| 摘要 |
PURPOSE:To provide an inexpensive sheet deciding device which can decide the types of sheets with high accuracy. CONSTITUTION:The light emitting elements are arranged in plural rows and in the direction orthogonal to the transfer direction of a sheet S, and the photosensors 12-i are set at the positions corresponding to the light emitting elements respectively. At least one of these sensors 12-i can receive the light which is emitted from the corresponding light emitting element and cut by the side edge SE of the sheet S. A sheet length detector means detects the length L (S) of the sheet S based on the ratio set between the output of a photosensor which is entirely shielded from the light by the sheet S and the output of a photosensor partly shielded from the light. Then a pattern comparator means acquires the pattern data on the sheet S based on the time series output of the photosensor and compares the acquired pattern data with the reference pattern data corresponding to the type of the sheet S. In such a constitution, the type of the sheet S is decided based on the detected length L (S) of the sheet S and the result of comparison obtained by the pattern comparator means. |
