Reliance Electric Company

Edward G Pryor

Richard C Loshbough

Donivan L Hall

Roger B Williams, Jr

Gerald D Robaszkiewicz

A scale is disclosed which includes a digital display unit for conveying information. A display verification method and system are employed for determining whether a plurality of information conveying segments forming the indicators of the display unit are properly conveying information. Individual segments of the display unit are operated under control of a microprocessor. Segment status determining circuitry determines the operative status of each of the segments by sequentially monitoring a voltage drop indicative of the current passing through an LED comprising that segment. The status determining circuitry produces status information which is stored in the microprocessor memory and compared with data indicative of the information the display should convey if it is properly functioning. If the comparison indicates that one of the segments is not properly conveying the information, warning messages are displayed which indicate maintenance procedures are required. If all segments are correctly displaying information, the verification procedure is repeated.

Digital display verification

The invention relates to a scale system which employs a microcomputer forming an integral part of the analog to digital conversion means in which the microcomputer controls the sequence of operations for performing the conversion, accumulates and stores digital data derived during the conversion of the analog signal and combines and processes that data to provide the digital output data resulting from the conversion, all in addition to performing other scale functions. The invention relates to an improved multicapacity weighing and computing digital scale having a triple slope analog-to-digital conversion means. The analog weight signal is integrated for a time interval which is fixed for a given scale capacity range which would generate substantially the same integrator output level in response to a full capacity weight signal for the selected scale capacity as would be generated by a full capacity weight for all other scale capacities. In accordance with the invention, the time interval during which the first reference DC source is integrated is extended beyond the detection of the crossover of the integrator output with its reference level. The invention also provides an improved weight filtering arrangement which enables the full advantage of the improved converter to be obtained. The invention further provides for the tracking of the net zero indication by modification of the stored tare weight data by a predetermined amount to decrease the absolute value of the net weight in response to the net weight being within a preselected weight range.

Digital scale

The invention relates to a scale system which employs a microcomputer forming an integral part of the analog to digital conversion means in which the microcomputer controls the sequence of operations for performing the conversion, accumulates and stores digital data derived during the conversion of the analog signal and combines and processes that data to provide the digital output data resulting from the conversion, all in addition to performing other scale functions. The invention relates to an improved multicapacity weighing and computing digital scale in which switch means are provided to change the weight indication from pounds to kilograms and visa versa at any time either before or during a weighing operation. Provision is made to also convert all the weight limits and any stored tare weight. In addition, the unit price and total price or value display is either cleared or else converted from price per pound to price per kilogram and the total price recomputed.

Improved electronic apparatus for weighing and computing the value from the weight and price per unit weight, for each of a plurality of successive weighing operations. An integrated circuit microcomputer is supplied with the article weight from a load cell and an analog-to-digital converter. The price per unit weight is supplied from a manual keyboard. The microcomputer includes as an arithmetic logic unit, data registers and sequence controller which is programmed to correct for scale errors, to check for no motion of the scale, to compensate the measured gross weight for any tare weight, to check various interlocks, and to compute an article value for each successive weighing. Null or zeroing and tare interlocks, checks, and safeguards are provided to reduce the possibility of fraud.

Digital scale with antifraud features

This invention relates to an improved digital weight measuring and computing apparatus with automatic zero correction which automatically corrects the zero indication of the apparatus. The weight measuring apparatus comprises a scale which employs a load cell and strain gauge to develop an analog voltage representing the weight on the scale. An analog-to-digital converter is then employed to change the analog voltage into a digital representation of the load on the scale. The digital converter provides a digital indication in addition to the digital indications employed to indicate the weight on the scale. The additional digital indication represents fractions of the least weight increment indicated of the weight on the scale. The additional digital indication is then employed to control the generation of a zero correction factor and this factor is then combined with the weight indications from the scale to indicate the correct weight of articles placed on the scale. The corrected weight in combination with the unit price of the article placed on the scale is then employed to compute the value of the article on the scale.

Digital weight measuring and computing apparatus with automatic zero

Improved electronic apparatus for weighing, computing a value and printing a label showing the weight, the price per unit weight and the computed value of each of a plurality of successive articles. A microcomputer is supplied with the article weight from a load cell scale and with the price per unit weight either from a manual keyboard or automatically from a commodity plate in a label printer. Tare weight is entered through a plurality of switches, each of which represents a different tare weight. When one of the tare switches is actuated, a timer is started. If a second tare switch is then pushed before a predetermined time interval is measured by the timer, the tare weight represented by the two switches are added together to obtain the total tare weight. After the system corrects for zero error, checks for scale motion, compensates for the total entered tare weight and checks various interlocks, the microcomputer computes an article value and causes a label to be printed. A digital indicator is provided for displaying the net article weight obtained from the measured gross article weight less the zero error correction factor and the total entered tare weight.

Scale with manual tare entry

Improved electronic apparatus for weighing, computing a value and printing a label showing the weight, the price per unit weight and the computed value of each of a plurality of successive commodities. An integrated circuit microcomputer is supplied with the article weight from a load cell scale and with the price per unit weight either from a manual keyboard or automatically from a commodity plate in a label printer. The microcomputer includes an arithmetic logic unit, data registers and a sequence controller which is programmed to cause the microcomputer to correct for scale errors, to check for no motion of the scale, to compensate the measured gross weight for any tare weight, to check various interlocks, to compute an article value and to cause a label to be printed for the article. Input data to the microcomputer and output data from the microcomputer is multiplexed through interface circuitry. Weight data from the microcomputer is supplied to a digital indicator and weight, price per unit weight and value data from the microcomputer is supplied to the printer. The keyboard includes a lock switch which must be manually actuated after new price data is supplied to the microcomputer to enable the microcomputer to supply the calculated value data for the weighed commodities to the printer.

Value computing scale

Improved apparatus for weighing and computing a value for articles. An integrated circuit microcomputer is supplied with the gross article weight from a scale and with price per unit weight data from a manual keyboard. Tare weight data may be entered either through the manual keyboard or automatically from the scale. The microcomputer computes a net weight and a value for each weighed article. The net weight, the price per unit weight and the value are indicated on a digital display and may be printed on a label. Filtering circuitry prevents jitter in the article weight supplied from the scale to the microcomputer and the display caused by small vibrations in the article or the scale.

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Westerville, OH, United States of America

Edward G Pryor