Abstract: An apparatus for extracting and conveying a printing plate. The apparatus includes separation plates disposed at corners of a cassette accommodating at least printing plates. Air enters between an uppermost printing plate that is extracted and an underlying printing plate or an interleaf sheet, thereby separating the uppermost printing plate from the underlying printing plate or the interleaf sheet. Guide rails disposed above the cassette are parallel to a bottom of the cassette. Movable/rotatable bodies are disposed on the guide rails so as to be movable along the guide rails and be rotated about 180° within moving ranges, such that the uppermost printing plate is sent into an exposure section with an emulsion surface of the printing plate facing up.

Abstract: A sheet feeding method for plate-shaped members is disclosed. In a sucker unit, suction nozzles are move down from respective original positions toward a bottom plate of a cassette at a fixed speed, and time t1 until the bottom plate is detected by a contact sensor, and an amount by which the suction nozzles move, &Dgr;y, until the suction nozzles suction adhere to the bottom plate after the bottom plate is detected by the contact sensor are measured. Subsequently, separation positions of the suction nozzles with respect to the original positions are set based on an interval between the bottom plate of the cassette and separation plates, and an interval required by the photopolymer plate being bent between the suction nozzles and the separation plates at an appropriate curvature. Based on the result of the setting, the photopolymer plate is reliably taken out from the cassette.

Abstract: A pair of optical sensors are disposed above photopolymer plates and interleaf papers, which are alternately stacked with one another. These optical sensors basically have the same structure. However, the optical sensor is disposed so as to be inclined to an optical axis of reflected light, and therefore, a detection level of the optical sensor substantially becomes low. Accordingly, although the optical sensors each react to the reflected light from the photopolymer plate, the optical sensor does not react to the reflected light from the interleaf paper. As a result, it is determined whether the uppermost layer of the stack is the photopolymer plate or the interleaf paper. In a discriminating device of the present invention, general purpose optical sensors adapted to react to light having such a fixed intensity or greater, are used.

Abstract: During an initial setting period, if there is a tendency for a belt to move sideways due to tolerance when components are assembled in the initial setting, inclination in the axial direction of a driven roller can be changed after the components are assembled, to adjust degree of tension at both end portions in the transverse direction of the belt wound at a driven roller. Accordingly, the tendency for the belt to move sideways caused during assembly of the components can be corrected. Further, when there are changes over time (reduced elasticity of the belt, changes in the positioned state of rollers, or the like), sideways movement may occur during operation. However, in these cases, since a tapered auxiliary roller is attached at each of end portions in the axial direction of the rollers so as to be able to rotate relatively to the respective roller that is the base body thereof, when the belt moves sideways onto the auxiliary rollers the belt can be promptly returned to its original position.

Abstract: A pressure switch 302 is set in communication with suction cups 124 of a suction adherence conveying device 109 applied to an automatic exposure device. Further, a suction fan 126, which can approach and move away from a photopolymer plate 102 or an interleaf sheet 118 accommodated within a magazine 208, is set integrally with the suction cups 124. By utilizing the fact that degrees of vacuum of the suction cups 124 differ in accordance with materials to be suction-adhered, determination of a material to be suction-adhered is performed based on output signals of the pressure switch 302.

Abstract: A belt transmission mechanism has a crowned drive pulley, a crowned driven pulley, and a belt trained under tension around the crowned drive pulley and the crowned driven pulley. The crowned drive pulley and the crowned driven pulley are dimensioned to satisfy the equation:D2/D1=k.multidot.R1/R2where D1 is the diameter of the crowned drive pulley, D2 is the diameter of the crowned driven pulley, R1 is the radius of the crown of the crowned drive pulley, R2 is the radius of the crown of the crowned driven pulley, and k is a constant which is approximately 1. The belt transmission mechanism with the above drive and driven pulley dimensions can maintain its speed reduction ratio highly accurately even when the tension of the belt varies.