Patent ID: 9250215
Filing Date: 2016-02-02
CPC Classification: B65H,G01N,G03G

Claim Text:
1. An ultrasonic wave detection apparatus comprising: a transmission unit configured to transmit ultrasonic waves at a first frequency and ultrasonic waves at a second frequency that is higher than the first frequency; a reception unit configured to receive the ultrasonic waves at the first frequency transmitted by the transmission unit and output a first signal including a first plurality of peak values corresponding to the ultrasonic waves at the first frequency being received, and receive the ultrasonic waves at the second frequency transmitted by the transmission unit and output a second signal including a second plurality of peak values corresponding to the ultrasonic waves at the second frequency being received; and a control unit configured to calculate a first time interval from when the transmission unit transmits the ultrasonic waves at the first frequency to when a predetermined peak value in the first plurality of peak values is obtained, and a second time interval from when the transmission unit transmits the ultrasonic waves at the second frequency to when a peak value in the second plurality of peak values is lastly obtained during the first time interval, wherein the control unit detects a position of the predetermined peak value in the order of the first plurality of peak values based on a time difference between the first time interval and the second time interval; and wherein a grammage of the recording material is determined based on the detected position of the predetermined peak value or image forming conditions of an image forming unit are controlled based on the detected position of the predetermined peak value.