| 摘要 |
PROBLEM TO BE SOLVED: To provide a grammage detection sensor which can detect the grammage of a recording material with high accuracy irrespective of a change in a surrounding environment even when images are continuously formed on a plurality of recording materials.SOLUTION: The grammage detection sensor according to the present invention includes: a transmission unit which transmits an ultrasonic wave; a reception unit which receives the ultrasonic wave transmitted from the transmission unit; and a control unit which detects the grammage of a recording material, when a plurality of recording materials are continuously conveyed between the transmission unit and the reception unit, on the basis of a first ultrasonic wave received by the reception unit after the ultrasonic wave is transmitted by the transmission unit between a preceding recording material and a recording material following the preceding recording material, and a second ultrasonic wave received via a recording material by the reception unit after the ultrasonic wave is transmitted by the transmission unit. |
