| 摘要 |
<p>PURPOSE:To reduce an error in time clocking due to temperature variation by outputting a counting result, obtained by using a crystal for source oscillation, as data and correcting counter contents with a watch error value found from the inspection output of ambient temperature. CONSTITUTION:The source oscillation which is outputted by the cooperation between an oscillator 8 and a crystal oscillation circuit 17 with crystal 7 is frequency-divided 9 and counted up by timer and crystal counters 1 and 2, and the counter 2 is connected to an arithmetic circuit 4. The circuit 4 finds the watch error value of the crystal 7 at optional time intervals based upon the output of a temperature sensor 13 which detects the ambient temperature. The output of a counter 5a which integrates the output of the circuit 4 and the contents of the counter 1 are added by the adding circuit 5b of a correcting circuit 5 and the addition result is corrected and stored in the counter 1. The oscillation frequency of the crystal 7 is easily affected by the ambient temperature, but the error in time clocking due to variation in the ambient temperature becomes small.</p> |
