Defect inspection apparatus

Claim 2

Apparatus for detecting clusters of defects in a web comprising: a. means for scanning the said web and producing, in time relationship with said scanning, a train of signals, each of which signals is representative of a defect in said web, b. accumulator means adapted to receive serially the aforesaid train of defect representative signals in the same time relationship in which thy occur, c. means cooperative with said accumulator means respectively for increasing the accumulation of said accumulator means for each signal applied to said accumulator means, and for decreasing the accumulation in proportion to the time spacing between signals applied to said accumulator means, d. means for producing a reference accumulation and for comparing said reference accumulation with said accumulation of said accumulator means, and e. means cooperative with both said means for producing a reference accumulation and with said accumulator means for producing an output signal when the accumulation of the accumulator means is greater than the said reference accumulation.

Claim 3

The apparatus of claim 1 including means for adjusting the relative amounts that the accumulation of said accumulator means is increased ad decreased for given defect signals and signal spacings.

Claim 4

In a web inspection system of the type including: a. means for repeatedly scanning a web and, in response to discrete defects in said web, producing signals representative of such discrete defects, and b. means for receiving said signals and registering defects in response to sets of discrete signals representative of adjacent web defects, the improvement comPrising: a. accumulating means, b. means, cooperative with said means for receiving said signals and said accumulating means, for increasing and decreasing the accumulation of said accumulating means during each scan of said web respectively in response to discrete defect signals which do not occur in sets thereof, and in proportion to the spacings between said defect signals which do not occur in sets thereof, c. means for providing a reference accumulation, and d. means for comparing the said reference accumulation with the accumulation of said accumulating means and producing an output signal when the reference accumulation is the lesser of the two accumulations.

Claim 5

In a web inspection system of the type including: a. means for repeatedly scanning a web and, in response to discrete defects in said web, producing signals representative of such discrete defects, and b. means for receiving said signals and registering defects in response to sets of discrete signals representative of adjacent web defects, the improvement comPrising: a. accumulating means, b. means, cooperative with said means for receiving said signals and said accumulating means, for increasing and decreasing the accumulation of said accumulating means during each scan of said web respectively in response to discrete defect signals which do not occur in sets thereof, and in proportion to the spacings between said defect signals which do not occur in sets thereof, c. means for providing a reference accumulation, and d. means for comparing the said reference accumulation with the accumulation of said accumulating means and producing an output signal when the reference accumulation is the lesser of the two accumulations.

Claim 6

The system improvement of claim 3 including means, cooperative with said means for increasing and decreasing the accumulation of said accumulating means, for adjusting the relative amounts that the accumulation of said accumulating means is increased and decreased respectively in response to said discrete signals and said signal spacings.

Claim 7

The system of claim 3 wherein: a. said means for scanning and producing signals is comprised of a plurality of signal-processing circuits each cooperative with a respective widthwise portion of said web, b. said means for receiving signals and registering defects is comprised of a plurality of signal-storing means, each cooperative with a respective signal-processing circuit, for producing a defined defect representative signal output in response to a predetermined number of input signals received thereby during a predetermined number of scannings of its respective web portion, each said signal-storing means including means for clearing itself when the said predetermined number of scannings of its respective web portion are unproductive of a defined defect representative signal, and c. said means cooperative with said means for receiving signals is comprised of respective means adapted to receive said signals cleared from said signal-storing means, said respective means adapted to receive said cleared signals being cooperative with said accumulating means to apply serially thereto said signals cleared from said signal-storing means.

Claim 8

The system of claim 6 including means cooperative with said accumulating means for increasing the amount of the accumulation of said accumulating means, for each signal applied serially to said accumulating means, by an amount different than the amount by which said accumulation is decreased in response to signal spacings.

Claim 9

The system of claim 5 (a) wherein said means for receiving signals cleared from said signal storing means is a shift register the respective stages of which are adapted to receive and store respective cleared signals corresponding to respective portions of the web, and (b) wherein said system includes means for so shifting the signals stored in said register into said accumulating means that as each stage registering a stored signal is cleared of its signal the accumulation of said accumulating means is increased, and as each register stage not storing a signal is cleared, the accumulation of said accumulating means is decreased.

Claim 10

The system of claim 7 including means for modifying the amounts that said accumulations are respectively and discretely increased and decreased.