Browse Prior Art Database

XY Tablet for Array Scanning and Printing

IP.com Disclosure Number: IPCOM000088559D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 3 page(s) / 30K

Publishing Venue

IBM

Related People

Folchi, GA: AUTHOR [+5]

Abstract

The described system offers a solution to the problem of inexpensive high precision registration of adjacent bands of scanning and printing for images. In printing and scanning devices it is necessary to make a tradeoff on the length of the transducer array against other system parameters, e.g., mechanical precision, lens cost and support electronics. Systems are designed with array lengths ranging from a single transducer to ~4000 (full page at 480 picture elements (pels) per inch (ppi)). In the intermediate range, printing and scanning of bands on the order of 1/6 to 1" (40-240 elements at 240 ppi) is of interest. One of the key technical problems for graphics noncoded information (NCI) applications is precise band-to-band registration.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

XY Tablet for Array Scanning and Printing

The described system offers a solution to the problem of inexpensive high precision registration of adjacent bands of scanning and printing for images. In printing and scanning devices it is necessary to make a tradeoff on the length of the transducer array against other system parameters, e.g., mechanical precision, lens cost and support electronics. Systems are designed with array lengths ranging from a single transducer to ~4000 (full page at 480 picture elements (pels) per inch (ppi)). In the intermediate range, printing and scanning of bands on the order of 1/6 to 1" (40-240 elements at 240 ppi) is of interest. One of the key technical problems for graphics noncoded information (NCI) applications is precise band-to-band registration.

Normally, the paper is mounted on a cylindrical platen (as in a typewriter) and incremented with respect to the print/scan head which translates along the platen axis. Problems occur in achieving accurate band-to-band registration as a result of mechanical tolerances associated with accurate incrementing of the platen and as a result of paper slip-page even if accurate platen control is achieved.

This system involves the use of an X-Y tablet, including a technique for inexpensive implementation of accurate band-to-band registration. Other advantages of the approach are associated with flatbed document handling for dealing with documents which are wrinkled or creased, part of a book or magazine, or odd-sized. The basic configuration (Fig. 1) consists of a tablet 2 upon which the document rests and a traversal bar 4 which guides the scan/printhead 6 in the horizontal direction and which can be accurately incremented in the vertical direction. The vertical registration of the bar is achieved by a technique involving a pair of racks 8 and 10 extending vertically along each edge of the page and two short sections of identical rack 12 and 14 attached to the bar which engages the guide racks (Fig. 2). It has been found that the registration accuracy achievable using inexpensive racks is of the order of + or - 0.1 mil.

Fig. 2 illustrates a sc...