Patent ID: 8023037
Filing Date: 2011-09-20
Classification: H04N

Abstract:
1. A focus-adjustment signal generating apparatus comprising: a filter configured to extract a high-frequency component at a specific frequency or higher from a luminance signal of an input video signal; a comparator configured to compare an absolute value of the high-frequency component with a specific reference value, to output a first detection signal when the absolute value is equal to or larger than the reference value whereas a second detection signal is output when the absolute value is smaller than the reference value; an extender configured to extend an output period of the first detection signal according to a period indicated by a period-length setting signal, to output an extended first detection signal; and a selector configured to select a first chrominance difference signal that indicates a specific color in response to the extended first detection signal whereas a second chrominance difference signal is selected to indicate an achromatic color in response to the second detection signal, the first or the second chrominance difference signal being output as a focus-adjustment signal; wherein the extender includes: