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: An apparatus for feeding printing plate precursors is provided with a detecting sensor for detecting a position of a separation plate mounted on a cassette accommodating printing plate precursors, and a plate surface detecting sensor for detecting an uppermost plate of printing plate precursors stacked in the cassette. A relative position of the separation plate with respect to suction nozzles of a suction frame of the apparatus for feeding plates is controlled constant.

Abstract: A suction transport device capable of reducing manufacturing cost due to reduction of the number of suction mechanisms by which one of photopolymer plates accommodated in a magazine is taken out is attained. Also separability when the printing plate is taken out is improved, thus improving reliability of the suction transport device. Since, among suckers and suction fans, those located at positions corresponding to the widthwise direction ends of the printing plates are movable in the widthwise direction, and separating plates are movable in the same direction. When one of the printing plates of a different size is to be taken out, the leading end corner portions of the printing plate can always be curved at a fixed curvature, and separability is improved. Further, there is no need to increase the number of suckers thus decreasing cost.

Abstract: An apparatus for feeding printing plate precursors is provided with a detecting sensor for detecting a position of a separation plate mounted on a cassette accommodating printing plate precursors, and a plate surface detecting sensor for detecting an uppermost plate of printing plate precursors stacked in the cassette. A relative position of the separation plate with respect to suction nozzles of a suction frame of the apparatus for feeding plates is controlled constant.

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.