Title:
周波数同期検出回路及びこの周波数同期検出回路を備えた信号処理装置
Document Type and Number:
Japanese Patent JP4309034
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To detect the occurrence or elimination of the fluctuations of the horizontal and vertical periods for a video signal, in a short time. SOLUTION: A horizontal synchronization signal and a burst signal included in a video signal are respectively extracted by a horizontal synchronization extracting circuit 301 and a burst extracting circuit 306. Subcarrier clocks are extracted from the synchronization signal and the burst signal, by using crystal oscillators 302 and 307 for generating local oscillation signals which mutually turn into identical frequency, and are respectively input to N-fold counters 305 and 310. The counters 305 and 310 match synchronizations of both the subcarrier clocks, predetermined N samples are counted, and a pulse signal of N-sample period is generated. Thereafter, a comparator 311 compares both the output pulse signals of the counters 305 and 310, and the number of times of non-coincidences of the pulses is detected by a deciding circuit 312.
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Inventors:
Nobutaka Shinohara
Application Number:
JP2000275024A
Publication Date:
August 05, 2009
Filing Date:
September 11, 2000
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
H04N5/073; H04N5/91; H04L7/00; H04N5/95
Domestic Patent References:
| JP8331597A | ||||
| JP6005256U | ||||
| JP11196381A |
Attorney, Agent or Firm:
Takehiko Suzue
Sadao Muramatsu
Ryo Hashimoto
Satoshi Kono
Makoto Nakamura
Shoji Kawai
Sadao Muramatsu
Ryo Hashimoto
Satoshi Kono
Makoto Nakamura
Shoji Kawai