| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect an open state of a paper feed cassette by a paper residual quantity sensor without separately providing an opening/closing sensor of the paper feed cassette.SOLUTION: Paper residual amount sensors 31 and 32 detect paper residual amounts in paper feed cassettes 11 and 12. A storage device 51 stores paper residual amount values indicating the paper residual amounts detected by the paper residual amount sensors 31 and 32. A paper residual amount acquisition part 52 acquires the paper residual amount values indicating the paper residual amounts detected by the paper residual amount sensors 31 and 32, then, updates paper residual amount values stored in the storage device 51 with the acquired paper residual amount values if the paper residual amount values detected by the paper residual amount sensors 31 and 32 indicates no paper shortage. A cassette open/close determination section 53 determines that the paper feed cassette is in an open state when the paper residual amount values stored in the storage device 51 is larger than a prescribed threshold if at least one of the paper residual amount values detected by the paper residual amount sensors 31 and 32 indicates paper shortage.SELECTED DRAWING: Figure 2 |
