| 摘要 |
<p>An apparatus for automatically sensing televiewing distance to determine whether or not a televiewer is standing within a predetermined potentially harmful distance in front of a television set by making use of the elapsed time difference between an ultrasonic pulse generated and emitted from a transmitter located on the television set and which is then reflected from a televiewer located in front of the television set. The reflected pulse is then received by an ultrasonic wave receiver also located on the television set and in the event that the televiewer stands within the predetermined distance for a time longer than is required, for example, to make a manual adjustment to the television set, a signal is generated which deactivates the video portion of the television set until such time that the televiewer moves to a safe distance away from the set beyond the predetermined potentially harmful distance at which time the video portion is again reactivated.</p> |
