Method of recording images

DETAILED DESCRIPTION In accordance with the present invention, a method of recording an image on a record medium in which the image comprises a number of laterally interleaved first patterns comprises (1) deriving a second pattern formed by a plurality of the first patterns and/or portions of the first patterns whereby the image comprises a plurality of lines of the second patterns in the same orientation and which are not laterally interleaved; and, (2) causing relative movement between the record medium and an exposing beam or beams whereby the exposing beam(s) scans the record medium and is repeatedly controlled to reproduce the second pattern on the record medium such that the image is recorded on the record medium.
We have recognised that due to the repetitive nature of the final image it is possible to derive from the resulting image a second pattern formed by a plurality of the first patterns and/or portions of the first patterns which is repeated throughout the record medium in the same orientation.
The advantage of this is that only the second pattern needs to be stored and repeatedly accessed by repeatedly scanning in the same series of scan lines without any changes in the order of access of data from the store being required.
In the case of colour printing, the "image" referred to may comprise a colour separation so that in this case the method will be repeated with a plurality of record media and corresponding images, one for each colour component.
The record medium may comprise a printing member such as a gravure cylinder or a radiation sensitive film.
Step (1) of the method is most conveniently achieved by manual inspection of the image on for example a monitor.
The second pattern can then be defined by an operator using conventional image modifying techniques.
The invention is particularly applicable to a method of preparing a set of printed substrates, this method comprising preparing at least one printing member by using, at least as an intermediate step, a method according to the invention; printing a composite substrate with the or each printing member; and dividing the composite substrate into a set of identical subsidiary substrates, whereby each subsidiary substrate is printed with the image