Patent Document ID: 4425588
Application ID: 06230034

Base Claim:
1. In an apparatus for processing signals in the form of digital words, comprising (a) filtering means having an input terminal for receiving a sequence of input digital words, and an output terminal for supplying a sequence of filtered words; (b) selection means having input and output terminals, said selection means input terminal being connected with the output terminal of said filtering means, said selection means being operable to omit predetermined words from the sequence thereof and for supplying a reduced number of digital words to said selection means output terminal; and (c) output means connected with said selection means output terminal for acting upon the reduced number of words; the improvement which comprises (d) monitoring means connected with the input terminal of said filtering means for determining if the input digital words have a characteristic similar to the filtered words; and (e) bypass means operable by said monitoring means when said monitoring means determines that an input digital word has a characteristic similar to a filtered word for causing the input digital word to bypass said filter means and thereby remain in the non-altered condition.

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Claim 2:
2. Apparatus as defined in claim 1, wherein said monitoring means includes means for producing digital outputs which are functions of the digital input words, means for combining said digital outputs, and means for comparing selected ones of said combined digital outputs with a reference signal, thereby to determine whether the input digital words have a characteristic similar to filtered words.