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US 6,305,284 B1Granted
Method and apparatus for making an offset printing plate
AssigneeAsahi Kasei Kabushiki Kaisha
InventorsMiyoshi Watanabe, Masami Mochizuki
Life of this patent
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Abstract
The present invention concerns a plate making method of forming an image on a heat sensitive blank plate by a multichannel method using a plate making apparatus of an outer surface cylinder scanning type. A blank plate (400) is secured to the outer circumferential surface of a hollow cylinder (131). A laser beam (800) is irradiated from an optical head (150) onto the blank plate (400). The laser beam (800) is a beam group consisting of a plurality of infrared laser beams arranged in a line.
Claims14
A method of making an offset printing plate, comprising:
- a blank plate attaching step of winding a plate-shaped blank plate having a heat sensitive layer to which an image is formed thermally on a support around an outer circumferential surface of a cylinder with the heat sensitive layer being directed outward, thereby making the blank plate rotatable integrally with the cylinder;
- and
- an image forming step of irradiating a group of beams comprising a plurality of infrared laser beams arranged in line to the blank plate on the outer circumferential surface of the cylinder based on an image forming signal while rotating the cylinder, thereby forming an image in accordance with the image forming signal to the heat sensitive layer of the blank plate;
- wherein, in the image forming step, the group of beams in line are irradiated to a single area on the blank plate;
- and
- wherein irradiation conditions for the plurality of infrared laser beams comprising the group of beams are determined individually such that the temperature of the blank plate is made uniform within the single area in which the image is formed at once by the group of beams in line.
3 more elements
A method of making an offset printing plate, comprising:
- a blank plate attaching step of winding a plate-shaped blank plate having a heat sensitive layer to which an image is formed thermally on a support around an outer circumferential surface of a cylinder with the heat sensitive layer being directed outward, thereby making the blank plate rotatable integrally with the cylinder;
- and
- an image forming step of irradiating a group of beams comprising a plurality of infrared laser beams to the blank plate on the outer circumferential surface of the cylinder based on an image forming signal while rotating the cylinder, thereby forming an image in accordance with the image forming signal to the heat sensitive layer of the blank plate;
- wherein, in the image forming step, the group of beams in line are irradiated to a single area on the blank plate;
- and
- wherein a post treating step of irradiating UV-rays at a wave length of 200 to 400 nm to the heat sensitive layer of the blank plate is conducted after the image forming step.
3 more elements
An apparatus for making an offset printing plate, comprising:
- a cylinder having a rotational mechanism,
- a blank plate attaching mechanism for winding and securing a plate-shaped heat sensitive type blank plate to the outer circumferential surface of the cylinder,
- a cassette for keeping a plurality of blank plates,
- a blank plate supply mechanism for taking out the blank plates from the cassette and directing them to the cylinder,
- a laser generation device for generating a group of beams comprising a plurality of infrared laser beams arranged in line,
- a laser irradiation head having an optical system for focusing the group of beams comprising a plurality of laser beams irradiated from the laser generation device to a single area on the blank plate,
- an irradiation condition setting device for setting irradiation conditions on each of infrared laser beams based on an image forming signal and the position in the line such that the temperature of the blank plate is made uniform within the single area in which an image is formed at once by the group of beams in line, and
- a head moving mechanism for linearly moving the laser irradiation head along a line opposing in parallel with the rotational axis of the cylinder at a position spaced apart by a predetermined distance from the cylinder.
5 more elements
An apparatus for making an offset printing plate, comprising:
- a cylinder of a structure capable of winding and securing a plate-shaped blank plate around the outer circumferential surface,
- a rotational mechanism for the cylinder,
- a laser generation device for generating a group of beams comprising a plurality of infrared laser beams arranged in line,
- a laser irradiation head having an optical system for focusing the group of beams comprising a plurality of laser beams irradiated from the laser generation device to a single area on the blank plate,
- an irradiation condition setting device for setting irradiation conditions on each of infrared laser beams based on an image forming signal and the position in the line such that the temperature of the blanket plate is made uniform within the single area in which an image is formed at once by the group of beams in line,
- a head moving mechanism for moving the irradiation head along with a line opposing in parallel with the rotational axis of the cylinder at a position spaced apart by a predetermined distance from the cylinder,
- a UV-ray irradiation device for irradiating UV-rays at a wavelength of 200 to 400 nm to the heat sensitive layer of the blank plate, and
- a blank plate moving mechanism for detaching the blank plate from the cylinder and the directing the same to the UV-ray irradiation device.
5 more elements
Dependencies are inferred from the claim text.