Original Publication Date: 1978-Jul-01
Included in the Prior Art Database: 2005-Feb-21
BACKGROUND. Raster patterns of uniformly spaced lines permit a transducer or array of transducers to scan all portions of an area on a surface. The simplest example is the uniform rectangular array (Fig. 1) for scanning a picture to be transmitted by voice communication. Another example is a slanted raster in which a rotating head (helical) traces across a magnetic tape (Fig. 2).