Abstract: A method for forming plate characters in a half-tone gravure platemaking process being characterized in that a laser beam moved so that the laser beam is intermittently irradiated onto a light sensitive material and a plate character is formed on the light-sensitive material by exposure. The character thus formed is made up with a character frame portion and a character fill portion surrounded by the character frame portion, the character frame portion being formed by a plurality of intermittently arranged groove-form cells each having a predetermined length and a width which can prevent flow of ink when ink is applied by wiping the plate surface with a doctor, and the character fill portion being formed by dot-form cells which have a shadow-portion dot percentage.

Abstract: A method for forming plate characters in a half-tone gravure platemaking process in which a laser beam intermittently irradiates a photosensitive material, thus forming plate characters therein as a result of exposure by the laser beam. The outline portion of each character is made up of continuous groove-form cells and inner portion of the character (the filled portion) is made up of independent dot-form cells corresponding to the dot percentage of a shadow portion or with island-form projections to the extent that ink flow (running) does not occur when the cells are filled with ink as a result of the plate surface being wiped by a doctor blade. The outline portion of each character is made up of groove-form cells having a narrow width without causing ink flow (running) when the cells are filled with ink as a result of the plate surface being wiped by a doctor blade.

Abstract: An optical beam splitter which splits a single light into a plurality of split beams including a plurality of transparent plates of uniform thickness arranged in a stack with fully reflective films coated on the transparent plates at both ends of the stack and semi-reflective films coated on the remaining transparent plates in the stack. The reflectivities of the individual semi-reflective films gradually increase from one end to the other in the stack and a beam entering the stack is first entirely reflected by the back-end fully reflective film, then passes through the semi-reflective films while being reflected partially by the semi-reflective films, and then finally entirely reflected by the front-end fully reflective film so that a single beam is split into a plurality of parallel split beams.

Abstract: A method for correcting the path of a gas laser beam by reflecting the beam with a first mirror, further reflecting such reflected beam with a second mirror, and then reflecting the beam reflected by the second mirror with a first half-mirror, passing such reflected beam through a condensing lens and then reflecting it with a second half-mirror. The beam passing through the first half-mirror is received by a first photodiode, and the beam passing through the second half-mirror is received by a second photodiode, and prior to the use of the gas laser, deviation of the beam passing through the first half-mirror is detected via the first photodiode to eliminate such beam deviation via actuators, and deviation of the beam passing through the second half-mirror is detected by the second photodiode to eliminate such beam deviation via another actuator, so that the path of the beam reflected by the second half-mirror is corrected to a given path.

Abstract: An optical beam splitting method and optical beam splitting/modulating method for recording halftone plate images on a recording material through controlling a light exposing device by image signals obtained by photoelectric manipulation of an original image. Two light beam splitters are used so that a single light beam can be split into a plurality of split light beams which are lined up in two rows and shifted by one-half pitch with respect to each other and then modulated in multi-channel ultrasonic modulators, one row of the light beams being modulated with a delay without causing crosstalk. The number of split beams to be modulated is approximately doubled compared to a conventional system, and the size of the dots on the recording material can be decreased so that the image resolution is remarkably improved.

Abstract: An optical beam splitter including a prescribed number of stacked transparent parallel plates whose thicknesses are uniform to a high degree of precision, the back surface of the transparent parallel plate which is the farthest from the side at which light beam that is to be split enters is coated with a totally reflective film, while the back surfaces of all of the remaining transparent parallel plates are coated with different semi-reflective film whose respective reflectivities gradually increase and the coating region of the totally reflective film and semi-reflective films are positioned in an oblique arrangement which is struck by the light beam traveling obliquely through the interiors of the transparent parallel plates.

Abstract: The invention is concerned with an apparatus for automatically attaching and detaching cassette-type rolls, which is suited for plating peripheral surfaces of the roll having shaft, and particularly for plating peripheral surfaces of a photogravure roll, with copper or chromium. The conventional apparatus which horizontally chucks both ends of a photogravure roll and which also spins the roll, could be adapted to the cassette-type hollow rolls, but could not be adapted to the cassette-type rolls having shaft. According to the apparatus for attaching and detaching cassette-type rolls of the present invention, the current-carrying supporters are exchanged depending upon the type of the roll to be treated, and the leak-proof caps are made up of moving caps that slide on the outer side of the spindles and exchange caps that are located between end surfaces of the roll and the moving caps.