Patent ID: 7576801

Claim:
A signal processing apparatus comprising: a first delaying means for delaying a luminance signal by an amount of one field, said first delaying means including no more than a single delay unit such that said first delaying means outputs a single delayed version of said luminance signal; a processing means for generating a difference signal indicating a difference between said luminance signal delayed by an amount of one field by said first delaying means and a not delayed luminance signal for each field; an adding means for accumulating difference signal values generated by said processing means on a field-by-field basis to generate a cumulative difference signal; a second delaying means for delaying said cumulative difference signal generated by said adding means by an amount of one field; and a judging means for comparing the cumulative difference signal generated by said adding means and said cumulative difference signal delayed by an amount of one field by said second delaying means and judging the format of said luminance signal based on the result of said comparison.