| 摘要 |
<p>Printing apparatus in particular for performing multicolour printing operations has a ribbon shift mechanism (Figure 2 and 3) for selectively interposing different transversely spaced portions of a print ribbon 23 between a print head 14 and platen (not shown). The print head 14 is of the impact type and probably, although not necessarily, of the type which moves along the platen to define a print row. When colour printing is required, a ribbon having a plurality of longitudinally extending stripes of different colours transversely spaced across its width is used. Selection of required portions of colours of the ribbon is performed by moving the head 14 to preselected positions along the print row to engage, for example, a camming mechanism (including cam 21 and follower 28) which moves the shift mechanism the required amount to make the selection. Selection of the ribbon portion or colour is by program control and in the case of colour printing, the range of colours is increased by superimposed printing of the available colours on the print ribbon.</p> |
