| 摘要 |
PURPOSE:To retrieve a desired frame of a roll film accurately without any error by making a correction corresponding to the difference between the counted value of blip marks and an expected counted value or outputting an alarm signal if the counted value of blip marks is different from the counted value expected at a main frame side when the 2nd mark is detected. CONSTITUTION:When a decision circuit L judges that the error occurrence frequency gamma/beta based upon the number gamma of errors and the number beta of marks is >=1/10, the alarm O is generated to display device or film abnormality. When the result obtained by the decision device L is <=1/10, a decimal value X is fractionized by a fractionizing device P so as to correct the counted value alpha of blip marks 2 by the value of the decimal part X of the quotient. When the decimal value X less than 0.3, a computing element Q performs arithmetic alpha= N.Y, and when X>0.7, a computing element performs arithmetic alpha=N.(Y+1). When 0.3<=X<=0.7, it is judged that which of the computing element Q and R should perform arithmetic can not be decided on, and an alarm S is generated. Thus when arithmetic for corrections is performed, a mark detection command signal C is outputted preferentially to the output of a counter F as the outputs of the computing elements Q and R, and the counted values alpha and beta of counters F and J are corrected. |
