Patent ID: 11861433
Assignee: BROTHER KOGYO KABUSHIKI KAISHA
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. An image forming apparatus, comprising:
a photosensitive drum;
a semiconductor laser having N laser emitters, N being a natural number larger than or equal to two;
an incident optical system configured to convert light emitted from each laser emitter to a beam;
a polygon mirror configured to deflect and cyclically scan each beam from the incident optical system;
a scanning optical system configured to form on the photosensitive drum N beam spots by N beams deflected by the polygon mirror, each beam spot scanning along a scan line on the photosensitive drum to form a beam image along the scan line for one cycle, any neighboring two beam spots in the N beam spots having centers with a center-to-center distance of the neighboring two beam spots separated by M scan lines, M being a natural number larger than or equal to two;
an optical sensor configured to detect a beam which is deflected to output a detection signal for each cycle;
a page memory configured to store raster image data including a plurality of sets of line data;
a line memory configured to store the sets of line data read from the page memory, the line memory having storage areas and addresses identifying respective ones of the storage areas; and
a memory controller configured to perform:
for each cycle based on the detection signal outputted from the optical sensor,
reading adjacent sets of line data for scan lines from the page memory, the adjacent sets of line data for scan line successively arranged on the photosensitive drum;
writing the adjacent sets of line data for scan lines to the storage areas identified by a plurality of successive addresses among the addresses of the line memory;
selecting addresses identifying storage areas storing unadjacent sets of line data for N scan lines having non-successive two scan lines separated by M scan lines on the photosensitive drum; and
outputting the unadjacent sets of line data stored in the storage areas identified by the selected addresses to the N laser emitters.