Method and apparatus for correcting and adjusting digital image output

A method of correcting imaging errors in a digital imaging system, said system including an array of imaging devices, means for bearing a substrate to be imaged by the imaging devices, and means for causing relative movement between the imaging devices and the substrate-bearing means to effect a scan of the substrate by the imaging devices in a lateral series of adjacent longitudinal swaths, each of the swaths having a swath width and the imaging errors being due to a lateral and longitudinal offsets of at least one of said devices offset with respect to at least one other of said devices, the method comprising the steps of:

• a. selecting one of said devices as a longitudinal baseline device;
• b. selecting one of said devices as a lateral baseline device;
• c. causing each of said devices to image a plurality of swaths including a first swath;
• d. delaying or advancing imaging of each of the swaths for any of said devices having a longitudinal offset relative to the longitudinal baseline device by an amount of time corresponding to the offset;
• e. preventing any of said at least one of said laterally offset devices offset by a displacement having a magnitude greater than the width of one of said swaths from imaging the first swath until the lateral baseline device has imaged a number of swaths equal to a round-off of n to a nearest integer, where n corresponds to said magnitude, expressed in swath widths;
• f. after all of said devices have image at least the first swath, advancing the array a lateral distance of less than one said swath width and causing each of said devices to repeat a previous one of the swaths, thereby correcting lateral imaging errors by producing an overlap among swaths;
• and
• g. causing the devices to image successive swaths after said first swath until the substrate has been scanned.

A digital imaging system comprising:

• a. an array of imaging devices;
• b. means for bearing a substrate to be imaged by the imaging devices;
• c. means for causing relative movement between the imaging devices and the substrate-bearing means to effect a scan of a substrate by the imaging devices, each of the devices forming a series of laterally adjacent longitudinal imaging swaths including a first imaging swath, each of the swaths having a swath width;
• and
• d. control means for selectively causing the devices to discharge in an imagewise pattern during the scan;
• wherein the control means includes:
• e. means for delaying, for each of said devices laterally offset with respect to a baseline device by a displacement having a magnitude greater than one said swath width, the first imaging swath until the baseline device has imaged a number of swaths equal to a round-off of n to a nearest integer, where n corresponds to said magnitude, expressed in swath widths;
• f. means for causing the array to be advanced a lateral distance of less than one said swath width and causing all of said devices to repeat a previous one of the imaging swaths after all of the devices have imaged at least the first imaging swath, thereby producing an overlap among imaging swaths;
• and
• g. causing the devices to image successive swaths after said first swath until the substrate has been scanned.