Scanning brush and method of use

A scanning system comprising:

• a source of multiple beams;
• scan optics that sweeps the beams along a scanning direction of scan lines in an image plane, wherein at least one of the beams moves along an associated scan line with a non-uniform velocity;
• a modulator positioned to separately control intensities of the multiple beams, wherein each scan line is divided into a series of uniform size pixels, and the modulator controls an intensity for each pixel;
• and
• a timing generator coupled to provide a first signal to the modulator to indicate boundaries of the pixels in a scan line, the timing generator comprising:
• a look-up table containing pixel period values that correspond to the pixels in the scan line;
• a first counter that generates an index to the look-up table, wherein the first counter changes the index in response to the signal to the modulator indicating a boundary and in response to the index the look-up table outputs a pixel period value corresponding to the index;
• a second counter coupled to the look-up table, wherein for each pixel, the counter loads a first value from the pixel period value from the look-up table, counts for a period of time indicated by the first value, and asserts a second signal marking an end of the period, the first signal being derived from the second signal.

A scanning system comprising:

• a source of a scan brush including a first plurality of beams that in a single sweep forms a number b of scan lines that are uniformly spaced apart by a distance n;
• scan optics that sweeps the scan brush along a scanning direction of scan lines in an image plane;
• and
• an indexing system that moves the object relative to the scan brush by a distance m, wherein the distance m, the distance n, and the number b satisfy
• 3 m n = b q ,
• q being an integer have no factors in common with b;
• and

A method for printing comprising:

• forming a scan brush including a first plurality of beams that in a single sweep forms a number b of scan lines that are uniformly spaced apart by a distance n;
• scanning the scan brush along an object to expose a set of scan lines on the object;
• moving the object relative to the scan brush by a distance m, wherein the distance m, the distance n, and the number b satisfy
• 4 m n = b q ,
• q being an integer have no factors in common with b;
• and
• repeating the scanning and moving NS times to expose uniformly spaced scan lines on a region on the object, the uniformly spaced scan lines in the region being spaced apart by a distance less than the distance n.