Process for the formation of images on printing form having ferroelectric material layer
AssigneeMAN Roland Druckmaschinen AG
InventorsRobert Weiss, Alfred Hirt
Life of this patent
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Abstract
A printing form and process relating to the formation of images on the printing form. The printing form includes a ferroelectric layer (1) on which photoferroelectric effect is used to polarize or depolarize the layer to form the image to be printed in the layer (1). The printing form may also include a layer which is neither ferroelectric nor has the function of a photoconductor which adjoins the ferroelectric layer 1. In this instance, the photoelectric effect is used to form the image to be printed on the ferroelectric layer.
Claims13
A process of forming images on a printing form comprising a first layer of ferroelectric material having a threshold frequency for triggering the photoelectric effect comprising the steps of:
- positioning said first layer between a first electrode covering an entire side surface of the first layer and a light-transparent image forming electrode arranged on at least a portion of an opposite side surface of the first layer;
- applying an electric field between the electrodes that is of a magnitude less than a coercive field strength of the non-irradiated first layer;
- irradiating a portion of the first layer from the opposite side surface through the light-transparent electrode with light radiation of a frequency above the threshold frequency for initiating the photoelectric effect in the first layer, which generates charge carriers from the first layer;
- polarizing the printing form in accordance with the image to be formed with the charge carriers generated by the photoelectric effect;
- and
- removing the light-transparent electrode from the opposite side surface of the first layer whereby the first layer is now ready for printing.
Dependencies are inferred from the claim text.