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US 4,047,007 AGranted
Clocked digital counting system
AssigneePitney Bowes Inc.
InventorsDaniel F. Dlugos, Flavio M. Manduley
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AssigneePitney Bowes Inc.
InventorsDaniel F. Dlugos, Flavio M. Manduley
Estimating the term…
A system for processing cyclic signal pairs generated by an optical transducer to provide an accurate measurement of the displacement of one member with respect to a reference is suitable for determining weight by measuring spring scale tare deflection. The system includes a pair of comparator Schmitt trigger circuits for shaping pulse waveform signals. The pulse signals are processed by fully clocked digital circuits including edge discriminators to generate multiple count pulses which are processed by combination logic for direction determination. Further processing includes sign determination (positive-negative) and zero identification circuits to provide up and down pulses which are filtered and fed to up/down counter stages. Counter stage information is decoded for feedback control and processing logic indication. The zero identification circuit facilitates an unambiguous zero reference indication by skipping one count at zero to provide a display sign change indication on either side of zero prior to incrementing display counts to better define true zero as an edge or line between successive displays rather than as a zone. In an alternate embodiment, zero transition indicators are provided by feeding the count pulses directly to an updown counter and utilizing the most significant counter bit to invert the counter outputs upon a transition through actual zero.
A system for processing cyclic waveforms generated as a function of the change of a bidirectionally variable parameter whose change is to be measured with respect to a reference, the system comprising digital wave shaping means, the digital wave shaping means receiving the cyclic waveforms and in response thereto providing a pair of shaped digital waveforms, clock means, the clock means providing a pulsed timing signal the frequency of which is greater than the maximum frequency of the cyclic waveforms, sensing means, the sensing means receiving the shaped waveforms and the timing signal and in response thereto determining the direction of a variation of the parameter and providing one series of pulses indicative of a variation in one direction and another series of pulses indicative of a variation in an opposite direction, counting means disposed in the system and coupled to the sensing means to receive either one of said series of pulses and the timing signal and in response thereto being adapted to add the pulses of the one series or to subtract the pulses of the other series to provide signals indicative of a measure of the varation in the parameter and processing means electrically connected within the system for receiving said signals and in response thereto providing an indication of the change of the bidirectionally variable parameter with respect to the reference, whereby reliable noise insensitive processing is provided.
A spring scale adapted to measure the weight of a load as a function of the deflection from a fixed reference of a tare adapted to carry the load, the scale comprising means operatively interconnecting the scale tare and the reference and adapted to generate an optical cyclic pattern, the generating means including means moving the pattern as a function of the scale tare deflection from a no load position, optoelectronic transducer means, the pattern being projected upon the transducer means, the transducer means generating a pair of cyclic waveforms as a function of the deflection of the tare, and a system for processing the cyclic waveforms to provide a determination of the weight of a load carried by the tare, the system including digital wave shaping means, the digital wave shaping means receiving the cyclic waveforms and in response thereto providing a pair of shaped digital waveforms, clock means, the clock means providing a pulsed timing signal the frequency of which is greater than the maximum frequency of the cylic waveforms, sensing means, the sensing means receiving the shaped waveforms and the timing signal and adapted to sense the direction of the tare movement and to provide one series of pulses indicative of movement in one direction and another series of pulses indicative of movement in an opposite direction, counting means coupled to the sensing means to receive either one of said series of pulses and the timing signal and in response thereto being adapted to add the pulses of the one series or to subtract the pulses of the other series to provide signals indicative of the measure of tare movement, and processing means receiving said signals indicative of the measure of tare movement and adapted to provide a load weight determinative indication corresponding to the steady state tare deflection.
Dependencies are inferred from the claim text.