Precision Scanner-Plotter for Image Conversion.
Abstract
The Precision Scanner-Plotter (DSP-35) was developed to provide an improved means of converting photographic images from transparent film to computer-compatible signals and vice versa. The system was specifically designed to operate under automatic control of an IBM-1800 computer in a dust environment. The design specifications were extremely rigid in dimensional accuracy, requiring performance characteristics equal to the most complex microdensitometers. As the program progressed, it became apparent that the contractual objective of producing a low-cost system was in direct conflict with meeting the operational specifications. The dimensional accuracies were met by utilizing moire' fringe-displacement sensors on each axis of the X-Y positioning stage. The high-speed axis, utilizing a dc servo motor, was able to achieve the desired processing rate of 1000 picture elements per second. The low-speed axis motion was provided by a two-speed clutch, gear and stepper motor mechanism. Line resolutions of 2 microns to 1024 microns were achieved with an absolute uncertainty of 0.4 microns between any two picture elements within a 35-mm picture frame. Repeatability was measured to be within 0.2 microns (considerably beyond the design objective). The 0.1% linearity and 60-dB signal-to-noise ratio over a 0 to 2 density range also were met. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1970
- Accession Number
- AD0887844
Entities
People
- Donald R. Weber
- James Gilbert Tisue