| 摘要 |
<P>PROBLEM TO BE SOLVED: To correct an output frequency for temperature with high accuracy in an oscillation device which corrects its output frequency on the basis of the result of environment temperature detection. <P>SOLUTION: A first and a second crystal vibrator are composed with a common crystal piece, and the oscillation outputs of a first and a second oscillation circuit which are respectively connected to these crystal vibrators are assumed to be f1 and f2. The oscillation frequencies of the first and the second oscillation circuits at a reference temperature are respectively assumed to be f1r and f2r, and a value corresponding to a differential value between a value corresponding to a difference between f1 and f1r and a value corresponding to a difference between f2 and f2r is handled as a temperature at that time. Then, a first correction value is found by a frequency correction value approximation equation of f1 on the basis of the value corresponding to the differential value, and from a correction residual which is a difference between the first correction value and a measured frequency correction value, a second correction value for cancelling the correction residual is found. Thereafter, a frequency correction value is found from the sum of the first and the second correction values. <P>COPYRIGHT: (C)2013,JPO&INPIT |
