Method and apparatus for writing imageable material using multiple beams

A system for writing imageable material using multiple beams, said system comprising:

• an imaging device configured for generating N beams, wherein N is at least four;
• a controller configured for
• preparing subsequent patterns each having Y rows of N pixel locations, said subsequent patterns including a first and a second pattern;
• wherein the first and the second pattern overlap with each other in an overlap area consisting of O columns and Y rows of pixel locations, wherein O is at least two and smaller than N;
• selecting for each row i of said first pattern Mi1 pixel locations;
• selecting for each row i of said second pattern Mi2 pixel locations;
• wherein said selecting is such that at least one of the following conditions is fulfilled:
• (1) said Mi1 pixel locations of said first pattern are selected such that, for a row i, at least one selected pixel location thereof is separated from an adjacent selected pixel location by at least one non-selected pixel location located in the overlap area;
• and said Mi2 pixel locations of said second pattern are selected such that, for said row i, said non-selected pixel location of the first pattern is selected in the second pattern;
• wherein different rows of the first pattern contain selected pixel locations in different columns of the overlap area;
• and
• (2) said Mi1 pixel locations of said first pattern are selected such that, the number Mi1 is different for at least two different rows and such that any non-selected pixel location of the first pattern is selected in the second pattern;
• wherein the controller is configured for controlling said imaging device for writing simultaneously, for each row i, said Mi1 selected pixel locations by moving the N beams relative to said imageable material in a fast scan direction;
• for next moving said N beams relative to said imageable material in a slow scan direction over (N-O) pixel locations;
• and for then writing simultaneously, for each row i, said Mi2 selected pixel locations by moving the N beams relative to said imageable material in the fast scan direction;
• and
• wherein the controller is configured to select for each row i, Mi1 at random or according to an irregular pattern from values in a range between N−2*O and N, wherein any pixel locations located in an area of the first pattern which does not overlap with adjacent patterns, are always selected.

A system for writing imageable material using multiple beams, said system comprising:

• an imaging device configured for generating N beams, wherein N is at least four;
• a controller configured for
• preparing subsequent patterns each having Y rows of N pixel locations, said subsequent patterns including a first and a second pattern;
• wherein the first and the second pattern overlap with each other in an overlap area consisting of O columns and Y rows of pixel locations, wherein O is at least two and smaller than N;
• selecting for each row i of said first pattern Mi1 pixel locations;
• selecting for each row i of said second pattern Mi2 pixel locations;
• wherein said selecting is such that at least one of the following conditions is fulfilled:
• (1) said Mi1 pixel locations of said first pattern are selected such that, for a row i, at least one selected pixel location thereof is separated from an adjacent selected pixel location by at least one non-selected pixel location located in the overlap area;
• and said Mi2 pixel locations of said second pattern are selected such that, for said row i, said non-selected pixel location of the first pattern is selected in the second pattern;
• wherein different rows of the first pattern contain selected pixel locations in different columns of the overlap area;
• and
• (2) said Mi1 pixel locations of said first pattern are selected such that, the number Mi1 is different for at least two different rows and such that any non-selected pixel location of the first pattern is selected in the second pattern;
• wherein the controller is configured for controlling said imaging device for writing simultaneously, for each row i, said Mi1 selected pixel locations by moving the N beams relative to said imageable material in a fast scan direction;
• for next moving said N beams relative to said imageable material in a slow scan direction over (N-O) pixel locations;
• and for then writing simultaneously, for each row i, said Mi2 selected pixel locations by moving the N beams relative to said imageable material in the fast scan direction;
• and
• wherein, for performing the writing, a total power is available for the N beams, and wherein the controller is configured to control the powering during the writing of the first pattern and the second pattern, respectively, such that more power is made available per beam compared to a situation where the total power would be divided over N beams.