Dual standard PAL/SECAM receiver circuitry
Patent 4309719 Issued on January 5, 1982. Estimated Expiration Date: 
October 31, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 31, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2892024 2910528 InventorAssigneeApplicationNo. 06/202503 filed on 10/31/1980US Classes:348/555, For receiving more than one format at will (e.g., NTSC/PAL)348/712Luminance channel circuitryExaminersPrimary: Richardson, Robert L.Attorney, Agent or FirmInternational ClassH04N 9/64 (20060101)Foreign Application Priority Data1979-01-09 GBAbstractIn a dual-standard PAL/SECAM color TV receiver, an identification system provides a mode-switching output, permitting automatic switching of the receiver between a PAL-reception mode of operation and a SECAM-reception operating mode, in dependence upon the PAL or SECAM nature of the transmission received. In the SECAM-reception mode, a PAL decoder receives the chrominance component output of a SECAM-PAL transcoder; in the PAL-reception mode, the PAL decoder receives chrominance signals which bypass the transcoder. Luminance signal channel of the dual-standard receiver includes a switchable luminance signal delay line in cascade with a chrominance component trap circuit. Switchable delay line is controlled by mode-switching output of identification system such that delay line is interposed in luminance signal path only during SECAM-reception mode operation. Delay magnitude provided by delay line substantially matches difference in delays suffered by chrominance information during operation in the respective modes. Trap circuit, providing luminance delay substantially compensating delay suffered by chrominance information during operation in PAL-reception mode, includes resonant circuits tuned respectively to upper and lower SECAM subcarrier resting frequencies.Other References
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