Abstract: A laser light source has a plurality of semiconductor lasers arranged in a direction intersecting a primary scanning direction X. The semiconductor lasers are arranged in such a positional relationship that each semiconductor laser is located upstream, in the primary scanning direction X, of a different semiconductor laser located adjacent thereto and downstream thereof in a direction in which air is blown from an air blowoff pipe.

Abstract: When rotating a recording drum at low speed, air is jetted from air jet ports toward a point of irradiation, in a direction to diffuse a gas generating from an image recording medium upstream with respect to a direction of rotation of a recording drum. An air curtain approximately semicircular about the point of irradiation is formed upstream thereof with respect to the direction of rotation of the recording drum. As a result, the gas can hardly diffuse from the point of irradiation upstream with respect to the direction of rotation of the recording drum. The gas is collected from a gas suction opening. Thus, the gas is reliably prevented from contacting the image recording medium having an image recorded thereon.

Abstract: An image recording apparatus (1) causes a recording head (20) to move through a distance corresponding to one half of the recording width of the recording head (20) in a sub-scanning direction each time a recording drum (10) makes one rotation. This, light emitting devices (23, 24) record two line data in advance, and thereafter following light emitting devices (21, 22) record the same line data repeatedly at the same position. This increases the energy of laser light beams given to a recording position on a printing plate (P) to accomplish the recording of an image with reliability. The recording speed is not extremely decreased because not all light emitting devices (21 to 24) are used to make the repeated recordings at the same position on the printing plate (P). Further, the construction of optical systems and driving systems in the image recording apparatus is not complicated.

Abstract: Positioning of a printing plate in an image recorder is performed by the same method used for punching positioning holes for printing press in the printing plate. Specifically, the positioning for image recording is performed with reference to an edge of the printing plate on the same side as the edge of the printing plate used as a reference for punching the positioning holes for printing press. When the positioning for punching the positioning holes for printing press is performed with reference to the central position of the printing plate, the central position of the printing plate is detected based on a measured width of the printing plate, and the positioning for image recording is carried out with reference to the central position. Consequently, an image recorded on the printing plate by the image recorder and the positioning holes for printing press in the printing plate always have the same positional relationship.

Abstract: Positioning of a printing plate in an image recorder is performed by the same method used for punching positioning holes for printing press in the printing plate. Specifically, the positioning for image recording is performed with reference to an edge of the printing plate on the same side as the edge of the printing plate used as a reference for punching the positioning holes for printing press. When the positioning for punching the positioning holes for printing press is performed with reference to the central position of the printing plate, the central position of the printing plate is detected based on a measured width of the printing plate, and the positioning for image recording is carried out with reference to the central position. Consequently, an image recorded on the printing plate by the image recorder and the positioning holes for printing press in the printing plate always have the same positional relationship.

Abstract: An image recording system for setting processing contents related to image recording processing on the basis of the types of color components employed for printing data is provided. A donor sheet roll stored in an image recorder is rendered exchangeable in an intermediate stage of image recording, and recording conditions as to all recordable color components and the storage state of rolls are previously registered in a table. A control part of the image recorder compares/collates information of color components on which color separation data are obtained in a raster image processor with the roll storage state and determines necessariness/unnecessariness of roll exchange, for presenting an exchange object and requesting exchange to an operator if necessary. Thus, a proof image finished approximately to a regularly output image from a regular press can be obtained without increasing the number of rolls stored in the image recorder, so far as inks used in regular press and corresponding rolls are present.