Plate cassette loader for platesetter

#Plates are typically large substrates that have been coated with photosensitive or thermally-sensitive material layers. Depending on the type of plate, they can be sensitive or insensitive to ambient light. The plates are usually used in commercial printing operations. For large run applications, the substrates are fabricated from aluminum, although organic substrates, such as polyester or paper, are also available for smaller runs. Because of the composition, the plates can be somewhat heavy, especially in the context of a stack of relatively large plates.

#Computer-to-plate printing systems are used to render digitally stored print content onto these printing plates. Typically, a computer system is used to drive an imaging engine of a platesetter. The engine selectively exposes the surfaces of these plates. In a common implementation, the plate is fixed to the outside or inside of a drum and then scanned with a modulated laser source in a raster fashion.

#Typically, one of two different strategies is used to feed the plates to the imaging engine. In the simplest case, an operator manually places individual plates into a feeder that then conveys the plates through a feed port to the drum scanner. This approach, however, has some obvious drawbacks, since an operator must be dedicated to feeding the plates. Moreover, the printing system must be housed within a light-safe environment, if the plates being used have any sensitivity to ambient light. The alternative approach is to use a plate manager.

#In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:

#FIG. 1 is a side elevation showing the plate cassette loader in the load position and its relationship to the imaging engine of the platesetter, according to the present invention;

#FIG. 2 is a side elevation showing the plate cassette loader in an intermediate phase of operation where it is rotating the cassette to a feed position, according to the present invention;

#FIG. 1 shows a platesetter 10 with a plate cassette loader 100 comprising a cassette holder 110 and a cassette inverter 105, which have been constructed according to the principles of the present invention.

#In more detail, the platesetter 10 generally comprises an infeed port 16 that conveys plates to an imaging engine in the general region of 12. The plates are typically loaded onto an imaging drum of the image engine and exposed, typically in a raster fashion by a scanning laser. Plates are thereafter ejected through an outfeed port 18 to a finished plate location 20. Thereafter, the plates are typically transported for further processing including development.

#The plate cassette loader 100 generally comprises a cassette holder 110 and a cassette inverter 105.