The distance sensor

In addition to being able to sense the Upoint remote's orientation, sensing the distance to the display forms another integral part of the invention. Depending on the implementation of the cursor-grabbing procedure, the sensor needed to measure the appropriate distances can be either a laser-distance sensor or an ultrasonic distance sensor. 

The advantage of a laser distance sensor is that the initial setup procedure to find the display's position, size and orientation can be performed from anywhere in the room, and consists of simply pointing to two opposite diagonal corners (the '2-click setup'). Since laser distance sensors are capable of sensing distance along a very well defined line, the combination of measuring both the orientations of two pointing lines, as well as the distances to the display corners along these lines furnishes the system with all the information needed. The disadvantage, of course, is that laser-distance sensors are relatively expensive and bulky.

The advantage of an ultrasonic sensor is that it is relatively compact and inexpensive. The disadvantage is that the setup procedure to find the display's position, size and orientation consists of three measurements (the '3-click setup'), and has to be performed with the user standing in front of the screen. The first 2 of these three measurements constrain the orientation of the display, allowing the system to calculate which point on the display lies closest to the user. The third measurement then uses the ultrasonic distance sensor to ascertain the distance to the screen, from which the size and position of the display can be calculated.

Contact us at through the Feedback page with questions or comments about this web site.
Last modified: July 11, 2007