The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 22, 1983
Filed:
Mar. 03, 1981
Kabushiki Kaisha Suwa Seikosha, Tokyo, JP;
Abstract
A mode coupled tuning fork type quartz crystal vibrator utilizing two different vibrational modes is provided. The vibrator includes at least one electrode on each tuning fork arm for adjusting the resonant frequency of the main vibration and an electrode for adjusting the frequency-temperature characteristic of the vibrator. The main vibration is in the flexural mode (F.sub.1) and the sub-vibration is in the torsional mode (T.sub.0). The resonant frequency of the first overtone in the flextural mode is designated by f.sub.F and the resonant frequency of the fundamental vibration in the torsional mode is denoted by f.sub.T. The difference between f.sub.F and f.sub.T defined as .DELTA.f=f.sub.F -f.sub.T determines the frequency-temperature characteristics of the mode coupled vibrator. The electrodes for adjusting f.sub.F are substantially triangular in shape and the electrodes for adjusting f.sub.T are substantially rectangular in shape. These electrodes are disposed at positions near the top of each tuning fork arm and on both principal surfaces of the vibrators. The resonant frequencies are adjusted by removing a portion of electrode material or adding a strip of metal to the electrode. Preselected oscillation frequency and frequency-temperature characteristics in the form of a cubic curve at ambient temperatures are obtained by first adjusting .DELTA.f to a preselected value .DELTA.f.sub.O and then adjusting f.sub.F to a preselected value f.sub.F0 at the same time maintaining .DELTA.f at the value .DELTA.f.sub.0.