Raster image serial printer and method for operating same

摘要

A raster image serial printer in which a printing operation can be carried out using a buffer (13; 23) having as small a capacity as possible by altering the form of bit map data in proportion to the amount of the memory that can be used as an image buffer. The raster image serial printer includes a print data decision unit (11) for determining the type of input data, a buffer capacity decision unit (14) for determining the capacity of a buffer (13) in which raster image data is assembled, an image assembling unit (12) for assembling the image by determining the number of bits to be assembled corresponding to the available memory capacity, and a latch (15) for latching the image data assembled in the buffer (13) and null data obtained from a null data generator (16) for making up the deficiency. When the input data is raster image data and the capacity of an image buffer is small, the printing operation is carried out while the deficiency is made up by null data in such a way that bit map data lines fewer in number than the dot forming elements of a recording head are stored in the buffer.