CAN PRINTING APPARATUS AND CAN INSPECTION DEVICE

• US 20160229198A1
• Filed: 09/22/2014
• Published: 08/11/2016
• Est. Priority Date: 09/24/2013
• Status: Active Grant

• Current Assignee: I. Mer Co., Ltd., Nippon National Seikan Co., Ltd. (Toyo Seikan Group Holdings, Ltd.)
• Original Assignee: I. Mer Co., Ltd., Nippon National Seikan Co., Ltd. (Toyo Seikan Group Holdings, Ltd.)
• Inventors: IZUME, Masayuki
• Granted Patent: US 9,862,204 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B41F 13/14 with means for displacing the cylinders
• CPC Class Codes: B41F 17/22 by rolling contact
• CPC Class Codes: B41F 31/12 adjustable for regulating supply
• CPC Class Codes: B41F 31/14 Applications of messenger or other moving transfer rollers
• CPC Class Codes: B41F 33/0045 for automatically regulating the ink supply
• CPC Class Codes: B41F 33/0081 Devices for scanning register marks
• CPC Class Codes: B41P 2233/13 Pre-registering
• CPC Class Codes: B41P 2233/51 for colour quality control
• CPC Class Codes: B41P 2233/52 for registering
• CPC Class Codes: G01N 21/909 in opaque containers or opaque container parts, e.g. cans, tins, caps, labels
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10

Abstract

An image processor 53 processing taken images includes an image inspection means 54 for inspecting whether printing is performed properly as compared with a master image by using the image of the entire can taken by a first camera, a density measurement means 55 for measuring densities in designated positions for respective colors also by using the image of the entire can taken by the first camera, and a printing misalignment value measurement means 56 for measuring misalignment values with respect to set positions of printing misalignment inspection marks printed on an opening-side end portion of a can for respective colors by using the image of the opening-side end portion of the can taken by the second camera.

Claims

1. A can printing apparatus comprising:

a printer having plural plate cylinders for printing different colors and performing printing to cans;

a can inspection device performing inspections of print states of the cans; and

a controller changing printing conditions of the printer based on inspection results of the can inspection device.

2. The can printing apparatus according to claim 1,

wherein an ink supply device of the printer is provided with plural ink transfer rollers divided in a length direction of a inkwell roller so as to be close to the inkwell roller forming an inkwell,

each ink transfer roller is configured to be individually switched between a transfer position where the ink transfer roller contacts the inkwell roller and a non-transfer position where the ink transfer roller is separated from the inkwell roller,

a controller of the ink supply device transfers ink by switching the position of a required ink transfer roller at transfer timings of given intervals, and controls a rotation angle of the inkwell roller made from the contact to the inkwell roller until the separation from the inkwell roller in each ink transfer roller to thereby control a contact length between the ink transfer roller and the inkwell roller,

the can inspection device includes a can rotation device rotating cans, a can imaging device taking images of cans and an image processor processing taken images,

the image processor includes a density measurement means for measuring densities of images printed on cans for respective colors as well as for predetermined places corresponding to respective ink transfer rollers and outputting the densities to the controller of the ink supply devices, and

the controller of the ink supply devices adjusts the contact length between each ink transfer roller and the inkwell roller for each color based on respective density values outputted from the density measurement means of the can inspection device.

3. The can printing apparatus according to claim 2,

wherein density measurement places corresponding to the number of products between the number of plate cylinders to be used and the number of ink transfer rollers to be used are set in the density measurement means, and

density differences with respect to densities of a master image are measured in respective density measurement places.

4. The can printing apparatus according to claim 1,

wherein the can inspection device includes a can rotation device rotating cans, a can imaging device taking images of cans and an image processor processing taken images,

the image processor has a printing misalignment value measurement means for measuring misalignment values with respect to set positions of printing misalignment inspection marks printed on a can, and

the printer has a registration device performing registration of the plate cylinder automatically based on the printing misalignment values measured by the can inspection device.

5. The can printing apparatus according to claim 4,

wherein respective plate cylinders of the printer are arranged to print inspection marks used for detecting printing misalignment values of respective plate cylinders on an opening side end portion of the can.

6. The can printing apparatus according to claim 4,

where the registration device includes an axial direction moving means for moving the plate cylinder in the axial direction and a circumferential direction moving means for moving the plate cylinder in the circumferential direction,

the axial direction moving means has an axial direction moving member supported so as not to rotate and so as to move in the axial direction by a housing and moving in the axial direction integrally with a plate cylinder shaft,

an axial direction drive means moving the axial direction moving member includes a first rotation shaft supported so as not to rotate in the axial direction, a first female screw member supported so as not to rotate and screwed to a male screw portion provided in the first rotation shaft and a first motor driving the first rotation shaft,

the circumferential direction moving means is attached to the plate cylinder shaft so as to integrally rotate and so as to relatively move in the axial direction and engaged with a helical gear provided so as not to move in the axial direction, having a circumferential direction moving member which moves the plate cylinder shaft in the circumferential direction by being moved in the axial direction,

a circumferential direction drive means moving the circumferential direction moving member includes a second rotation shaft supported so as not to rotate in the axial direction, a second female screw member supported so as not to rotate and screwed to a male screw portion provided in the second rotation shaft and a second motor driving the second rotation shaft,

a controller controlling the first motor adjusts an axial direction position of the plate cylinder by driving the first motor in accordance with a printing misalignment value of a can in a height direction in the printing misalignment value measurement means,

a controller controlling the second motor adjusts a circumferential direction position of the plate cylinder by driving the second motor in accordance with a printing misalignment value of a can in a circumferential direction in the printing misalignment value measurement means.

7. The can printing apparatus according to claim 4,

wherein an ink supply device of the printer is provided with plural ink transfer rollers divided in a length direction of a inkwell roller so as to be close to the inkwell roller forming an inkwell,

each ink transfer roller is configured to be individually switched between a transfer position where the ink transfer roller contacts the inkwell roller and a non-transfer position where the ink transfer roller is separated from the inkwell roller,

a controller of the ink supply device transfers ink by switching the position of a required ink transfer roller at transfer timings of given intervals, and controls a rotation angle of the inkwell roller made from the contact to the inkwell roller until the separation from the inkwell roller in each ink transfer roller to thereby control a contact length between the ink transfer roller and the inkwell roller,

the image processor of the can inspection device further includes a density measurement means for measuring densities of images printed on cans for respective colors as well as for predetermined places corresponding to respective ink transfer rollers and outputting the densities to the controller of the ink supply devices, and

the controller of the ink supply device adjusts the contact length between each ink transfer roller and the inkwell roller for each color based on respective density values outputted from the density measurement means of the can inspection device.

8. A can inspection device comprising:

a rotation device rotating cans;

an imaging device taking images of rotating cans; and

an image processor processing taken images,

which is provided in a can printing apparatus, performing inspections of print states of the cans and feeding back inspection results to the can printing apparatus,

wherein the imaging device includes a first camera taking an image of the entire can and a second camera taking an image of an opening-side end portion of the can,

the image processor includes an image inspection means for inspecting whether printing is performed properly as compared with a master image by using the image taken by the first camera, a density measurement means for measuring densities in designated positions for respective colors by using the image taken by the first camera, and a printing misalignment value measurement means for measuring misalignment values with respect to set positions of printing misalignment inspection marks printed on the opening-side end portion of the can for respective colors by using the image taken by the second camera.

9. The can inspection device according to claim 8,

wherein the rotation device includes a vertical drive side rotating shaft driven by a motor, a vertical driven side rotating shaft rotating integrally with the drive side rotating shaft, a cylindrical holding member attached concentrically to the driven side rotating shaft so as to hold a can and an encoder detecting a rotation of the drive side rotating shaft, and

the drive side rotating shaft and the driven side rotating shaft face each other in the axial direction in a state of being positioned in a vertical direction, and magnets applying attracting forces to each other are provided to a lower end portion of the drive side rotating shaft and an upper end portion of the driven side rotating shaft, thereby allowing the drive side rotating shaft and the driven side rotating shaft to rotate integrally.

10. The can inspection device according to claim 8,

wherein an image capturing operation by the imaging device includes a step of previously setting an angle between a designation mark and an image capturing start position from the designation mark,

a step of finding the designation mark position by turning the can,

a step of calculating the image capturing start position based on the found designation mark, and

a step of capturing an image for one turn from the image capturing start position.