48. Quality of lines and edges - inkjet swath alignment - 2011

48. Quality of lines and edges - inkjet swath alignment - 2011

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Slide No. 1 Improved Pen Alignment for Bidirectional Printing* Edgar Bernal Prof. Jan P. Allebach Prof. Zygmunt Pizlo Purdue University * Research supported by the Hewlett-Packard Company.
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Slide No. 2 Outline Motivation: why is accurate pen alignment important? Proposed approach 1. Imaging analysis tools 2. Psychophysical experiments Discussion
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Slide No. 3 Operation of an inkjet printer A carriage transports the pen back and forth across the page. The pen fires ink onto the surface of the page. Paper is advanced through the printer by a series of rollers driven by a stepper motor.
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Slide No. 4 Motivation •Main focus is on draft print modes (fast, single pass, bidirectional). •Accurate swath-to-swath alignment is essential for good print quality.
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Slide No. 5 The problem Typical dot shape, 15 ips, right to left swath Typical dot shape, 45 ips, right to left swath Typical dot shape, 45 ips, left to right swath • Dot shape depends on print speed and print directionality. • How does the human viewer perceive dot position when dot shape is asymmetric? • How does the human viewer perceive alignment when relationship between main dot/satellite is reversed from swath to swath? Tails and satellites appear more frequently at higher speeds
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Slide No. 6 Background on perception of misalignment: Vernier acuity Vernier acuity, the ability to detect offset between two vertical or horizontal lines, is in the order of 10 seconds of arc* ( 10 × 10 -4 in @ 10 in viewing distance). Want to determine whether Vernier acuity is affected by changes in dot shape and size. Retinal image size is measured by the angle subtended by the object. ______________________ * Regan, David. Human Perception of Objects. 2000.
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Slide No. 7 Outline Proposed approach: measuring misalignment and classifying dots. Psychophysical tests: constant stimuli and signal detection. Discussion of results.
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Proposed approach Design tools to measure alignment of printouts. Analyze the structure of dot formation on the
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This note was uploaded on 02/19/2012 for the course ECE 638 taught by Professor Staff during the Fall '08 term at Purdue University-West Lafayette.

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48. Quality of lines and edges - inkjet swath alignment - 2011

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