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. 05, 2013
Filed:
Sep. 23, 2010
Manabu Ito, Saitama, JP;
Hiroyuki Mitome, Saitama, JP;
Takeo Oita, Saitma, JP;
Nihon Dempa Kogyo Co., Ltd., Shibuya-Ku, JP;
Abstract
The present invention relates to an oven controlled crystal oscillator that can obtain stable oscillation frequency by reducing a temperature change in an oscillation element. The oven controlled crystal oscillator comprises; a heat-conducting plate mounted on one surface of a circuit board, a crystal resonator mounted on a surface of the heat-conducting plate opposite to the surface of the circuit board, an oscillation element constituting an oscillation circuit together with the crystal resonator, and a thermistor that detects temperature of the crystal resonator, a heating resistance which heats the crystal resonator, and a temperature control element including at least a power transistor, to constitute a temperature control circuit together with the thermistor and the heating resistance. In the oven controlled crystal oscillator, two or more open areas communicating with the heat-conducting plate at least in the thickness direction thereof are formed on the periphery of the heat-conducting plate at positions point-symmetric with respect to the crystal resonator, and one or more of each of the power transistor and the heating resistance are arranged in the same number in all of the open areas.