal point of the condenser lens 63 is located at the light receiving unit 64, the reflected light that has passed through the condenser lens 63 enters the light receiving unit 64 in a condensed state. The light receiving unit 64 receives the reflected light reflected from the irradiation surface of the sheet S at a reflection angle of 45 °. At this time, the LED light source unit 61 irradiates irradiation light in one direction, and the light receiving unit 64 receives the irradiation light irradiated in one direction from the LED light source unit 61 as reflected light. In the sensor 50, the optical path from the LED light source unit 61 to the light receiving unit 64 is in one direction.

  Next, the control device 6 will be described with reference to FIG. FIG. 8 is a block diagram functionally showing the control system of the sheet-fed printing press according to the present embodiment. The sheet printer 1 maintains the print quality of the sheet S by controlling the printer body 5 by the control device 6 based on the printing state of the sheet S detected by the line sensor 50. Yes. That is, the control device 6 functions as a part of a quality management device that manages the quality of the printed state of the sheet S. The control device 6 includes a processing unit 80, a storage unit 81, and a display unit 82.

  The storage unit 81 can be configured by a volatile memory such as a RAM serving as a work area for executing various programs or the like, a non-volatile memory such as a ROM or a hard disk drive, or a combination thereof. The storage unit 81 is provided with a printed pattern data storage unit 85 and a sample pattern data storage unit 86.

  The printed pattern data storage unit 85 stores the printed pattern of the sheet S read by the line sensor 50 as printed pattern data. This print pattern data is obtained by converting the printing state of the sheet S into data, and relates to the dot area ratio, density, or color coordinate value (L, a, b) of each color (C, M, Y, K). Contains data.

  The sample picture data storage unit 86 stores sample picture data to be compared with the printed picture data. The sample pattern data is obtained by converting a pattern pattern printed on the sheet S into data, and is so-called plate making data used for producing a printing plate wound around the plate cylinder 32. That is, the control device 6 is connected to a plate making system 100 that manufactures a printing plate based on the sample picture data, and the plate making system 100 outputs the sample picture data to the control device 6. The control device 6 stores the sample pattern data input from the plate making system 100. Similarly to the printed pattern data, the sample pattern data includes data relating to the dot area ratio, density, or color coordinate value (L, a, b) of each color (C, M, Y, K). Note that the sample pattern data may be read from the line sensor 50 when the pattern printed on the sheet S is in an optimal printing state during the trial printing of the sheet S. The control device 6 compares the sample pattern data with the printed pattern data read by the line sensor 50 and performs density adjustment or quality inspection when the sheet S is printed.

  The processing unit 80 is configured by a CPU or the like that performs operations for executing various programs, and can execute various control processes based on various programs and various design data stored in the storage unit 81. Become. Here, the processing unit 80 includes a printing error determination unit 92, a density comparison unit 93, an ink key opening control unit 94, and a print defect determination unit 96.

  The printing error discriminating unit 92 compares the sample pattern data and the printed pattern data to determine the printing error of the printing plate wound around the plate cylinder 32. The printing plate error determination unit 92 performs such a comparison for a plurality of areas, and determines printing plate loading errors based on the overall match / mismatch. The determination result of the printing plate error determination unit 92 is output to the display unit 82 of the control device 6, and a warning is displayed on the display unit 82 when there is a printing plate loading error.

  The density comparison unit 93 compares the printed pattern data stored in the printed pattern data storage unit 85 with the sample pattern data stored in the sample pattern data storage unit 86, and calculates a density difference.

  The ink key opening degree control unit 94 controls the ink key opening degree adjustment unit 40 so as to adjust the opening degree of the ink key 39 according to the density difference calculated by the density comparison unit 93. The ink key opening control unit 94 adjusts the opening of the ink key 39 so that the density difference is eliminated by the ink key opening adjusting unit 40, thereby changing the ink supply roller 38 and the ink key 39, thereby supplying the ink supply amount. To change. The control result of the ink key opening control unit 94 is output to the display unit 82 of the control device 6, and the current ink key opening of the ink key 39 is displayed on the display unit 82.

  The print defect determination unit 96 compares the density difference or the parameter related to the density difference with a predetermined threshold value. Here, a defect that causes an abnormality in printing density is determined, such as when the ink is not applied where it should be applied, or when the pattern is crushed due to excessive ink. The control result of the print defect determination unit 96 is output to the display unit 82 of the control device 6, and a warning is displayed on the display unit 82 when there is a print defect.

  As described above, the control device 6 according to the present embodiment uses the printing pattern data read by the line sensor 50 to discriminate a printing plate application error, adjust the ink key opening, eliminate the density difference, and further print. Defects can be determined.

  Note that the control using the line sensor 50 is not limited to the above-described control, and for example, register control can be performed. The register control is a control for correcting a deviation of the printed pattern with respect to the sheet S. A registration mark is printed on the sheet S together with a printed pattern, and the line sensor 50 reads the registration mark printed on the sheet S. That is, the print pattern data includes data related to the register mark, and the sample pattern data includes data related to the register mark serving as a sample. And the control apparatus 6 discriminate | determines generation | occurrence | production of registration shift by comparing the registration mark of printing pattern data with the registration mark of sample pattern data. When the control device 6 determines that the registration error has occurred, the control device 6 corrects the registration error by appropriately adjusting the position of the plate cylinder 32 of the printing unit 12. Of course, when the registration mark is not in the picture, the registration deviation may be controlled on the basis of the picture portion where the registration deviation can be detected.

  As described above, according to the configuration of the present embodiment, the LED light source unit 61 can make the irradiation angle with respect to the irradiation surface of the sheet S vertical, and the LED light source unit 61 and the sheet S can be The distance from the irradiation surface can be made shorter than the distance between the irradiation surface of the sheet S and the light receiving unit 64. Thereby, since the distance from the LED light source unit 61 to the irradiation surface of the sheet S can be shortened, the diffusion of the irradiation light from the LED light source unit 61 can be suppressed as much as the distance can be shortened, and the LED light source unit 61 on the irradiation surface. The amount of light from can be increased. Moreover, since the condensing lens 62 can condense irradiation light to the conveyance direction of the sheet S, the light quantity from the LED light source part 61 in an irradiation surface can further be enlarged. On the other hand, the condensing lens 62 allows the irradiation light to be diffused in the width direction, and therefore, the LEDs 73a of the same kind among the LEDs 73a, 73b, 73c, and 73d arranged at a predetermined interval in the width direction. , 73b, 73c, 73d, both end portions of each irradiation light overlap each other in the width direction. For this reason, the irradiation light irradiated from each LED73a, 73b, 73c, 73d of the same kind is complemented over the width direction. For this reason, the number of LEDs 73 to be used can be reduced. At this time, the LED light source unit 61 irradiates irradiation light in one direction, and the light receiving unit 64 receives irradiation light irradiated in one direction from the LED light source unit 61 as reflected light. Since the optical path from the light source unit 61 to the light receiving unit 64 can be in one direction, the configuration of the line sensor 50 can be made compact. Further, when the configuration of the line sensor 50 becomes compact, the line sensor 50 can be disposed close to the impression cylinder 34 and the blanket cylinder 33. That is, since the distance between the impression cylinder 34 and the blanket cylinder 33 and the irradiation surface of the sheet S can be shortened, the LED light source 61 is a sheet sandwiched between the impression cylinder 34 and the blanket cylinder 33. Irradiation light can be irradiated to the sheet bottom edge of the sheet S with respect to the sheet S. As a result, even if the sheet S is separated from between the impression cylinder 34 and the blanket cylinder 33 and the paper bottom end of the sheet S is lifted, the gap between the impression cylinder 34 and the blanket cylinder 33 and the irradiation surface Since the distance is short, the influence of the floating of the sheet S can be reduced, and a decrease in detection accuracy related to the printing state of the sheet S can be suppressed.

  Furthermore, as shown in FIG. 3, the LED light source unit 61 can make the irradiation angle with respect to the irradiation surface of the sheet S vertical, and can suppress the diffusion of the irradiation light, so that the diffused irradiation light is applied to the nail portion. Irradiation can be suppressed, and generation of scattered light at the nail portion can be suppressed. Here, with reference to FIG. 9, the line sensor 105 having a configuration different from that of the present embodiment will be described, and the scattered light of the line sensor shown in FIG. 3 and the scattered light of the line sensor 105 shown in FIG. To do.

  FIG. 9 is a schematic configuration diagram showing a line sensor in the opposite direction to the optical path of the present embodiment. In this line sensor 105, the optical path from the LED light source unit 61 to the light receiving unit 64 of the line sensor 50 of this embodiment is in the reverse direction. That is, the light source unit 107 of the line sensor 105 irradiates the irradiation light so that the irradiation angle with respect to the irradiation surface of the sheet S is 45 °. The light receiving unit 108 of the line sensor 105 receives reflected light reflected from the irradiation surface of the sheet S at a reflection angle of 90 °.

  Therefore, when the line sensor 105 irradiates the irradiation light from the light source unit 107 toward the irradiation surface of the sheet S, the irradiation light is irradiated at an irradiation angle of 45 ° with respect to the irradiation surface of the sheet S. . The irradiation light irradiated on the irradiation surface of the sheet S is reflected on the irradiation surface of the sheet S and becomes reflected light. The light receiving unit 108 receives reflected light reflected at a reflection angle of 90 ° from the irradiation surface of the sheet S. At this time, the light source unit 107 irradiates irradiation light in one direction, and the light receiving unit 108 receives irradiation light irradiated in one direction from the light source unit 107 as reflected light. The light path from the light source unit 107 to the light receiving unit 108 is in one direction.

  Here, in the light source unit 107 shown in FIG. 9, the irradiation angle with respect to the irradiation surface of the sheet S is 45 °. For this reason, when the claw portions 34a and 34b of the impression cylinder 34 are on the upstream side of the irradiation direction with respect to the irradiation surface, a part of the irradiation light generated from the light source unit 107 with an irradiation angle other than 45 ° is part of the impression cylinder 34. The reflected light reflected by the claw portions 34a and 34b is likely to enter the light receiving portion 108. Further, another part of the irradiation light is easily reflected on the irradiation surface and incident on the light receiving unit 108. For this reason, since scattered light obtained by scattering irradiated light is likely to enter the light receiving unit 108, the line sensor 105 may cause a decrease in detection accuracy due to the influence of the scattered light.

  On the other hand, the LED light source 61 shown in FIG. 3 has an irradiation angle of 90 ° with respect to the irradiation surface of the sheet S. For this reason, even if the claw portions 34a and 34b of the impression cylinder 34 are located on the upstream side of the irradiation direction with respect to the irradiation surface, the irradiation light generated from the LED light source 61 with an irradiation angle other than 90 ° is It is difficult to go to the claw portions 34 a and 34 b of the 34, and it is difficult to enter the light receiving portion 64 after being reflected by the irradiation surface. For this reason, since it is difficult for the scattered light scattered by the irradiation light to enter the light receiving unit 64, it is possible to prevent the scattered light from entering the light receiving unit 64, and thus the line sensor 50 has a detection accuracy due to the influence of the scattered light. Can be suppressed, and the printing state of the sheet S can be suitably detected. Furthermore, since the LED light source unit 61 can be positioned on the blanket cylinder 33 side, the sheet S can be irradiated with irradiation light after the claw portions 34a and 34b have passed, and the irradiation light is emitted from the claw portions 34a and 34a. It can suppress that 34b is irradiated and scattered, and the fall of the detection accuracy which concerns on the printing state of the sheet S can be suppressed.

  Further, according to the configuration of the present embodiment, the LED light source unit 61 increases the amount of light at both ends of the sheet S in the width direction as compared with the amount of light at the center of the sheet S in the width direction. Can do. Thereby, when the width direction of the LED light source unit 61 is substantially the same as the width direction of the sheet S, the sheet S is obtained even if the LED light source unit 61 is not provided outside the sheet S in the width direction. By increasing the amount of light at both ends in the width direction, a decrease in the amount of light at both ends in the width direction of the sheet S can be compensated. For this reason, the line sensor 50 can suppress the fall of the detection accuracy by the light quantity fall.

  Further, according to the configuration of the present embodiment, when air is blown between the impression cylinder 34 and the blanket cylinder 33 in order to suppress the flapping of the bottom edge of the sheet S, the impression cylinder 34 Since the inclined surface 65b is widened, the blown air is not obstructed by the cover case 65, so that the air can be suitably introduced between the impression cylinder 34 and the blanket cylinder 33.

  Further, according to the configuration of the present embodiment, the cover case 65 can be rotated between the irradiation position and the maintenance position around the rotation shaft 70, so that maintenance work can be suitably performed. Become.

  Further, according to the configuration of the present embodiment, by providing the condensing lens 63, it is possible to increase the amount of reflected light incident on the light receiving unit 64, thereby suppressing a decrease in detection accuracy due to a decrease in the amount of light. Can do.

  In the present embodiment, the sheet printing machine 1 that performs single-sided printing has been described. However, the present invention is not limited to this configuration, and may be applied to a sheet printing machine that performs double-sided printing. In this case, it is preferable to provide a line sensor that detects the printing state of one printing surface of the sheet S and a line sensor that detects the printing state of the other printing surface of the sheet S. In this case, as the control using the line sensor, similarly to the above, the control device 6 determines the printing plate application error, adjusts the ink key opening to eliminate the density difference, and further determines the printing defect. Control, register control, etc. are executed. Note that the registration control is performed by executing registration control on one printing surface (front surface) of the sheet S and registration control on the other printing surface (back surface) of the sheet S. It is possible to align the printed patterns on the front and back of the.

DESCRIPTION OF SYMBOLS 1 Sheet-fed printing machine 5 Printer main body 6 Control apparatus 11 Paper feed part 12 Printing part 13 Paper discharge part 32 Plate cylinder 33 Blanket cylinder 34 Impression cylinder 35 Intermediate | middle cylinder 36 Ink apparatus 39 Ink key 40 Ink key opening adjustment part 50 Line sensor 52 Gap 55 Air nozzle 61 LED light source part 62 Condensing lens 63 Condensing lens 64 Light receiving part 65 Cover case 65b Inclined surface 68 Transmission window 70 Rotating shaft 73 LED
75 Light-receiving element 80 Processing unit 81 Storage unit 85 Print pattern data storage unit 86 Sample pattern data storage unit 92 Printing error determination unit 93 Density comparison unit 94 Ink key opening control unit 96 Print defect determination unit S Sheet

Claims (8)

A width direction of the printing sheet for detecting a printing state of the printing sheet sequentially fed from between the impression cylinder and the printing cylinder facing the impression cylinder while being held by a claw portion located on a peripheral surface of the impression cylinder A line sensor of a sheet-fed printing machine provided over
An LED light source unit in which a plurality of LEDs including at least R, G, and B emission colors are arranged side by side in the width direction at a predetermined interval;
Provided across the width direction so as to face the plurality of LEDs, and allowing the irradiation light emitted from the LED light source unit to diffuse in the width direction, the irradiation light is orthogonal to the width direction. A condensing lens that condenses in the transport direction of the printed sheet;
A plurality of light receiving elements larger than the plurality of LEDs are arranged side by side in the width direction, and receive reflected light reflected from an irradiation surface of the print sheet irradiated with the irradiation light condensed by the condenser lens. A light receiving unit,
The LED light source unit is provided on the printing cylinder side as compared with the light receiving unit, and irradiates the irradiation light in one direction so that an irradiation angle with respect to the irradiation surface is vertical,
The light receiving unit is provided on the opposite side of the printing cylinder across the LED light source unit, and receives the irradiation light irradiated in one direction from the LED light source unit as the reflected light through the irradiation surface. ,
The line sensor characterized in that a distance between the LED light source unit and the irradiation surface is shorter than a distance between the irradiation surface and the light receiving unit.   2. The line sensor according to claim 1, wherein the LED light source unit has a larger amount of light at both end portions in the width direction of the print sheet than a light amount at a center portion of the print sheet in the width direction.   The line sensor according to claim 1, wherein the LED light source unit irradiates the irradiation light so as to have a larger width than the printed sheet. A case that covers the LED light source unit, the condenser lens, and the light receiving unit;
The case has a facing surface facing the irradiation surface,
The opposing surface is an inclined surface that inclines so that the space between the opposing surface and the irradiation surface is widened on the downstream side in the conveyance direction of the printing sheet fed from between the impression cylinder and the printing cylinder. And
The light receiving portion is provided inside the inclined surface inside the case,
4. The line sensor according to claim 1, wherein the LED light source unit is provided between the printing cylinder and the light receiving unit inside the case. 5.   5. The apparatus according to claim 4, further comprising a rotation shaft that rotatably supports the case between an irradiation position where the irradiation surface is irradiated with the irradiation light and a maintenance position for performing maintenance. The described line sensor.   The light receiving side condensing lens which is provided over the width direction and condenses the reflected light to enter the light receiving unit. Line sensor. A line sensor according to any one of claims 1 to 6,
A quality control device comprising: a control device that controls a printing process for the print sheet based on a print state of the print sheet detected by the line sensor. A paper feeding device capable of supplying the print sheet;
A printing device that performs a printing process on the print sheet supplied from the paper feeding device;
The line sensor according to any one of claims 1 to 6, which detects a printing state of the print sheet after printing;
A paper discharge device for discharging the print sheet;
A sheet-fed printing press comprising: a control device that controls the printing process for the print sheet based on a print state of the print sheet detected by the line sensor.

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