Combined thermometer and calculator

Claim 1

A combined electronic thermometer and calculator device, comprising: an electronic calculator comprising key matrix input means, key signal input terminals for receiving key signals from said key matrix input means, logic means for performing arithmetic operations with data input via said input terminals, and display means for displaying the results of said arithmetic operations; said device further comprising: oscillating means for providing a first waveform signal at a first frequency dependent upon temperature; dividing means for dividing said first waveform signal for providing a second waveform signal of a second frequency for defining a first period of time dependent upon temperature; means for generating reference clock pulses at a third frequency which is greater than said second frequency; means for counting said reference clock pulses during said first period of time to obtain a first count; means for inputting a signal representing said first count of said clock pulses to said logic means; means for generating a third waveform signal for defining a second period of time which is independent of temperature; means for counting said reference clock pulses during said second period of time to obtain a second count; means for inputting a signal representing said second count to said logic means; said logic means comprising means for determining temperature based upon a ratio of said first and second counts; and means for displaying temperature in said display means of said calculator.