The Number Wheel

Abstract

A logical valuator device which provides interactive graphical input of numeric values is presented. This device, called the Number Wheel, was developed for interactive control of highly dynamic three-dimensional displays but is not limited to this use: It is a general purpose valuator device. The implementation of the Number Wheel described here is based upon a digitizer tablet as the physical input device. The character of the Number Wheel is best explained by developing an analogy with a hypothetical physical device. The Number Wheel can be thought of as a wheel which has a portion of its circumference, or tread, protruding through a slot on the surface of the tablet, somewhat like a giant thumb wheel. Each value in the desired range of the valuator is represented by a point on the circumference of the wheel with the value of the device at any given time being the point at the top of the wheel. The valuator is changed by putting the pen on the wheel where it protrudes through the tablet and moving it back or forth in the direction of rotation. Whenever the pen leaves the rim of the wheel while still moving, the Number Wheel maintains the same speed of rotation until the pen returns to the wheel in order to change or stop its movement.