Patent ID: 6201577
Filing Date: 2001-03-13
Classification: H04N

Abstract:
An NTSC film detector for detecting 24 frame/second sources in NTSC television signals, the detector receiving a field motion signal indicating motion from interlaced field to interlaced field, comprisingan accumulator responsive to said field motion signal and outputting an indication of motion during an entire field,a minimum of fields detector responsive to the accumulator output for a predetermined number of fields and outputting an indication of motion during the field having the minimum motion,a subtractor receiving the accumulator output and the minimum of fields detector output and outputting the difference thereof,a fields weighted averager responsive to the accumulator output and outputting an indication of the weighted average of motion for a predetermined number of fields,a variable threshold receiving the output of said subtractor and having its threshold controlled by the output of said fields weighted averager and outputting a binary signal having one sense for a moving field and another sense for a non-moving field, anda pattern detector receiving the output of said variable threshold for determining the occurrence of a predetermined pattern of moving and non-moving fields.