Abstract: An image obtained by shrinking an original image in a row direction is halftoned, and this halftone dot image is enlarged in the row direction and recorded at double speed. In order to determine a threshold value of a threshold matrix used for halftoning an image, prepared is a matrix space in accordance with writing positions used for actual recording of an image. In the matrix space, writing elements are set alternately with non-writing elements both in the row direction and in a column direction. In the matrix space, turn-on numbers are allocated to all the writing elements in avoidance of the non-writing elements. Then, in accordance with the turn-on numbers, respective threshold values for the writing elements are determined. By shrinking the threshold matrix in the row direction with omission of the non-writing elements, a threshold matrix for double speed is obtained.
Abstract: In a method and a device to sort pixel data in a print data stream, a data sorting memory is used configured so that it can be written per column and read per row. The pixel data are entered per column into the data sorting memory in the order of the incoming print data stream. Via the per-row readout the pixel data are re-sorted into an order suitable to control the print head. The sorting can thereby take place in only one write process and one read process.
Abstract: The present invention enables the accurate management of the total number of spotting counts for each spotting pin. An IC chip is installed on the spotting pin to allow the IC chip to accumulate spotting-count information, and during each spotting time the information is loaded up and displayed.
Abstract: An ink density closed loop control system for an ink ribbon of an impact printer having a reservoir roller formed of an ink absorbent material with at least one or more channels within the reservoir roller fluidly connected to a pump and ink supply. A transfer roller can contact the reservoir roller for imparting ink to the ink ribbon. A sensor senses the relative amount of ink on the print ribbon and an electrical drive responsive to the sensor drives the pump for a flow of ink to the one or more channels. The sensor can sense ink on different segments of the ribbon and, with two or more channels in the reservoir roller can distribute ink to two or more segments of the reservoir roller depending upon the ink sensed at a particular segment of the ribbon. A further enhancement of this invention provides a multi-viscosity ink to compensate for changes in ambient temperature conditions.
Type:
Grant
Filed:
March 12, 2003
Date of Patent:
February 24, 2004
Assignee:
Printronix, Inc.
Inventors:
Dennis R. White, Jeng-Dung Jou, Lihu Chiu, Gordon B. Barrus, Y. Grant Chang