Patent ID: 7821394
Filing Date: 2010-10-26
Classification: G01V

Abstract:
1. A penetration detecting apparatus having a muting function, comprising: a penetration detecting sensor for performing a detection of an object at a predetermined detection area; an alarm means for providing an alarm signal based on a result of the detection performed by the penetration detection sensor when the muting function is not activated; a signal receiver for receiving a first detection signal representing either a detection status or an absent detecting status of the object from a first sensor and a second detection signal representing either a detection status or an absent detecting status of the object from a second sensor; a muting starter for activating the muting function at a time of shifting of the second detection signal from the absent detecting status to the detection status after the first detection signal is shifted from the absent detecting status to the detection status; a muting timer for performing a comparison of continuous time when the muting function is activated within a predetermined period; a time differential watcher for recognizing a differential time between a time of shifting of the first detection signal from the absent detecting status to the detection status and the time of shifting of the second detection signal from the absent detecting status to the detection status, and for determining whether the differential time is within a predetermined criterion; and a muting terminator for terminating the activated muting function based on the comparison performed by the muting timer and a signal representing a passage of the object provided from a passage sensor when the differential time is not within the predetermined criterion, and for terminating the activated muting function based on a signal representing the passage of the object provided from the passage sensor when the differential time is within the predetermined criterion.