United States Patent im
Miyazaki et al.
US005786872A [ii] Patent Number: [45] Date of Patent:
[54] MOTION DETECTION CIRCUIT
CALCULATES DIFFERENCE BETWEEN
INPUT VIDEO SIGNAL AND ONE FRAME-
PERIOD SIGNAL
[75] Inventors: Shinichirou Miyazaki; Masaharu Tokuhara. both of Kanagawa. Japan
[73] Assignee: Sony Corporation, Tokyo. Japan
[21] Appl. No.: 685,974
[22] Filed: Jul. 22, 1996
[30] Foreign Application Priority Data
Jul. 26, 1995 [JP] Japan 7-190014
[51] Int CI.6 H04N9/78
[52] U.S. CI 348/669; 348/670
[58] Field of Search 348/663. 664.
348/665. 666. 667, 668, 669. 670. 699;
H04N 9/77, 9/78, 5/14. 9/64
[56] References Cited
U.S. PATENT DOCUMENTS 4,930,012 5/1990 Fujita 348/666
5,023,713 6/1991 Nishigori 348/666
5,063,438 11/1991 Faroudja 348/667
5,325,186 6/1994 Ishizuki et al 348/663
5,412,434 5/1995 Taniguchi et al 348/669
5,475,445 12/1995 Yamaguchi et al 348/663
5,500,686 3/1996 Yamaguchi et al 348/663
Primary Examiner—Mark R. Powell
Assistant Examiner—John W. Miller
Attorney, Agent, or Firm—Jay H. Maioli
[57] ABSTRACT
An apparatus and method in which a difference between lines in an input composite video signal is calculated. The difference is compared with a specified threshold to detect chrominance correlation. A difference between lines in a composite video signal which is delayed for a one-frame period is calculated. The difference is compared with the specified threshold to detect chrominance correlation. The difference between these chrominance correlations is calculated and is used as a motion detection signal. When this frame difference is smaller than a specified threshold, the motion detection signal is forcibly set to 0.
9 Claims, 11 Drawing Sheets
