Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Coarse/ Fine Positioning Mechanism in a Display System

IP.com Disclosure Number: IPCOM000049926D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 3 page(s) / 44K

Publishing Venue

IBM

Related People

Beausoleil, WF: AUTHOR [+2]

Abstract

The traditional use of a graphics tablet is for digitizing graphic information into a digital computer. The tablet can also provide a positioning and location function used for generating or selecting a graphic entity on a graphic display screen. The latter function is becoming more popular because of recent tablet cost reductions and because the tablet, when used in this manner, competes favorably with other types of graphic input mechanisms, such as trackball, light pen, selector pen, mouse, thumb wheel, etc. The positioning function is typically accomplished by direct control of the tablet stylus and the cursor on the graphic display screen. The cursor is controlled by a stream of X-Y coordinate pairs as the tablet stylus or other tablet cursor device is moved on the tablet.

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

Coarse/ Fine Positioning Mechanism in a Display System

The traditional use of a graphics tablet is for digitizing graphic information into a digital computer. The tablet can also provide a positioning and location function used for generating or selecting a graphic entity on a graphic display screen. The latter function is becoming more popular because of recent tablet cost reductions and because the tablet, when used in this manner, competes favorably with other types of graphic input mechanisms, such as trackball, light pen, selector pen, mouse, thumb wheel, etc. The positioning function is typically accomplished by direct control of the tablet stylus and the cursor on the graphic display screen. The cursor is controlled by a stream of X-Y coordinate pairs as the tablet stylus or other tablet cursor device is moved on the tablet. The stylus sampling rate is high enough to ensure smooth movement of the cursor on the screen regardless of how fast the stylus is moved. The cursor normal movement is directly proportional to the stylus movement. Fast cursor movement to the target is achieved at the expense of fine positioning accuracy, and vice versa.

The following technique provides for both "coarse" positioning and "fine" positioning of the display cursor, using a tablet stylus. It provides the user with fast cursor movements to his target and, once in the target vicinity, provides sensitive control of the cursor for smooth and accurate positioning. There is no cursor movement between the "coarse" and "fine" mode change. This has the advantage of requiring only a very small tablet and does not require any precise calibration or tablet accuracy to provide this function. Operation

In the "coarse" mode the position of the tablet stylus relative to the center of the tablet is scaled up such that a small mo...