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:
Jun. 27, 1995
Filed:
Mar. 29, 1994
Tateo Masaki, Chiba, JP;
Uniden Corporation, Chiba, JP;
Abstract
An automatic tuning system in a high-speed scanning radio receiver provided with (a) a noise squelch circuit, first and second detecting circuits, first and second control circuits, a CPU circuit providing PLL data, and a scanning stop function. The squelch circuit generates a first (SP) signal when a decreasing trend in a noise detection voltage becomes lower than a preset reference voltage. The first detecting circuit judges whether or not the SP signal is generated within first predetermined time period (M1). The first control circuit causes the second detecting circuit to detect whether or not the SC signal is generated within a second predetermined time period (M2; M2>M1) when the first detecting circuit detects the SP signal has been generated, and the second control circuit causes the second detecting circuit to detect whether or not the SC signal is generated within a third predetermined time period (M3; M3>M1) when the first detecting circuit detects the SP signal for the current channel being scanned has not been generated and the SP signal for the preceeding scanning was generated. Accordingly, even if no SP signal for the current channel being scanned has been detected, the system is capable of securely detecting the SC signal by extending a SC signal monitoring period to the period M3, and thus securely stopping searching whenever the SC signal is generated.