Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
193 words
In an inspection system for web materials that includes electronic means responsive to means scanning the web for detecting a nonuniform appearance condition of the web, said electronic means providing a low signal-to-noise ratio signal having AC and DC components, the improvement comprising: a first DC extractor circuit coupled to said electronic means for extracting the DC component of said signal and providing an AC signal output; a low pass filter connected to said fist DC extractor circuit for permitting a preselected band of frequencies from said AC signal output representative of said nonuniform web appearance to pass through; a rectifier connected to said low pass filter, said rectifier producing a DC signal from said AC signal output, said DC signal having an RMS value representative of the said nonuniform web appearance; an averaging filter connected to said rectifier for producing a time-averaged signal from said DC signal level produced from said AC signal output, the persistence and magnitude of said nonuniform appearance condition being characterized by a cHange in amplitude of said time-averaged signal; and means for recording said time-averaged signal and signalling when said time-averaged signal exceeds a preselected threshold value.
Claim 2
Dependent Claim
193 words
In an inspection system for web materials that includes electronic means responsive to means scanning the web for detecting a nonuniform appearance condition of the web, said electronic means providing a low signal-to-noise ratio signal having AC and DC components, the improvement comprising: a first DC extractor circuit coupled to said electronic means for extracting the DC component of said signal and providing an AC signal output; a low pass filter connected to said fist DC extractor circuit for permitting a preselected band of frequencies from said AC signal output representative of said nonuniform web appearance to pass through; a rectifier connected to said low pass filter, said rectifier producing a DC signal from said AC signal output, said DC signal having an RMS value representative of the said nonuniform web appearance; an averaging filter connected to said rectifier for producing a time-averaged signal from said DC signal level produced from said AC signal output, the persistence and magnitude of said nonuniform appearance condition being characterized by a cHange in amplitude of said time-averaged signal; and means for recording said time-averaged signal and signalling when said time-averaged signal exceeds a preselected threshold value.
Claim 3
Dependent Claim
19 words
The system defined in claim 1, including a second DC extractor circuit connected between said filter and said rectifier.
Claim 4
Dependent Claim
86 words
The system as defined in claim 2, each of said first and second DC extractor circuits comprising: an amplifier; a follower; a charging circuit connected between the amplifier and follower, said charging circuit including a capacitor connected between the output of the amplifier and the input of the follower; a resistor connected between the input of the follower and ground; and an electronic switch connected from the input of the follower to ground, said switch being operated in timed relationship with said low signal-to-noise ratio signal.
Claim 5
Dependent Claim
70 words
The system as defined in claim 1, said system being a flying spot inspection system for web materials that includes a radiation source, a means for traversing a beam of radiation from said source in a scan across the web, said electronic means being responsive to said beam of radiation in the transmission or reflection mode with respect to said web for detecting a nonuniform appearance condition of the web.
Claim 6
Dependent Claim
20 words
The system as defined in claim 1, including a selectable bias amplifier connected between said rectifier and said averaging filter.