Abstract: A printer control apparatus and an algorithm for determining the peak instantaneous speed of a substrate through a thermal ink jet printer and a printer apparatus are disclosed herein. The printer includes a dryer module, a print head module, and a controller. The method includes determining the tolerable peak instantaneous speeds of the substrate through the print head and dryer modules, which by their sequential nature, operate out of phase from one another. The lower of the two speeds is then selected as the optimum instantaneous speed of the substrate through the printer. A controller in the printer carries out methods disclosed herein.

Abstract: A printer control apparatus and an algorithm for determining the peak instantaneous speed of a substrate through a thermal ink jet printer and a printer apparatus are disclosed herein. The printer includes a dryer module, a print head module, and a controller. The method includes determining the tolerable peak instantaneous speeds of the substrate through the print head and dryer modules, which by their sequential nature, operate out of phase from one another. The lower of the two speeds is then selected as the optimum instantaneous speed of the substrate through the printer. A controller in the printer carries out methods disclosed herein.

Abstract: An image input terminal (IIT) with automatic document handler for feeding documents to be scanned into registered position on the IIT platen. The IIT includes a pair of multi-element scanning arrays with cooperating scan lamp and optics on a movable carriage disposed in scanning relationship with the platen. Analog image signals generated by the scanning arrays are initially processed in separate channels and then combined into a serial stream. The stream of analog image signals may optionally be thresholded or screened to provide binary level image signals or converted to multi-bit gray scale. A control system including microprocessor provides timing and control signals for synchronizing operation of the scanning carriage, document handler, and image signal reading and processing together with electronic crossover between arrays to avoid loss of data, automatic signal gain and deletion of bad image signals or pixels.

Abstract: An adaptive thresholder for processing image pixels. A portion of the image pixel line or lines is examined and the maximum and minimum pixels in the line portion determined. The maximum and minimum pixels are differenced, and the resulting difference signal compared to a constant representing the minimum desired change in background level. Where the difference signal is larger, a new threshold is thereafter used.To determine the new threshold level, the difference signal is multiplied by a factor representing the amount of change in threshold for a given event and the result subtracted from the previously determined maximum pixel. The subtracted output is brought within predetermined maximum and minimum threshold constraints to provide the new threshold.