Perishable good integrity indicator
First Claim
1. A perishable good integrity indicator comprising:
- clock means for outputting a first clock signal which does not substantially vary as a function of temperature;
second clock means for outputting a second clock signal which varies as a function of temperature;
counter means for producing a count value as a function of said second clock signal during a determinable time period;
data means for receiving said count value, translating said count value into a time temperature value representing the relationship of time and temperature during said time period; and
summing means for summing said time temperature values output by said data means over time and outputting a cumulative time temperature signal.
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Abstract
A perishable good integrity indicator includes a first oscillator for outputting a first clock signal which does not substantially vary in response to temperature. A second oscillator outputs a second clock temperature which varies as a function of temperature. A counter counts the pulses of the second clock signal during a time period determined by the first clock and outputs a count value. A data table receives the count value, translates the count value into a time temperature value representing the relationship of time and temperature during the time period and outputs the time temperature value to an adder. The adder adds the time temperature values output by the data table over time and outputs a cumulative time temperature value corresponding to shelf life for a product.
109 Citations
23 Claims
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1. A perishable good integrity indicator comprising:
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clock means for outputting a first clock signal which does not substantially vary as a function of temperature; second clock means for outputting a second clock signal which varies as a function of temperature; counter means for producing a count value as a function of said second clock signal during a determinable time period; data means for receiving said count value, translating said count value into a time temperature value representing the relationship of time and temperature during said time period; and summing means for summing said time temperature values output by said data means over time and outputting a cumulative time temperature signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A perishable good integrity indicator comprising:
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clock means for outputting a first clock signal which does not substantially vary in response to temperature; second clock means for outputting a second clock signal which varies as a function of temperature; counter means for producing a count value as a function of said second clock signal during a determinable time period; data means for receiving said count value, translating said count value into a time temperature value representing the relationship of time and temperature during said time period; and summing means including a first counter for counting to a predetermined number as a function of said first clock signal and a second counter counting each occurrence of said first counter counting to said predetermined number outputting a cumulative time temperature value in response thereto;
said first counter beginning its count at a value determined by said time temperature signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An oscillator self calibrator for calibrating an oscillator clock signal comprising a divider for receiving said oscillator clock signal and generating a first divided clock signal;
- a reference gate providing an enabling signal having a time period;
a counter receiving said enabling signal and counting said divided clock signal during said time period and producing a count value as an output, said divider receiving said count value and dividing said oscillator clock signal by said count value to produce a calibrated clock signal.
- a reference gate providing an enabling signal having a time period;
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22. An oscillator self calibrator for calibrating an oscillator clock signal comprising a divider for receiving said oscillator clock signal and generating a first divided clock signal;
- a reference gate providing an enabling signal having a time period;
a counter for counting said clock signal during said time period and producing a count value as an output, said divider receiving said count value and dividing said clock signal by said count value to produce a calibrated clock signal, said oscillator clock signal not varying as a function of temperature and said reference gate outputting an enabling signal for a time period which does not substantially vary with temperature to calibrate said oscillator clock with respect to time.
- a reference gate providing an enabling signal having a time period;
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23. An oscillator self calibrator for calibrating an oscillator clock signal comprising a divider for receiving said oscillator clock signal and generating a first divided clock signal;
- a reference gate providing an enabling signal having a time period;
a counter for counting said clock signal during said time period and producing a count value as an output, said divider receiving said count value and dividing said clock signal by said count value to produce a calibrated clock signal, said oscillator clock signal having a frequency which varies as a function of temperature and said reference gate providing an enabling signal for a time period which varies as a function of temperature to calibrate said clock signal with respect to temperature.
- a reference gate providing an enabling signal having a time period;
Specification