Price labeling system with floating zero reference

In a price labeling system which includes a weight-responsive transducer having an analog output signal which is highly linear over a predetermined weight range, and conveyor means for transiently causing a succession of articles within said weight range to act upon said transducer whereby said transducer produces a first analog output signal immediately prior to the time an article acts thereon and a second analog output signal while an article acts thereon, the difference between said first and second analog output signals indicating to a high degree of accuracy the gross weight of the article associated with such signals, the improvement which comprises:

• an analog-to-digital converter and amplifier means connecting said transducer to said analog-to-digital converter for causing said converter to produce respective first and second digital outputs corresponding to said first and second analog output signals in which the difference between said first and second digital outputs is a multiple m of said gross weight of an article, where m is much larger than one;
• and
• processing means connected with said analog-to-digital converter for computing the gross weight of an article from said first and second digital outputs.

In a weighing system, the combination of:

• conveyor means for transporting a succession of articles and scale means having a weight-responsive member upon which each of said articles is transiently rested, said scale means producing an analog output signal whose change in magnitude represents weight acting thereon;
• amplifier and converter means connected with said scale means to produce digital output signals expanded by a factor m compared with the magnitudes of the normal unexpanded analog output signals of said scale means;
• computer means connected to said amplifer and converter means for receiving digital output signals from said amplifier and converter means corresponding to laden scale member and unladen scale member weights for each article, for subtracting such digital signals and for dividing the result by said factor m to produce a highly accurate measure of gross article weight for each article.

In a weighing system, the combination of:

• conveyor means for transporting a succession of articles and scale means having a weight-responsive member upon which each of said articles is transiently rested, said scale means producing an analog output signal whose magnitude is proportional to weight acting thereon plus an offset;
• amplifier and analog-to-digital converter means connected with said scale means to produce digital output signals whose range is expanded by a factor m compared with the range of the normal, unexpanded analog output signals of said scale means;
• computer means connected to said analog-to-digital converter means for receiving digital output signals from said converter corresponding to laden scale member and unladen scale member weights for each article, for subtracting such digital signals and for dividing the result by said factor m to produce a highly accurate measure of gross article weight for each article.

In a weighing system as defined in claim 14 including a visual display mechanism connected with said computer means for displaying net weight of each article, said computer means being provided with article tare weight entry.