RECORDING MATERIAL DISCRIMINATION DEVICE AND IMAGE FORMATION DEVICE

To solve a problem that the detection accuracy of a recording material is deteriorated depending on a position where the recording material is detected due to the influence of unevenness of the basis weight of the recording material which is not uniform and uneven in the whole area of the recording material.SOLUTION: A recording material discrimination device includes: transmission means for transmitting ultrasonic waves; drive means for outputting a drive signal for transmitting the ultrasonic waves from the transmission means; reception means for receiving the ultrasonic waves; and control means for discriminating the type of the recording material. The control means determines the type of the recording material on the basis of: a first value determined by receiving the ultrasonic waves via the recording material by the reception means in a first mode in which the drive means outputs a first number of drive signals in a predetermined period and a second value determined by receiving the ultrasonic waves via the recording material by the reception means in a second mode in which the drive means outputs a second number of drive signals larger than the first number in a predetermined period.SELECTED DRAWING: Figure 9 【課題】 記録材の坪量は記録材の全域において均一ではなくムラがある。このムラの影響により記録材を検知する位置によって記録材の検知精度が低下してしまう虞があった。【解決手段】 超音波を発信する発信手段と、前記発信手段から超音波を発信させるための駆動信号を出力する駆動手段と、超音波を受信する受信手段と、記録材の種類を判別する制御手段と、を備え、前記制御手段は、前記駆動手段に所定期間において第１の数の駆動信号を出力させる第１のモードにおいて、記録材を介した超音波を前記受信手段で受信した第１の値と、前記駆動手段に所定期間において前記第１の数よりも多い第２の数の駆動信号を出力させる第２のモードにおいて、記録材を介した超音波を前記受信手段で受信した第２の値と、に基づき、記録材の種類を判別する。【選択図】 図９