Abstract: A line-scanning optical printer, which forms an image on a sensitized sheet (25) by projecting a linear light having a given width and length thereto while successively scanning individual lines in the direction of the width, comprises a casing (50) having light shielding properties and including a window portion for radiating the linear light to the outside, a light emitting element (60), which substantially functions as a point light source and is stored in the casing, an optical system (72, 71, 73) for guiding light from the light emitting element (60) as the linear light to the window portion, and a liquid crystal optical shutter (80) attached to the window portion.

Abstract: The production is described of unsaturated polyesters, which exclusively contain maleate groups in their main chain, by the ring-opening polymerization of epoxides, such as glycidyl ethers, glycidyl esters and olefine epoxides, with &agr;,&bgr;-unsaturated anhydrides, preferably such as maleic anhydride, both on their own and in admixture with other cyclic anydrides, in the presence of a Zn2+ carboxylate. The polyesters which are thus produced are characterized by high molecular weights and a narrow molecular weight distribution. Polymerization can be effected between 50 and 120° C., but is preferably effected between 60 and 90° C., either in the melt or in a solvent. Unsaturated reactive thinners, which after the addition of suitable radical initiators react thermally or photochemically with the polyesters to form lacquers, cast parts or fiber-reinforced composite materials, can also be employed as solvents.

Abstract: The present invention uses LEDs as the light source in a optical printer employing a line scanning method in which an image is produced by relative motion of the light to a photosensitive medium. LEDs are arranged on a mounting substrate with LED pairs, each pair being of the same color, disposed symmetrically as to the center point of the line. Similarly, the power supply lead wires for the LEDs are also disposed symmetrically. In mounting the components on the mounting substrate, a light-intercepting material is used for intercepting light from the side faces of the LEDs.

Abstract: The present invention employs LEDs and a liquid crystal shutter driven in synchronization with the position of the photosensitive paper, thereby eliminating image distortion even where the head of the optical printer apparatus is subjected to unanticipated load during scanning by the head. A rotary encoder (320) is provided on the rotating shaft of the motor (310) that drives the optical head (100), and the drive timing for the LEDs (110) and the liquid crystal shutter (150) is synchronized with the output of the rotary encoder.

Abstract: An optical printer apparatus exposes a sensitized sheet (500) to light from a light source (110), which is movable relatively to the sensitized sheet (500), with given timing in accordance with image data composed of pixels having a plurality of gradations that are linearly changeable from a minimum gradation of low color density to a maximum gradation of high color density. The distance for the exposure is adjusted for area gradation, whereby a gradated image is formed on the sensitized sheet (500). Further, change of the exposure distance, compared to change of the gradation, is not uniform throughout the range, and a non-linear relation is established between the changes.